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Georgek591
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PostPosted: 15:48 - 02 Jan 2017    Post subject: Bike not running right Reply with quote

I have recently purchased a Honda CBR125 cheaply off a family member. Before they owned it a previous owner had crashed it and the bike had been written off. Someone brought it and repaired it using parts from other bikes (Electronics, front light, speedo, temp, rev count Etc as the front was smashed to pieces). I know the bikes engine has been rebuilt and the exaughst has been replaced by a Yoshimura USA (Off the topic I need to get a baffle for this at somepoint as it's very loud and most likely illegal so if you know where I could pick one up cheap it would be much appreciated). The bike is also missing a lot of faring which I hope to replace at some point.

Getting to the point, I know not to expect much from this bike as it's really a hunk of junk but the bike struggles to reach 60 on a flat surface with no wind (I'm aware there's many threads discussing this). I believe the bike is running too lean as it often dies when cold after starting (If I don't rev the bike a lot it will take about 5-10 starts) also when decelerating it makes some lovely popping noise but I believe this is due to it being too lean.

What I need to know, what screw can adjust the fuel to air ratio and where is it. I've read many posts but have been confused by them as I can't tell if their talking about the idle or the air/fuel screw or if their the same thing.

I'm planning on replacing the spark plug but I don't have the correct tools to take it out at the moment (would of checked the spark plug to confirm if it's running to lean but I can't). I am planning on cleaning out the carb and getting a new rear sprocket and chain and replacing the fairing.

I'm aware this bike probably isn't worth the hassle but it's all I can afford to get me around at present. I'm not sure what parts have been replaced on this bike but recently the throttle cable was replaced as it snapped so I'm assuming the bikes got a fair amount of worn parts.

Bike info(if it helps) - CBR125R 2007, Rebuilt engine, Yoshimura USA exaughst, all electronics on the handle bars are gone apart from an only Suzuki speedo (No temp gauge, rev count or mileage), a lot of the elecrronics have been rewired as there from other bikes(Indicators, headlamp, ignition), I believe the rear brake has a cable and the front is hydraulic.

Any help much appreciated. Can supply photos if anyone needs. Thanks
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CBRMAN94
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PostPosted: 23:06 - 02 Jan 2017    Post subject: Reply with quote

That sounds about right for a CBR125 without a fairing. The fairings help a lot!

As for the popping, That's pretty normal on the aftermarket exhausts too. It's happened on all the ones i've had on my previous CBR125s

It might run slightly better with a carb clean and a new plug but it does sound like it's fine to me and i wouldn't be messing with A/F ratios without knowing there is a problem

And all CBR125s have fluid operated front and rear brakes Thumbs Up
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Georgek591
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PostPosted: 00:57 - 03 Jan 2017    Post subject: Reply with quote

Thanks for the help. Do you know how much the fairing will help with acceleration and top speed? Also I think the rear brake was replaced after the accident as there's a cable and no little hydraulic brake fluid box. Is the dying when starting normal or shall I turn the idle up a little?

Another thing I've noticed is that when riding in 5th I can get to 60 slowly but at 60 the bike sounds like the engines gonna explode and when you change into 6th unless you have a tailwind or your going downhill you lose a lot of speed and can't accelerate. Going from 5th to 6th also can be hard as it often misses sixth and the engine revs to the limit and you have to pull in the clutch and by then you need to change back into 5th to get your speed back. I'm assuming this is due to the bike being in poor condition.

Gonna get the bike serviced soon and hopefully with faring and a clean carb she might run a bit smoother.
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Teflon-Mike
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PostPosted: 07:04 - 03 Jan 2017    Post subject: Reply with quote

Georgek591 wrote:
Thanks for the help. Do you know how much the fairing will help with acceleration and top speed?


Not a lot. Is the short answer.

Force = Mass x Acceleration. So you get more acceleration from more force (power) and less mass (weight). BUT. CBR125 is a light bike to begin with. It only weighs about 125Kg, but the power has to shift that mass plus that of the rider, probably another 60-70Kg. The difference a couple of Kg of bodywork will make to the 'all up' power to weight ratio really is pretty negligible.

Top Speed? Likewise. Power = Force x Speed. Force you are working against is Drag mostly wind resistance, which increases, and factorialy with speed. It is also most significantly proportional to frontal area, ad frontal area alone; the 'aerodynamics' of bodywork, are again small potatoes in the equation.

For the typical frontal area presented by a person on a motorbike; it takes just 3bhp to go 30mph, 9bhp to go 60mph, 27bhp to go 90mph, and 81bhp to go 120mph. Ie for every +30mph you need aprox 3x the power.

With that factorial 'ramp' of wind resistance; up to about 100mph, the 'saving' on drag that a faring can offer, is notably small tending to negligible, and they really have little or no effect at less than 60mph; you only really see any benefit from a faring on top speed, at over 120mph or so.

A 'naked' 60bhp Diversion can do 'about' 115-120mph. A sport-faired Kawasaki KR1 with similar 60bhp, can just about nudge 130mph, though the fairing is only partly to blame; lower narrower handlebars reducing frontal area play as large a part; In 1948, Rolie Free took a Vincent Black Shadow, to 150mph on the Bonaville salt-flats, with just 60bhp and no fairngs at all... by stripping to his Y-Fronts and lying flat on the tank with his feet out behind the back mudgard... mad bugga.... but full enclosed cigar streamlers, with a similar 60bhp will only get perhaps 20-30mph more.

