Help!!! is it safe to chop behind the shocks without a loop

[simonizer]

Hello there!

I have a Honda CM125 C and I want to make a brat/bobber out of it just cheaply as its a 125, I want to cut just behind the shocks I don't have a welder so would just leave as is and fir seat, does anyone know if this is safe and would it effect M.O.T ?

Thanks

[stinkwheel]

A brat chopper doesn't usually have the subframe chopped off unless you're doing a shonky job. It has an elongated single seat unit and cowl attched...

...and a mudguard front and back. And an air filter. And if it has clip-ons, it also has rearsets.

Exhibit A: The CL350 off the Girl with the Dragon Tattoo.
https://2.bp.blogspot.com/-vKOBPSZ9L3U/TxSpF3IrqrI/AAAAAAAAJA4/Tiz6zFBjIps/s640/tumblr_lxcarzglYn1qheyozo1_500.jpg

EDIT: Anyway, not much to chop off a CM125 frame anyway and there isn't a closed loop originally. Just make sure you cut the subframe behind the gusset plates the shock mounts are on if you're going to do so. Have a think about how you're going to attach a numberplate, rear mudguard, flashers, tail light and seat unit BEFORE you start chopping lumps off your motorcycle.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[pdg]

I envisage yet another ruined frame ahead with a lash-up job done to try and make it look 'custom'...

My prognosis is that the frame will get chopped off, then the realisation will dawn that there is nowhere to hang all the stuff SW listed so it'll get bungied roughly somewhere, ending up winding itself around the back wheel.

Then, the OP will get fed up with a rooster tail of water going up under his helmet every time he goes out between August and May, so the bike will get scrapped/sold as "unfinished". Because, let's face it, it won't be finished anything like that CL.

I might be wrong, and the OP might do a decent job of it, but I think it's more likely I'm right. On this subject I would very much like to be wrong though, just once.

Over the years, I've had to fabricate and weld on new frame arses on something like 8 or 9 bikes that I got cheap as "fucked up unfinished projects", and done repairs to more that had been half cut off.
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Any and all advice given should not be followed - if you have to ask it means you don't know so get a man in to do it for you.

[simonizer]

Well I was going to leave the back mudguard or maybe shorten it a little and move up the lights/number plate, take off the indicators as its a 1985 bike or get a rear side light and number plate. I am new to this but trying to revise all I can , no chopping till I'm sure. don't really want that Café racer style seat, I just need as much advise as possible

[simonizer]

Well maybe I can just 're shape the seat that's on there and 're cover and leave it all as it is , I'm not some stupid kid I'm 40 years old , I will go to a local garage and get advice maybe they won't slate me, I have a brother in law who builds custom Harley sportsers ect but unfortunately we fell out over a bike he was over charging me for so now have to look into it myself ! Just thought I might get some help froma forum

[pdg]

If you feel I have slated you then, well, tough.

I've seen so many 'custom' bikes that are life-threatening lash-ups held together with blu-tack and tape that it's completely lost it's novelty.

It's pretty much accepted that the vast majority of 'projects' end up being sold as unfinished / for parts, or scrapped quietly while all the people who got enthusiastically told about it are looking the other way.

Good luck at a 'local garage'. If they know anything whatsoever about the structural integrity of a motorcycle frame you will be exceedingly lucky.

More likely they will just tell you to leave it alone because they don't know -- or -- they'll say "yeah mate, it'll be fine innit" without having any understanding of what is actually being proposed.


Oh, and your age means the sum total of fuck all by the way. I know 40, 50 and 60 year olds who are an absolute liability with anything even remotely spanner shaped and I was successfully rebuilding engines when I was 14.
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Any and all advice given should not be followed - if you have to ask it means you don't know so get a man in to do it for you.

[Rogerborg]

[Teflon-Mike]

"Standing" response my kids get to the 'opener' "Da-ad..." BEFORE they get to the 'silly question'.....
IF you have to ask.....
a) You don't need it
b) You cant afford it
c) you wouldn't understand anyway..
NOW what's the question? bearing i mind that the answer is almost certainly going to be 'NO' , and more the so, the more questions I have to ask to find out what you are REALLY after....

I spotted earlier post, and Rogers rapid response including instructions for a ply-wood perch.. and you're proposed 'solution' to contend with 'excess' indicator lead and connectors....

IF that is the level of attention to detail you are applying to this build, then PDG is bang on the mark, and you are just making even MORE drastic 'bodges' to fuck up an otherwise useful little bike and render it another pile of scrap, posing as a 'Special'.

My advice.... go make the ply-wood & stapled vinyl seat Roger suggested... DON'T fit it to the bike... don't do ANYTHING to the bike.. just go staple a bit of vinyl to a bit of ply or MDF....

Then find a bar stool or similar to prop it on, and try sitting on it..

THEN to emulate the effect of riding down a typical council maintained road, try doing 'bunny hops' on the bar stool....

(Ohh! The nostalgia! The idea takes me right back to my third year at secondary school, when our form room was one of the Domestic Science labs... I could by-hop a bar stool ALL registration long, I could!.. but I digress)

After half an hour on that pad, on the bar stool, ask your arse, if it thinks this is a good project to pursue..

'Cos I reckon that it wouldn't take many buny hops for me to remember I'm over 40, not 14, and I reckon your enthusiasm for that 'ugly old' saddle as fitted in Homatsu, will be rather greater, after a weeks worth of journeys on a plank, whatever the aesthetics!

Aesthetics WHICH I can almost guarantee, will NOT be improved by attaching scraps of wood to the bike with gaffer tape, making twisty wire connections and bundling excess wire up in loops to try and hide under the mudguard.... it will look EXACTLY like what it is, an untidy bodge of a bike, its owner cant be arsed to do 'properly'... and nothing 'custom' or 'special' in the slightest.

If you is gonna do it... DO IT PROPERLY, and, you KNOW how it SHOULD be done; neatly, tidily ad with the propper tools and techniques.... NOT bodges.....

So back to to;....... if you have to ask...
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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?'

[stinkwheel]

Further inspecting some pictures. Especially Rogers one in your other thread, confirms there is not much frame you could take off anyway.

I've taken the liberty of using rogers picture to show you the gusset plates i'm meaning coloured red. DO NOT cut into or forward of these.

You could probably do something with that fugly pressed steel pillion support/triangulation setup though.

So on attached line drawing. You could cut off that support through the red lines. You could then get a reasonably hefty bit of steel flat bar and bend a right angle on each end so it fits between the ends of the subframe (coloured blue). You could use that to attach mudguard brackets, plate holder, lights etc to.

For structural strength, get a bit of steel or alloy tubing that fits exactly between the ends of the subframe (I'd use as fat a piece of alloy as would fit in there) where the holes are and put a long bolt (ideally) or a piece of threaded bar* right through the lot (so through the hole in the subframe, through the hole in your piece of bent flatbar, through the tubing and back out the other side). A nut on each end to compress the whole lot together and it's a lot neater and structurally secure. You could even use domed nuts if they're going to be on display. Or pike nuts for 70's chop-ness.

Remember that by doing the above, you've just knackered the resale value of the bike because the frame has been modified and you can no-longer use a standard saddle.

As I've said before. People like to OWN modified bikes but they like to BUY totally standard ones.

*Threaded bar is not ideal but ios easy to work with. Not all threaded bar is created equal. Get grade 8,8 high tensile stuff, NOT the shite they sell in B&Q. Ebay is your friend for small quantities of steel and alloy stock.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.