Add a 5th gear or gearbox upgrade.

[ilonasn]

Hi

I have a Malaguti Motard X3M 125cc from about 2010.
The front sprocket has 13 teeth and the rear sprocket has 51 teeth.
Hills are never a problem now but on straight roads, the bike is maxed out in 4th gear and another gear would be the ultimate driving experience , or is there an upgrade available , maybe an XT one would fit since it is a Yamaha engine.

Cheers,

ilona

[P.]

You 'should' be able to drop an XT125 engine in there, but depending on whether thats a carb or EFI bike you have there.

If carb, then engine + ancillaries + carb + airbox will get you all gears possible.

[Howling Terror]

How heavy are you?
Is your chin touching the tank?
Is the chain oiled?
Is the gearing standard....It'll be the best compromise for most people eg a small light rider may eek a bit more topspeed with taller gearing.

1) Buy a lighter 125cc bike with a fairing.
2) Buy a bike with a bigger engine.
____________________
Diabolical homemade music Bandcamp and Soundcloud
Singer songwriter, Artist and allround good bloke Listen to Andrew Susan Johnston here
The Harry Turner Project

[ilonasn]

Hi

I am heavy, maybe 70kg.
It already has an engine with a carb and is air cooled.
I don't want to buy another 125cc and if there is a way to either upgrade the gearbox or add another gear to the gear shaft than that would be more than amazing; but where would I find out about such details since googling it has not been successful at all.

ilona

[P.]

no, thats fucking retarded.

Replace the engine with the XT one.

[MarJay]

You just buy the extra gear, then place it on the side of the engine, then hit it with a hammer until it goes into the gearbox.

Sadly I was being facetious, it doesn't work like that.

The cases are designed for a specific set of gears which sit on shafts inside the gearbox. With a four speed gearbox you have two shafts with two gears apiece. In order to add another gear you would need to add another shaft, and there isn't any space inside the box for that.

The only way to do it is to swap the entire lump as others have said, or sell the bike and buy one with a five or six speed gearbox.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[-]

[Pete.]

[Rogerborg]

[ilonasn]

Hi

Thanks a lot for the hammer it into place option, might need to.

I love the front/back gear ratio as it is. Supposedly, some Yamaha engine/gearbox can be upgraded to 150cc. It's also possible to add gears if this was planned by the manufacturer from the beginning as an alternative but I still need to look into it - keep you posted.

ilona

[Teflon-Mike]

Basic primary laws of fizzix.. power=rate of work done, work done is force times distance, so power is force times speed.

Gears. Rotary levers. They can magnify force for a proportional reduction in speed, or increase speed for a proportional reduction in force.

You have a 10bhp, 4-stroke 125, dirt-bike with road-tyres... relatively speaking its tall and wide, and spreads you, the rider out like a human parachute when riding to increase the frontal area drag acts on.

With a finite amount of power, it isn't going to go any quicker, no matter how many gears you got or how you mess with the ratios.... the 'problem' isn't that you dont have enough gears to pick from, its that you dont have any more power.

Raise the gearing; use 14-52 combination or 12-48 combination, it will NOT defy the laws of phisics and suddenly let the bike top out at 120mph... because you still have the same amount of power... it will go just as slowly as before.

All you MIGHT achieve is to shift the top-out point an MPH or so either way; with lower gearing you will reach revs with more power to spare than is needed to reach max speed and so cant go no faster, or you will reach a speed where the resistance force is higher than you have power to over-come, and you'll top-out before you completely run out of power, but be unable to go faster, and maybe get at the engine revs you have a bit more, because the resistance force is always more than the driving force.

With taller gears, you might be able to go a tad quicker... down hill..... where the potential energy of being at the top of a hill, adds to the power the engine may make....

But back to square one..... power is force times speed.... you don't need more gears, you need more POWER!

Again... You have a 10bhp, 4-stroke 125, dirt-bike with road-tyres... relatively speaking its tall and wide, and spreads you, the rider out like a human parachute when riding to increase the frontal area drag acts on.

You want it to go faster on the flat... you need more power or less drag..... that means a bike with a smaller frontal area and pointy fairings... and oooh... with just 10bhp it STILL wont go much if any faster.... look at the specs... so you still need more power....

A 125cc four-stroke single, at BEST, might make oooh, all of 17bhp...... eg YZF-R125.... water-cooled, double-over-head-cams, four valves, fuel injected... and a lot of expensive tuning goodies and work chucked in to get it... briefly....for as long as the cylinder head gasket dont go pop......

Probably the most powerful air-cooled, two-valve 125cc single was the 1973 Honda CB125 motor, that the XL lumps were later based on... managed a heady 13bhp.. and was successively detuned year on year by the factory as it had a habbit of eating its own cam-shafts.

Doubled or quadrupled up, to make a twin or four cylinder engine..... two-valve air cooled engines topped out at around 100bhp per litre.... about 0,1bhp per cc... that's multiplies out to.... oooh.. about 12.5bhp from a 125cc engine.....

Think you can do better than Honda, Suziki, Kawasaki, Yamaha, Ducatti or BMW's enormouse R&D departments? Go for it!!!!

You will NEVER manage to get much more than 13bhp from that engine, no matter how much you do to it... and without that extra power, it will not go any faster on the flat regardless of how you mess with gears.

As has been said... you want more than what you got... buy another bike.... and even then, another 125 will probably still not be much if any different, all of them having the same 'problem' that limited to just 125cc they are also limited to how much power they may make, and you are in a world of slow, where even the fastest of the fast, two-stroke 125's, that might just top a ton, are only barely as 'fast' as thirty year old 250 commuter bikes, let alone anything bigger, newer or more sporty.

What you have is what, eight years old; and no spring chicken... and fact you say its from 'about' 2010.. does make me wonder how legit it is, and whether its even a road legal bike, not a probably stolen or scrapped field-bike... or you should know EXACTLY how old it is and when it was first registered for the road...... but just on age alone, its likely not making all the power or able to go as fast as it should, after almost a decade of learners fiddle fingers trying to 'fix' it....

Old track addage, before looking for more than standard, make sure you have all you have AS standard... and if that aint enough... rather than try re-invent the wheel, look for a different standard that gives you what you want......
____________________
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?'

[-]

[MarJay]

[P.]

The only way to keep your bike and increase gears is to add the XT engine to your frame.

[The Shaggy D.A.]

[ilonasn]

[MarJay]

According to Bikez.com the Malaguti X3M 125 has a 5 speed gearbox...
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[supZ]

[ilonasn]

Haha 🤣 Sorry, for the confusion but I did’t consider ‘Neutral’ a gear.[url][/url]

[MarJay]

[P.]

Other places state 5 also, your bikes fucked.

[supZ]

[WD Forte]