Chainsaws,weedwhackers,snow blowers...oh my!



happycheapskate

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I saw a bike with a snow blower engine on youtube, that used a chain turned by motor, idler pulley with spring tensioner, and a bmx wheel mated to a 26" wheel by little tabs, like the old 1900's motorcycles. If you put rubber tool coating on the inside of the bmx rim, or mated 2 narrow BMX rims with rivets, you could have almost 1/1 "cog" size. Cheap bmx chains should run a long time on it without stretching being a problem.
 

happycheapskate

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Wow, that is just awesome.

Story starts the same....guy drops off a bicycle & a chainsaw.....
(note; we did this build totally, with materials on hand.)

here is where we started. http://www.motoredbikes.com/showpost.php?p=76719&postcount=36

here's where we are now..... 3 chains....2 jackshafts between the 36cc engine and the rear wheel. total gear reduction 24.9:1

this bike pulls well from a stop & pulls away from my fastest happytime (Rusty)

here's some pics....comments welcomed!
 

Jeco

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I am glad I've found this thread, I am planning to put a weed whacker or chainsaw on a foldable bike I have here.
 
5

5-7HEAVEN

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I am glad I've found this thread, I am planning to put a weed whacker or chainsaw on a foldable bike I have here.
Hey Jeco. Be careful how much power you install onto your folder. My first MB was 1.6hp Subaru engine w/friction drive. Perfect, w/top speed 27mph. The bike went much faster w/2.2hp Mitsubishi engine and Staton chain drive. HOWEVER, it became too unstable and squirrelly. i removed the engine and gave away the bike.:bowdown:

Be careful in your choice of engine/bike combination.
 

Jeco

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Thanks for the advise 5-7Heaven!

I am not sure how much power on the 26cc homelite weed trimmer or on the 25cc Ozito chainsaw I am eyeing on.

Some more queries 5-7heaven...

Will these engine do? Which one has better torque?
Will this be good on friction or chain drive setup? I might use a sprocket from an HT or a bicycle chainring if applicable.

I will make sure the bike is good enough to motorize.

Thanks again!
 
5

5-7HEAVEN

Guest
Thanks for the advise 5-7Heaven!

I am not sure how much power on the 26cc homelite weed trimmer or on the 25cc Ozito chainsaw I am eyeing on.

Some more queries 5-7heaven...

Will these engine do? Which one has better torque?
Will this be good on friction or chain drive setup? I might use a sprocket from an HT or a bicycle chainring if applicable.

I will make sure the bike is good enough to motorize.

Thanks again!

I wouldn't know about these engines, but modt weedwhackers end up on friction drive, bump start. Chain drive with clutch would be nice.

Contact deacon on the other forum. He is most knowledgeable on DIY-weedwhackers.:unsure:
 

happycheapskate

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Most weedeaters are designed to be cheap, lightweight implements that can turn a 6" string hard enough to beat down weeds in the fence corners. Anything under 50cc is probably going to suck, but may be able to hold 20mph if you pedal first.
 

happycheapskate

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Depends on the make, I guess. I expect a chainsaw will generally have higher compression, higher RPM range, and probably gobs of torque. The problem will be how to fit it to a bicycle. Its been done, a variety of ways, so I would guess that is where I'd start if I wanted to use such a motor.

Chainsaws generally have a small notched wheel running directly on the crankshaft, attached by a flatted, threaded shaft, with a locknut. You will have to use something else to either turn a standard bicycle chain, or mount some type of roller for use as a friction drive.

I have seen Youtube videos where users have welded a modified bicycle cassette sprocket to the clutch, and used the chainsaw, mounted on a cheap bicycle rack, to turn either a Happytime sprocket, or the front crankset. Dangerous territory there!

This video shows a chainsaw motor driving the tire with the actual clutch! http://www.youtube.com/watch?v=cqu3vG-DrfY&feature=related

If you can order a Bike Motor Parts rack drive, you can use dozens of standard auger, 2 cycle air pump/water pump engines, pocketbike engines, etc, but I haven't heard of a chainsaw engine that has the same mount holes and clutch.
www.bikemotorparts.com

http://www.youtube.com/watch?v=zeofT8lUmAY
Home made friction drive from junkyard chainsaw. Looks like the standard BMX axle peg for a roller. This would work well, but eventually wear the bearings, and if the nut on the peg loosens, the axle peg can be thrown violently. "Check your nuts!"
 
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