A few weeks ago, a mate of mine found an old folding bike dumped in the bush near his work.. After some beers we decided upon a plan for it, involving a cheap mini-moto knockoff, and his recently purchased welder which we were both eager for an excuse to use.
Take one "Universal" folding shopper bike
Weld the "Folding" mechanism up, and swap the back wheel:
Cobble the engine in the middle (and buy £25 worth of timing chain from the most arrogant man in nottinghamshire to use as a drive chain)
And you're off!
For about 10 minutes - Before fitting it, we stripped the engine down, and I managed to snap about 1.5cm off the end of a piston ring like a clumsy idiot - not realising they had a pin in the ring seat to stop them rotating round and covering the exhaust port, so had the ring covering this while trying to shove it up the barrel (quite gently!)
Anyway, after this upset, we put it back together with nearly a full pair of rings expecting "badness", but after some drama (I turned it over with no carb on, it somehow started up off the fumes in the crankcase and span up to about 3000000000rpm and fired a big flame out of the exhaust, with no way to stop it!) it fired up and ran great for about 10 minutes of (ab)use, where it was pretty deadly and wanted to fire you off the back constantly. All of a sudden it made an awful clanking noise so I cut it off quick, and it wouldn't turn over anymore. We both pretty much knew what was up!.
We got it home, stripped the barrell off and the dodgy ring had shattered, wedged in the exhaust port and knocked a chunk off the piston
A quick look on ebay found a shop about 15 miles away selling piston kits for a fiver, so after tidying the bore up with some 800 grit, our enthusiasm was refreshed
We'd left the original front wheel on mainly because one of the bearings in the little wheel had collapsed, but the shop also had bearings, so we decided to put the little wheel on the front too, which meant spreading the forks quite a lot.
After some enthusiastic bending, the forks cracked at the CROWN, so we decided to kill two birds with one stone and weld a bridge piece in, to mount the front brake on and to reinforce the forks again. We're left with this:
The eagle eye'd will notice it is missing the exhaust... the very eagle eyed will notice the aerosol cap instead of a barrel - With any luck she'll be moving under her own power tomorrow after jon collects the new piston and bearing, just in time for RRG!
Take one "Universal" folding shopper bike
Weld the "Folding" mechanism up, and swap the back wheel:
Cobble the engine in the middle (and buy £25 worth of timing chain from the most arrogant man in nottinghamshire to use as a drive chain)
And you're off!
For about 10 minutes - Before fitting it, we stripped the engine down, and I managed to snap about 1.5cm off the end of a piston ring like a clumsy idiot - not realising they had a pin in the ring seat to stop them rotating round and covering the exhaust port, so had the ring covering this while trying to shove it up the barrel (quite gently!)
Anyway, after this upset, we put it back together with nearly a full pair of rings expecting "badness", but after some drama (I turned it over with no carb on, it somehow started up off the fumes in the crankcase and span up to about 3000000000rpm and fired a big flame out of the exhaust, with no way to stop it!) it fired up and ran great for about 10 minutes of (ab)use, where it was pretty deadly and wanted to fire you off the back constantly. All of a sudden it made an awful clanking noise so I cut it off quick, and it wouldn't turn over anymore. We both pretty much knew what was up!.
We got it home, stripped the barrell off and the dodgy ring had shattered, wedged in the exhaust port and knocked a chunk off the piston
A quick look on ebay found a shop about 15 miles away selling piston kits for a fiver, so after tidying the bore up with some 800 grit, our enthusiasm was refreshed
We'd left the original front wheel on mainly because one of the bearings in the little wheel had collapsed, but the shop also had bearings, so we decided to put the little wheel on the front too, which meant spreading the forks quite a lot.
After some enthusiastic bending, the forks cracked at the CROWN, so we decided to kill two birds with one stone and weld a bridge piece in, to mount the front brake on and to reinforce the forks again. We're left with this:
The eagle eye'd will notice it is missing the exhaust... the very eagle eyed will notice the aerosol cap instead of a barrel - With any luck she'll be moving under her own power tomorrow after jon collects the new piston and bearing, just in time for RRG!
