Still thinking on this one havent figured out a good solution yet. thinking maybe move the peddles back toward the seat like behind the engine. dunno though. it would be hard to peddle that way.
west coast choppers with a briggs in the works
- Thread starter jcchappy
- Start date
Got some more done this morning. Been trying to stuff a 318 in a dakota so havent had much time but it rained this morning. I took a mountain bike rear hub apart. took the little "dogs" that make it a one way sproket out now its an idler show in first few pics. I also found an intake to mod and carb to use. I think I have it on the downhill slide now.
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The way the idler works
The mountain bike rear sproket and hub/axle are welded to a plate then welded to a heavy duty hinge. The hinge has a hole cut through it and a nut welded on the hole then a bolt is screwed through the nut through the hole and pushes on the frame which opens the hinge and tightens the peddle chain. I had to put an idler in under the back part of the frame so the chain would not rub the frame.
The intake
The intake is from a 110 chinese bike I will cut and splice it back together so I will have a normal motorcycle type intake carb and cone breather instead of the briggs type carbs.
I know this is a lot of work just to retain use of peddles but I want an actual bicycle with a briggs engine on it not just a scooter. Not that i am going to peddle it or anything.It is just a challenge I set for myself.
The mountain bike rear sproket and hub/axle are welded to a plate then welded to a heavy duty hinge. The hinge has a hole cut through it and a nut welded on the hole then a bolt is screwed through the nut through the hole and pushes on the frame which opens the hinge and tightens the peddle chain. I had to put an idler in under the back part of the frame so the chain would not rub the frame.
The intake
The intake is from a 110 chinese bike I will cut and splice it back together so I will have a normal motorcycle type intake carb and cone breather instead of the briggs type carbs.
I know this is a lot of work just to retain use of peddles but I want an actual bicycle with a briggs engine on it not just a scooter. Not that i am going to peddle it or anything.It is just a challenge I set for myself.
got some more done today. Still messing with the chain and stuff. Got the intake and carb mounted and started the exhaust what do ya'll think?
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hey , i like the way your exaust is looking , i sure hope you never slide off the front of the seat , talk about a meat grinder , youch , looks like its comming along pretty good though .
Rode it a little today! Under pedal power though. Just testing out my sprockets and stuff. Went through like 30 different sprocket and chain -adjuster combos. finally got a system working somewhat. Like I really care about pedals. I think I will get some tank of sorts on there this weekend pour some oil in it and hook up the new carb and try out the engine then get ready for tearing the engine down for cleaning and power goodies. I have been going to cart racing sites and most people say the main thing to do is upgrade the oil slinger tab in the engine.
yes, change the oil slinger in there for max lube, though it may not be needed actually unless other mods are done to engine. doing go-cart racing when younger we had modified slingers in motor.
I just rode it with the engine. Very unimpressed. I think the jetting may still be of on the motorcycle carb messed with it some and it got better but... I will mess with it some more tomorrow if it doesnt get any better I AM PUTTING THE 5 hp briggs in it it will still fit and all my exhaust and intake even the clutch will swap over. it just doesnt have recoil start but no biggy one less thing to break out on the road. maybe the gearing is just off I dunno but that is the biggest rear gear I can find. I just has no pulling power hardly. that clutch chain and gear was on a mini bike on it had plenty of power but the engine was a 6 hp tecumpse and small rear wheel.
your running something like 7 or 8 to 1 , with the 3hp your not going to have much bottom end , but once you get going it will go fast , thats a much bigger tire than a mini bike .
this is the vid i made of mine , i,m geared at 16 to 1 , i get about 20mph out of it , at 16 to 1 , theres lots of power , i,m going to experiment with different ratios sometime , i will use this motor on my next fully custom built bike . i,m designing a 3speed transmish , i hope to make it 16-1 , 12-1 , 8-1 . the vid will give you an idea of the takeoff i,m getting at 16-1 .
YouTube - motorized west coast choppers bicycle
don,t give up , i wanna see this thing running
this is the vid i made of mine , i,m geared at 16 to 1 , i get about 20mph out of it , at 16 to 1 , theres lots of power , i,m going to experiment with different ratios sometime , i will use this motor on my next fully custom built bike . i,m designing a 3speed transmish , i hope to make it 16-1 , 12-1 , 8-1 . the vid will give you an idea of the takeoff i,m getting at 16-1 .
YouTube - motorized west coast choppers bicycle
don,t give up , i wanna see this thing running
Well I gave up, then tried it again. Ruined my chain. It popped off and wadded up around the wheel not going fast so no big deal no wreck or anything. I had a good idea i think though. Use a regular belt pulley on the engine put a 16" or even anothe 20" rim attached to the rear 20 " rim on the back wheel and belt drive it. that will give me what 20 to 1 ratio or so. then that sucker should pull me easily. My china girl bike has a 60 something cc engine (80cc) but it has a gear reduction built into the engine. that is the difference and my buddy mike was saying the little Red Bat China girls have like 5 to 6 hp so... but I think the lower gear ration will fix this thing and a regular back tire. the tire is too wide I had to use 2 rag joints stacked together to get it to clear the tire and still had to cock the wheel to clear it enough.
1 good thing I guess I got the engine running really good. Lapped the valves and have a custom carb and exhaust setup for it.