This gives you some references for the effectiveness of streamlining; Rolie Free's completely un-faired run shows how big a difference 'just' reducing frontal area makes; 30mph over 120, about 25%. Adding theoretically 'perfect' streamlined cigar shape fairing to that, adds only another 10% or so, but, probably only half that 10% is down to the slippy bodywork, large chuk down to further reduction of the frontal area, dropping lay-down rider down to near ground level.

So small difference on a bike that only just has the power to go 70mph in ideal conditions REALLY is inconsequential. FWIW, I've clocked a GPS recorded 70mph 2-up on a 'naked' 13bhp Honda CB125 Twin; the fairing 'really' isn't doing anything to aid top speeds on such a low powered bike at these sort of velocity.

Georgek591 wrote:
Another thing I've noticed is that when riding in 5th I can get to 60 slowly


That's an interesting nugget.

There is a phenomona I am always explaining to newbs about 'short shifting'....

Georgek591 wrote:
the bike sounds like the engines gonna explode


Because of that 'nugget' which suggests its probably exactly what you are doing!

OK, takes about 9bhp to go 60mph, BUT whilst the spec sheet or sales brochure may say a bike has 10 or 13bhp, that is NOT the amount of power it 'always' delivers. That is 'peak' or 'max' power, and it's only available at the peak power engine revs, at wide-open-throttle.

Typical 4-stroke single 125, has about 10bhp at around 10,000rpm. Or about 1bhp per 1000 revs. So at tick-over it barely offers 1bhp, at 2,000 2bhp, 3,000 3bhp etc.

Remember, only takes 3bhp to go 30mph, SO you can go that fast with as little as 3000rpm... and lets assume that the gearing in 'top' is set to offer 1000mph at 10,000rpm,;

Now, 1ooo rpm=1bhp &10mph, 2ooo rpm = 2bhp & 20mph , 3ooo rpm =3bhp & 30mph, 4ooo rpm =4bhp & 40mph, 5ooo rpm=5bhp & 50mph, 6ooo rpm=6bhp & 60mph, 7ooo rpm = 7bhp & 70mph, 8ooo rpm = 8bhp & 80mph, and.... ah! Spot the problem?

Takes 9bhp to go 60mph, but at 6,ooo rpm the engine's only delivering 6bhp.. up to around 50-55mph, the straight line of increasing engine power is higher than the 'curve' of increasing drag. They cross somewhere at around 50-55mph, and THAT is as fast as the bike will go, IF you try accelerating through that speed in top gear.

Engine has the 'potential' to make more power and go faster, but only if you can get the revs up to where that power is on offer.... the bike's 'topped out' and to go faster, you need to change down a gear to get the revs 'up' and go faster.

Which seems counter intuitive; lower gears go slower, higher gears go faster, using lower gear to go faster doesn't seem'right'. Whilst they have been hoofing up the cogs and probaly got into top before 40mph, because, newbs feel they have to do 'something' and gears are something to do, they feel they can do, and probably aught to.... especally if the engne 'sounds' like its screaming ts head off and about to explode....

Hence they 'Short Shift' changing 'up' too many gears too early, and making the engine labour at lower revs, and then wonder why t's loath to accelerate, in top through that 50-55mph 'top gear top out'.

CBR125, has six gears! WHY I do not know... marketing men probably.... it rally doesn't need them! It doesn't have the extended rev range or 'humped' power curve that begs them to keep it in the sweet spot. But it does give even more opportunity to get into a tangle of cogs, and for newbs to paranoid over remembering which one they are in, and the 'comfort' of being in top, and knowing that's what you're in 'cos it wont shift up no more!

Does any of this give you pause for thought or illumination?

Georgek591 wrote:
I'm assuming this is due to the bike being in poor condition. Gonna get the bike serviced soon and hopefully with faring and a clean carb she might run a bit smoother.


Before fixing the machine... elimnate operator error! It's a ten year old bike, worse a ten year old learner bike, that sounds like ts lead a hard life.. low powered leaner bikes usually do... but talk of Yoshimura race can and crashes, suggests more typical juvenile antics of trying to look and sound cool and go fast, and changing stuff that don't need changing and not the stuff that does!

A damn good service probably wot hurt a jot, and probably the best improvement you can make to the thing. That open can, wont be helping much if any, and risk is that if it's running rough on it now, it probably always has, and damage to the motor from it making engine run lean is already long done... I'm always suspicious when folk start diving in wanting to twiddle carburettors.... an awful lot of carburation problems AREN'T in the carburettor.... faulty exhausts... or mods! Are far more often the cause, as are clapped out engine internals.

Georgek591 wrote:
Is the dying when starting normal or shall I turn the idle up a little?.


Weather is cold. Are you using choke? How thick/cruddy is the oil? Carb adjustments come LAST on the to do list after all other service ops. So, change the oil. Adjust the clutch. Chage the sparker; make sure all else is 'good' then when the engine is 'warm' set the idle speed.

