Newbie Questions for weed eater engine

[Plush]

Hey guys

I'm planning to install a weedcutter engine but not the friction driven type for my bike. but then i wondered how do you guys modify the hubs to have a sprocket on the other side of the hub? can you give any tips or links on how you guys do that? thanks alot!

 

[pocdragon]

seeing how that was your first post, i must insist upon using a friction setup, they are easy to build, cheap to maintain, and dont use sketchy chains

the only con for friction drive is when it gets wet you lose all power unless you have a sophisticated roller

i got a 25cc weedwacker bike to do 30.4mph
faster than most stock happy time bikes with more than double the engine displacement


if you must insist on chain sprocket drive then your going to need to fix a clutch and sprocket to your engine, making it true and straight, as for the rear wheel your going to use some sort of rag-joint clamp on style gear, then mount the engine accordingly either above the wheel, or in the frame
if your using somthing small for an engine you can prolly use pocket bike chain and sprockets

 

[Plush]

thank you so much for the reply! Question, is it hard to install a clutch and sprocket n my weedcutter? thanks again pocdragon!

 

[irishpowerjunkie]

hey dont know if this may work for you but my system uses a honda strimmer engine with the original clutch modified by getting a sprocket from gearbox of motorbike and welding it onto the shfat coming off centre where the shaft of the strimmer went onto it and also for safety bolting through the holes in the sprocket and onto the inner side of the clutch and on the flywheel creating a plate with a bar coming off centre to bolt original clutch back onto engine with the clutch shoes above the plate using original clutch shoe holes

 

[a_dam]

irishpowerjunkie,

You're using the string trimmer's clutch? How long has that system been holding up? Even with a top-dollar trimmer, I can't imagine the clutch driving a bike for very long.

Plush,

I've only done friction drive, myself. One of these days I want to try a weed whacker, chain drive, skinny tire ten-speed. (I have quite a few 1970s Schwinn continentals and varsities & parts)

Their narrow frames are not ideal for chain drives. But I know how I would mount a rear sprocket. The hubs have big ol' flanges; just under 3 inches diameter. Looks like they could be drilled out for bigger gauge spokes. And there are 8 holes already in the flanges. These are the old Made in France "Schwinn Approved" parts.

In the picture you can see a 1/4 x 20 bolt easily passing through one hole. Below it a 5/16 bolt almost goes through - two strokes of a round file away from fitting.

So if you see an old schwinn being tossed, at least grab the hubs. They would be good for making a jackshaft, too. I also used one for the tailstock of a homemade wood lathe.