And hint; you do NOT adjust it with a screw! You adjust it with the throrttle slde. You twist the throttle, raise the revs, twist screw 1/4 turn, then lower slide back onto the stop, check idle speed and repeat if necessary. Screw adjusts the 'stop' position for the slide. Slide has a ramp in a slot on the side which rests on the screw; further 'in' you screw the screw, higher up the ramp the slide 'rests'. IF you just screw the screw 'in' it is as likely to just press ito the metal of the slide, and possibly justdent and or 'jam' it, as it is to move it 'up' and adjust the idle speed. ALWAYS adjust the idle screw with the slide 'lifted' by twisting the throttle.

MY ADVICE

1/ look at how you are riding the thing. Are you short shifting? Use the revs, not the gears!

As a rough guide; 1st to get moving, 2nd should take you to 20-25mph, and be all you need 'around the houses'. 3rd, aught take you comfortably from about 10mph to 40mph, and around town, the only gear you should need most of the time. 4th, when you are on faster 40+ limit roads without too many hazards to need to react to, and 5th on an 'open' road when you may max it out. 6th? Almost never should be needed, unless you are on a wide open duel cariageway, to knock the revs back or maybe eek out a couple of mph on a long down hill or with a tail wind.

But DONT over work the gears. Use the revs. Give yorself throttle response, and dont make work for yourself making so many unnecessary upshifts that beg more work making more unnecessary down shifts.

USE the revs... the engine (probably) wont explode! It may if its sufficiently prefucked, but then not revig it wont save it any. Its designed to be revved so rev it!

2/ Its an old and care worn bike with crash damage. Fairings wont make blugger all functional difference to it's performance; may make it look prettier, but they would be the last thing on my 'list' of stuff to worry about.

Getting it serviced, dealing with any functional damage and overhauling anything that is long past its sell by date, would be my main concern.

Most 125's have an anticipated service life of around 7 years. At 10, yours is heading into the boarder-lands of being a scrap-yard refugee, and at very high risk of being deemed "Beyond Economic Repair" just on a tally of a few more major routine service spares, like tyres chain & brake pads, LONG before you get to any serious over haul or repairs.

I would be very VERY cautious of how much this bike was 'worth', ether to me for the use I could get from it, or to any-one else I might convince to give me hard cash for it, before I started spending ANY money on the thing, trying to make 'improvements'..

and IF I did, and I'm inclined to that sort of optimism... I renovate old Honda CB125 Twins 'for fun' (or madness!), I'd want some confidence anything that I did or spent, would actually achieve a 'useful' improvement worth the money or the doing... and remember... I kid myself that old Honda CB125 Twins are 'worth the doing'!!! So MY personal bar is pretty low to begin with, YET even I am somewhat wary your CBR should prove a worthy cause...

Biggest improvement you might find for the money and very little effort is to sell on as is and buy something 'better', that has more life still in it and not so likely to be in need of constant running repairs.

Biggest 'risk' with what you have, as it stands, is that its a money-pit in waiting, which will beg some small spend to keep it tickling along until something else needs fixing, which begs bigger spend, and so on and so on, each time, problems begging more work & more money, not to make it 'better' but just stop it getting significantly worse than it is, and the mounting tally of what you have already 'spent' being a perverse incentive to carry on chucking time money and effort at the thing so as not to 'waste' all the time money and effort you have to that point.

Think long and hard about it before you head down that route; short term, keeping it tickling along can prove for very very expensive for the miles, as well as frustrating for the performance and 'hassle' having to keep fixing stuff.

On the basis that the fastest bike is the one that actually 'works'; notion of trying to keep on top of essential maintenance to keep a tag end old CBR125 in service, with sub-standard performance, I WOULD seriously be weighing up the relative merits of a Chinky CG cone or middle aged YBR in comparison. A 'tidy' utility bike like that will usually look a darn site better than a clapped out sporty one, and it will probably offer as much real world performance, whilst offer more of it more of the time, for less hassle, effort or cold cash....

I really would, look at the alternates before heading down the potential money pit route with this one...

I would THEN probably chuck my conclusions out the window, and knowing me, decide to cut to the chase and tear the thing down and do a complete 'ground up' renovation and sort 'everything' up-front, once and for all... and in all likelihood end up spending three times as long as I expect, and five times as much money as its worth.... B-U-T.... I kid myself that playing spanners is 'fun', and worth it to me, if no one else....

But it's your call; and my advice is to seriously weigh up the worth before you do anything to this bike, and be SURE its worth it.
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Georgek591
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PostPosted: 15:21 - 03 Jan 2017    Post subject: Reply with quote

Thanks for the advice! I had considered if it was worth the money but for around 300 I thought it was a cheap bike that would get me from a to b untill I can afford something a little better. As I only have my A1 at present I'm sticking to 125cc and can't get anything better.

As you have said it's probably not worth spending money on it do you know of anywhere online I can get a baffle for the exaughst and I'll just run it for a year and buy a decent 125 when I have the funds available.

Also you mentioned that running with a Yoshimura could make the bike run lean and damage the engine. I was thinking of transferring this exaughst to my new bike when I get it. As I have little knowledge in this area what's the damage this could do to the engine. am I better scrapping the CBR and getting a scorpion for my new bike or do all aftermarket exaughsts have this effect.
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Teflon-Mike
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PostPosted: 17:54 - 03 Jan 2017    Post subject: Reply with quote

You dont get much in the learner legal world worthy of an MOT for 300 notes; I have paid more for spares or repairs projects! At that kind of cash it's tempting to run it till it stops, break it for spares and stick what dont sell in six weeks in a skip. If the wheels keep turning for six months you'll have had your money's worth from the use.

So you have passed A1, you're not on L's? Goo-oood MAN! So when you say save for something 'better', why another 125? If you are restricted to A1 by age, you will be literally weeks off being A2 eligible n a years time when you have saved up, if you aren't already or sooner; on which score, notion begs, that having been round the houses once, doing it over for an A2 aught to be a walk in the park; should only need a few hours to get familiar and comfy with an A2 bike, and A2 bike to do the tests on. That opens the door to'big-bikes', which, if you are on a restricted budget, looking to run tag end old 'hacks', 'banger-nomics' can work much more to your favor.

125's, the great unloved, tend to live hard harsh lives in the hands of learner's and commuters neither of whom tend to be particularly clued up or bothered about looking after them, and they all rag the shit out of them, when they aren't the most 'hardy' machines to begin with, built down to a weight and a price to start with.

I the barrel dreg market, pound per quid you will get a lot more big-bike for your pennys than a tidler; as they dont command the 'Learner' premium, and were usually more 'Heavy Duty' when new, and owned by qualified licence holders, so tend not to suffer the worst excesses of Learner numptiness.

Running costs tend to be higher, but lacking the Learner-Loading, more 'sensible' big bikes are usually cheaper to insure, especially over a more 'sporty' 125, and that saving, can be significant to offset other running costs. Fuel consumption, tends to be higher, but not necessarily that much. Ragging a 125 tend to dent the economy they might provide, while gentling a big-bike, tends to see them return better than book, and often by a considerable margin. Service spares are where they 'bite'; B-U-T, in this world, you factor in a pair of tyres, C&S kit and new brake pads when you buy it, and expect them to out-last the bike!

On which basis; you might consider adapting the plan, and ponder a short A2 Course and then things like ER5's or CB500's, as the 'next step' up the ladder.

Back to the CBR125; exhaust baffle? There's things called dB Killers on e-bay, that cost a few quid and psh into the pipe. I cant vouch for them, I have ever tried them. Safest bet would be a geuine 'stock' silencer; which you could probably pick up reasonably cheap, as most folk want the flashy 'race' noise makers. You'd probably be cash in hands selling on the one you have to buy a stocker or taking stocker in px for it!

Open pipes make the engine run lean. Science of 'why' gets complicated and is to do with gas velocity and the 'over-lap' when exhaust valve and inlet valves are open at the same time, screwing up the pressure signal that the carburetor 'sees'. But the net result is that the 'lack of back pressure' sees the air-fuel ratio lean out. Usual 'fix' is to up-jet to ritchen the mixture to compensate, but how much and which jet or jets and or needles need upping is something of a dark art.

If an engine runs grossly lean, then the results can be rather dire; a lean mix is prone to 'pre-ignition', catching fire before the spark plug lights it, which tends to rob power trying to push the piston back the way its come, making pressure before the piston has over centered, and increasing 'peak' cylinder pressures. Often called 'knock' and that can put rather large loadings on the big and little ends; usually more catastrophically detrimental though, the 'burn' is that much faster, and hotter, so the engine is likely to over heat; add 'spare' oxygen, and you can start to see pistons melting and valves 'burning out', though spark plug electrodes tend to be the first things to 'go'.

Either which way, it tends not to be great for engine longevity; BUT... how much life this motor got left in it anyway? Is it worth worrying too much about?

Not sure whether you mean scrapping the CBR... or the CBR's Yoshi lol 'silencer'. As said' 'safe' bet would be to see if you could get some-one to do a swap for a stock can. As is? It's a risk, but then the whole bike probably is... is it the biggest 'worry' on the list?

As to after-market pipes in general? No, they are all like this pretty much! Power is made 'in' the engine, not outside it, and the boys in Homatsu tend to spend an awful lot of time, and an awful lot of money, with big computers modeling different systems to get 'best' results.... which does tend to mean satisfying regulatory noise and emission regulations... that add 'some' compromise, but still; what they come up with teds to be pretty well 'optimised'.

After-Market 'cans' tend to be pretty simple bits of pipe, given very little development attention on ANY particular motorcycle, let alone the one you want to fit it to. Benefits of the things are marginal, tending to negligible, tending to worse than useless! They save weight and increase noise, by omiting the baffling. They seldom if ever do anything to 'improve' power, even is the motor is jetted to suit them. More often, they spoil power, putting flat spots into the power curve from screwing the carburation.

Best 'full' after-market exhaust systems; developed for a specific model of motorcycle, 'may' offer some power improvements over stock, IF the carburation is set up to suit them. Together, on a 100bhp motor, you 'might' with the best of the best, dyno developed system, from exhaust port to end pipe, gain about 4bhp at 'peak'.. but at the cost of smaller losses over more of the rev range, lower down, so on an 'area under the curve' basis, dont delver 'as much' as much of the time. And that's the 'best' of the best full systems.

So 4bhp on a 100bhp engine; 4%. On a 125, with closer to 10bhp... yeah, 0.4bhp at 'peak' is the 'best' you'd get for a 'full' properly developed, properly set up system. It's just not really worth it is it?

While a noisy end can? Unlikely to deliver any added power, likely to rob power; potentially do damage if carburation not properly set up, so All you'll do is piss off the neighbors and give the plod an easy collar to hand you an automotive ASBO!

Your call really....
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Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'
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Georgek591
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PostPosted: 05:47 - 04 Jan 2017    Post subject: Reply with quote

Call me childish but I love the sound of a nice exaughst and I think it makes riding more enjoyable. That said the Yoshimura is far to loud. CBR stock exaughsts look terrible and I would want to replace it for a better one anyway. If I keep the Yoshimura, reduce the noise and get a mechanic to fit it and set up the air/fuel would that eliminate it running too lean?

I'm restricted to 125 as I've newly passed my A1 so as much as I'd love a 600 I have to stick to a 125. I'm saving up money for a newer 125 at the moment and was planning on buying a newer CBR. Is this advisable? I know there's mixed views about CBR's, some people love them others think there what immature learners spend money on ruining and too and wrap around a tree.
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Teflon-Mike
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PostPosted: 12:47 - 04 Jan 2017    Post subject: Reply with quote

Georgek591 wrote:
Call me childish but I love the sound of a nice exhaust and I think it makes riding more enjoyable.

lol. 'Nice' exhaust.... Yeah... Laverda Jota on open Conti's. A Bevel Drive Ducati 900 on reverse mega's! A Velocette Thruxton on Brooklands 'fish-tail' even an air-cooled RD250 on 'spanies'.... Trouble IS it's NOT the exhaust that endows the 'tune'! Its the 'tune' that makes the music!

Chet Baker is one of Jaz's most regarded trumpet soloists, and hearing his haunting solo in Elvis Costello's 'Ship-Building' still make my stomach flutter; hand ME his horn, and I'd probably make a noise like wet whoopee cushion being sat on by a fat woman! It aint in the pipe, its what blows it, kid!

Opinions may differ... and my opinion almost certainly will depending on how long I've been in the saddle... I run an old air-cooled CB750, with a full system 4-1, that is err.. a bit raucous! Most of the time I appreciate it. My neighbors, bar one, actually 'like' it, but I live in a strange neighborhood! 2-Up on a touring weekend, with it spitting and popping and chucking flames out the back, like Idris the Dragon, coming down a long steep hill between terraced cottage, it's a little more embarrassing!!And after a hundred or more miles it's tending to get a bit tiring! But it does sound 'good' most of the time. A lot of it, though is that it's 750cc, which endows a bass and treble smaller singles just don't have, and air-cooling lets the over-tones of mechanical 'clatter' add to the orchestra.

To me, a lot of modern water cooled big-bore four's just sound like a sewing machine.. and when they have an open can, merely a 'loud' sewing machine!

Small singles? Like a lawn mower. On open pipes? A loud rusty lawn mower.. dying of terminal flatulence! Lol. The only 'little' engines that sound 'nice' are two-strokes... and even then, they need to be 'crisp' and have gears, or they just sound like a strangled strimmer!

The CB125's are a peculiarity; air cooled and with two moped sized pots, they tend to sound rather limpid; but they rev to 14ooo rpm! On a 2-1 Motad 'Reverse Mega, they almost sound quite good when they 'come on the pipe' and start to wail a bit! But it's in that 'tune' not the volume. Pipe's actually quite quiet & marked up 103dB ISTR in accordance with 80's regs!

But it's all a vanity... end of the day, how loud they are doesn't have much relation to how fast they are, or how useful they are, or how cheap they are to run! And 750 would probably have lost its open system years ago, bar for the fact it was what was on it when I got it, and would cost me money to swap it!

Georgek591 wrote:
I'm restricted to 125 as I've newly passed my A1 so as much as I'd love a 600 I have to stick to a 125. I'm saving up money for a newer 125 at the moment and was planning on buying a newer CBR. Is this advisable? I know there's mixed views about CBR's, some people love them others think there what immature learners spend money on ruining and too and wrap around a tree.


If you have just passed your A1, then you have done the exact same 'tests' to get any bike licence; and I don't suppose you will have done your A1 tests within a week of your 17th birthday, so even if you are in that 2-year period of 17-19 when is a 125 is all you can have, a far chunk is already passed and little should be left by the time you have saved up for a better bike.... and that is the only period any-one is 'restricted' to 125's.... other wise its entirely self imposed, to get access to bigger bikes, all you have to do is the bike tests, and you already done them once.

There are 'other' displacements apart from 50cc, 125cc, 600cc & 1000cc you know? Also 'styles' other than 'Super-Spurts'... which take it are what excite you?

Most if not all 600 Sports are pretty much outside the scope of A2 licence regs, and strategically so. Hence the CBR250 and 250/300Ninja to offer that style in an A2 compliant package; f you have to have that 'style'. But, there's a lot else out there, and the SV650 particularly offers that style, in a package that's A2 restrctable, and peculiarly affordable.

CBR125? Meh! It's not the bike, it's the expectations put on it. They are a regulation 125 Learner/Commuter in a play-suit, and FWTW not a complete 'joke', but they are an expensive indulgence for that pretend style. Greatest asset of 125 Learner/Commuters is 'Cheaps', and costing 2x the buy price, new or 2nd hand, and then more to insure after, and usually more to repair, thanks to those fancy fairings, wither having to take them off to get at anything or replace them when they get broke, rather damps the one thing 125's can do well!

I grew up in the 2-stroke days.... [Bisto Sigh!]... 125's could be moderately 'quick' then. Out the crate though they all had to be restrcted to 13bhp for Learner-Licences, so little twixt any of them, unless you started tuning them; which was rather easier than with 4-strokes; but just as futle, especially when, at 17, for the sake of wobbling round the block infront of a chap with a clip-board, you got a ride what you like licence straight away and could go jump on however much power your wallet would allow!

An engineer by proffession, it's frustrating that the last twenty five years have not been in pushing forwards the bounds of technology, but significantly only in lowering manufacturing costs. And the differece between the 1982 Honda CB125 Super-Dream and the 2007 CBR125 is a pretty good example!

My enthuiasm for the little CB125's then is an aquired one of middle age; In my teed I rode Yamaha TY's and DT's and a Kwak AR125 for the road. Little 4-stroke Twin, to my teen ideals was something of an anathma, all that complexity of cams and valves for no advantage! It was the bike your Dad chose for you! But with more mature eyes? It was actually de-tuned to meet the UK licence limits of 13bhp. Original 125 twin, and other market models of the 'Super-Dream' offered 17, as much as any of the two-strokes, even a lot of de-restrcted ones; And Honda had chucked all they had at the thing as far as making the 'best' flag-ship 125 they could, with a for-stroke engine, to keep the flag for four-bangers flying. In an era of 6v A/C direct (from generator) electrics and kick-starts; they gave the CB125 12v electrics and an e-start. It also got mult-link mono-shock rear suspension, like a modern 'big' sports bike, when most were still sporting twin shocks or simple cantalever's; also got mult piston front disc brake, when most still ran dums or simple single piston discs. Fact that 'most' of what were advanced headline features on that bike when new are now the accepted norm, and only recently shows just how 'advanced' it was for it's day.... and it still IS!

2007 CBR125? The engine is more advanced, but les powrful for it!... It boasts multi-valve cylinder head, though still only one cam-shaft, and just one cylinder, and later models got electronc fuel injection; almost entirely to meet tightened emission controls, as it s actually no more powerful than the 'restricted' air-cooled twin engine! Yet costs more to make. Hence the rest of the bike displays more advaces in cost cutting than 'performance enhancement'; Suspension for example returns to a simple cantilever arrangement, whilst brakes and chassis are all 'dumbed down' for production easement and lowest 'acceptable' quality level. And those sporty fairings? Which do little or nothig for performance, are significantly 'just' to improve perceived value i the show-room, and hide multitude of sins behind the panels where they would have to spend more money to keep it tidy!

Comparison is indicatve of the times the bikes were created; 125 Twn comes from an era when technology was exiting, and expected. CBR comes from an era where style rules over substance and cost over all... and YET manages to be a more expensve 'product' for it! A soulless creation of the accountants and marketing men...[bisto-sgh]

For what it IS?!? well, I wll confess to considering buyng one six years back when my O/H Snowie was still on L's, for her to get her licence on. For what they are, they aren't 'bad', they just aren't anything 'special', and the fancy plastc does not make them any more useful than the 2/3 the price CBF; just more expensive, to satisfy a sense of style and fashion.... which is fair eough, IF you accept that cost is a vanity, and doing no more for you.

For Snowie, a woman, more fickle about such things, that's important. And, for her, we could afford it, so why not? BUT, if you are scrapng the barel to save up for anything? If you are scraping the dregs for less knackered old dogs to keep you going? Well its still your money and your choce, BUT.... like I said, fastest bike is always the one that works! And better bike is the one that does more and gves less grief or hassle and leaves more cash in your wallet for going places!

So 'Bad' Idea? Well, maybe not. But certainly not 'the best' idea. For where you are at; close enough on that by the time you have aved up for a better bike, you are within spit of dong A2 tests? THAT has to be worth holdng out and maybe making a few sacrafices for, surely?

By the time you have saved up to buy a 'better' 125, you could chuck that cash at converting your A1 to A2, and instead of buying a 'slow' 125 that looks like it should go fast, you could buy a properly 'fast' bike of any style you like from Ninja 250, through SV650, and plenty in between; WHICH needn't be particularly more expensive to run or look after, and at least has the performance it pretends to for it.

Alternatively; 125's biggest asset s 'cheaps', so scrappng aspirations for bigger, better, faster, more; prioratising low cost functionality, plenty of 'better' 125's that are cheaper to buy and to insure and run; that would do that job better than a CBR125 that falls between two stools, being neither low cost commuter nor genuine sports bike.

But plenty of time to weigh things up as you save up; but that's how I would be looking at it; 'practically'. End of the day, you can have pretty much whatever you want, if you can afford it; you just cant have it ALL, you have to make compromises and sacrifices; and 'the best' is almost always the best 'COMPROMISE' for YOU, not the 'best' features, functions, performance or price, but all of them, on bag.

On which basis, the hugely compromised CBR has little to commend it and get it placed higher in the rankings than a YBR125, or an SV650, or a CB500... compromises it begs on costs, on performance, are huge, bonus it offers for 'style', is of very very mutable merit, and to my mind, ultimately no where near enough to accept the other compromises... but as said, its your cash, your conscience. You have to find the 'best compromise' for YOU.
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Georgek591
Derestricted Danger



Joined: 02 Jan 2017
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PostPosted: 18:49 - 05 Jan 2017    Post subject: Reply with quote

Putting my current bike aside. If you were to recommend someone a 125 based on performance, looks, reliability and cost what would be your top 3 recommendations?
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Teflon-Mike
tl;dr



Joined: 01 Jun 2010
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PostPosted: 00:04 - 06 Jan 2017    Post subject: Reply with quote

YBR125
YBR125
CBF125

Looks wouldn't come into it.. WHO bludy looks? "Sorry Mate I didn't See You" is first thing they say when they knock you off! Ad thems the ones who SHOULD be looking!

Performace? Lol!With a limit of 15bhp on anything that you can ride on L's/A1 none of them have any! Small difference in the lack of, between any is negligible.. fun factor any offer is huge regardless.

In the last decade, two of the bikes that have put biggest grins on my face have book-marked the poles of tiddling!

First was a '92 round-lamp 7-speed Gagiva Mto, which is a single minded 'thrasher' wasted on learners! Screaming two stroke power band and THE most unforgiving nature of almost any motorcycle I have ridden in an awful long time; it has so little power it crucifies you for getting anything 'wrong'!! For an experienced rider like me, its an absolute hoot, begging to be thrashed to the ragged edge, just' to make the sort of progress I would on the 750 in 'auto-pilot' pondering my shopping list! Very very demanding to ride, to get the best from it, and very rewarding, BUT not a particularly wonderful machine for a newby to cut thier teeth on, and more expensive to insure and maintain than my 750, it's just NOT 'cheap' or economical, or in any way every day practical; its a single minded thing for a sunny sunday 'scratch' not an every day rider.

Other end of the scale, and astounding me by how much I perversely liked it was O/H's AJS 125 cruiser-thing!!!! My opinion of Chinky 125's is that if you know enough to live with one, you probably know enough not to buy one! But, err nibs was daft enough. I actually met her asking about where she could get a chain & sprocket set for it, frustrated by 'Stupid woman' attitude from the parts pervayors!!! Bit of know-how, walking into local breakers waving the old chain at the cut off clad crew to count links sorted that out, and for 400 she had remarkably reliable daily wheels, that seemed to shun filling stations, and started on the button each and every.

'Performance' was laughable; it would just about do 55mph if you chucked it off a cliff! Whlst it's 'handling' was about as inspiring as a Liberal government! BUT, she used it to trundle to a coulpe of rally's.. and it got there... and not long behind the big bikes! And we even toddled out on it, 2-up, hunting for something a bit more 'test friendly' for her; and I had a hoot round Derbyshire, trying to keep the speed up wthout her hitting me round the crash-hat deckng its pegs!!!

A 125, and worse, a cruiser, it did little to inspire.. but, it just 'did', and did t damn cheaply and for remarkably little hassle.. but, I suspect large chunk of 'luck' went into that one.

Thing is, the 'fun' isn't in the bike, how fast it can go or how fast t looks like it could go, or how loud it is when it goes; the 'Fun' is in getting out on the damn thing and putting it to use; an stuck at home mourning not havng the cash to stick petrol in it ent fun. Havig a bike that dont work, and needs fixing ent fun. Havig a bike that promices performance you cant use because the tyres are knackered or the chain on ts last legs or the brakes are a t 'iffy' aint fun.

FUN is in having a bike that just works, and works as well as it should, and lets you get out there and put it to use....

And here we reach a dichotamy; TOY or TRANSPORT?

My bikes don't have to earn their keep as every day get to work, earn my crust transport; they are toys. I started off as a School-Boy in competition trials, where it was all for fun, and still is. I actually learned to drive so I could haul the comper to events rather than have to beg lifts! And I still find trials the most rewarding pursuit; may be slow, but its demanding, its engaging, it requires an awful lot of discipline, precision and thought; Road-Racng, I very quickly found 'boring' tearing around and around in circles, there was little challenge, but that is what so many aspire to and try and emulate, looking for adrenaline kicks on the public road, WHICH isn't the pace to get'em!!! To me, road ridng is about going places, seeing stuff; exploring new places, NOT seeing the same old bit of road in an increasingly fuzzy speed blur!

So as a 'toy' road bikes have a place... sort of along side camper vans, rather than Ferraris! , as a means t and end, NOT an end in themselves... for that, take it to the track, where points mean prizes not penalties!

As transport then; you have daily 'chore' get to work transport, and work isn;t supposed to be 'fun' so getting there tends to have little, before you look around at the through of half awake zombies around you gnashing on their steering wheels, taking o notice of you, as they ride over your feet or send you into the gutter watching only the two tail lights of the car in front of them! 'Inspiring' is not a quality that is particularly relevant or important in that environment! Only requirement that's particularly 'useful' is cheap and reliable, and less cost/hassle than the bus!

Which brings us back to the Yamaha YBR125, which is the bench-mark to judge all 125's by.
New in the show rooms they are about 2500, which is neither 'cheap' nor overly expensive. They are good value, and easy to live with. Insurace prices are sensile; running costs are sensble, and if you have a problem, or need a part they are well known ad usually fairly easy to deal with. All round they represent a pretty optimal compromise for costs, performace, useability ad liveability. They aint nspirng, but they get the job done, and dont make too much work for you whilst they are about it.

The 'premium' 125's like the CBR or YZF, are laughlably 'less' slow. They are laughably less ugly. Are o easier to ride; o easer to live with, dont hold thier value any better; they just cost more, for that minuscule added extra top speed, in favorable conditions you might get it, and the more pretentious 'styling'...

I actually think that a YBR 'looks' better than a YZF or CBR or Veradaro or CRF or whatever Yamaha hare calling their 125 trailie at the moment. That's not to say I think it looks good... but t IS unpretentious; it looks like what it is; an unpretentious utilitarian and 'useful' 125, that's not pretending to be anything it isn't, just getting on with the job.... and probably doing t damn well, and giving ts owner just as many if not more to smile about along the way.

Low rent Chinks, haven't, n the last 20 years got any better as so many hoped, but they haven't gone away either, and we've found ways to live with them. They still usually don't even offer the lack of performance of the Japanese utility models, but can delver 'enough' to be useful. They dont ted to have the reliability of a YAm or Honda either, so you do have to know one end of a spanner from the other and be prepared to get your hands dirty on a regular basis, and 'problems' can be harder to sort wthout off the peg solutions of support for them. New bike depreciation on them is still horrifyng which makes their 'cheaps' rather questionable on an all in cost per mile equation; but 2n hand, you can get a lot of use from one for your cash, IF you are prepared for the hassle factor and getting your hands dirty... though I would rather put that time and effort into an old Jap more likely to be worth it and at least have that little extra oomph for it.

Like I said, we did ponder a CBR125 for Snowie six years ago; BUT, favorite was the CBF whch is much of a much fag-paper close to the YBR... Absolutely NOT worth the extra money to me... but 'woman's' shoes syndrome'... they just KNOW they will pinch thier toes and they wont be able to wear them all night BUT 'Pweddy" wins every time, and the ear ache isn't worth the argument!

In the end, after making mutterings about wanting 'a project' and spurning all attempts to d a 'big bike' for when she passed her tests, and buy a CBF to get that done on... she wanted to bag it all up on one and did the 'The Pup'.. which is aother story, and still significantly not devoid of more woman's shoes syndrome... but still.

If No4 son came to me waving HP agreements he wanted me to countersign on a Lexmoto, or asking me to drive him round a mates to look at an old CG he rckoned he could 'fix up easy'... Absolutely O question, I would be draggng him over to D-C and foisting a three or four year old YBR125 on him, IF for o ther reason, that I KNOW I would be the muggins left holding the spanners and being moaned at for the price of the parts on anything else, and I have far ore worthy and interesting projects to occupy my mechanical masochism, than carry on where they left off with BMX's they treated as toys, they were, before high-school.....

For ALL the Snowies Cruiser thing bucked the trend, I have far too many broken and bent Chinky 125s wheeled into my front garden by over optistic tenagers hoping for a miricle to 'buy in' to that sort of hassle.

For all the Mito made me grin... as an ocassional Sunday morning 'toy' bike, costs just didn't justify the fun it offered; Cickey I can do a whole season's trials competition. 'all in' including the petrol to drag the comper to events JUST for what that thing cost to insure for the road!

Which brings us full circle, and Toy or Transport, and for the road, transport wins and can earn its keep; gettig you to and from to earn your cust, AND offer a bit of camper-van fun heading off explorng, seeing places, dong stuff, and the 'fun' is in your attitude not your machine or the way you think it looks....

So YBR YBR YBR.. which does what it says on the box, without unnecessary costs, or hassles or pretense. Its a REAL bike, built to be ridden; to get you places least fuss, most fun. Its not cheap tat, trying to kid anyone it's as good as, or expense bling costume jewelry tryng to kid you its something its not. It just is. Plain, simple, and honest, and just gets the job done.

Its a very very hard 'package' to better... and most alternatives, just wont; for any small 'more' they offer, there will almost certainly be a much larger sacrifice to make for it.

Just as an idea, on that toy or transport dichotamy... I said I started out in School-boy trials; I wasn't a spoiled brat sponsored by Daddy; I worked every scratty part time or odd job to save up to buy and run my bike before I was 16, and begged favors from whoever I could attending the meets I wanted to get to, to get to them.... and to get around? I took the bus! THAT was my compromise. Bike was all toy and no transport. But 'fun' I got was of a different sort and a different order to mates sat outside the chippy on their fizzies bragging about scrapng pedals and blowing pistons! I so often shared the bus with when their precious ride' weren't working!

How much do you 'need' the transport? How much do you WANT the fun? And what sacrifices are you prepared to make t max the compromise to your favour?
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'
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CBRMAN94
Nitrous Nuisance



Joined: 10 Jun 2013
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PostPosted: 20:18 - 11 Jan 2017    Post subject: Reply with quote

Georgek591 wrote:
Also I think the rear brake was replaced after the accident as there's a cable and no little hydraulic brake fluid box.


Can we have a photo? Genuinely interested in how it's been done Smile
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