Front Drive Question

[happycheapskate]

I don't think small holes in the side of the rim will cause a problem. Since that surface will not be a braking surface, I am sure it will be ok. There is a small possibility of cracking or pulling through the rim, but if you keep the nuts tight, and the rim is quality stuff, it should work. I am happy about your build, because I wanted to make a 20" BMX or beach bike chopper with 20" rear wheel and an old edger motor, using that technique. I like the idea of a belt drive better than a chain drive.

 

[lowracer]

happycheapskate,
My very 1st MB built back when I was a kid used 20" rims & same rim to rim pulley system.
It had cheap steel rims that I had a welder spot weld together in multiple places. I am confident the JB Weld along with the 4 bolts will hold for the long haul.
I read alot of folks on here dont get many miles out of the Gates belted Gebe system before needing to replace their belts. I now have over 1000 miles on my MB & the V-Belt still looks brand new. I am hoping I'll never need to replace it. I havent ridden it in the rain & dont plan on it, so I dont know if there would be any slippage in wet conditions...
-lowracer-

 

[happycheapskate]

Thanks for the tip. Is the Gates belt the old style one (smooth) for GEBE stock systems? I heard they made a toothed kevlar belt now that has zero slippage.

 

[lowracer]

The belts are toothed on the GEBE system & dont slip but are real thin material & wear easily. The V-belt I use is the gatorback notched type (AX) & are designed to better go around real small pulley diameters (1.5" front pulley). If the belt is the weak link in the GEBE system only getting a few hundred miles between belt replacements, I would think the company should re-engineer that aspect of the system?

 

[happycheapskate]

Anything less than 1000mi for a belt on a bicycle motor at 40 or less mph, seems like pure waste, unless they're just giving them away almost. I'd be mad! The last chain I used on my grubee bike lasted about 400 miles, but it was pulled really tight and got derailed a bunch before I made a tensioner. I get KMC Z chains for $3 by mail order. This one is covered in heavy cheap auto grease and hasn't jumped yet.

I figured with a thrift store bike and an edger motor, an auto or lawn equipment belt should last for years if it isn't slipped a lot.


I saw a guy on youtube riding a snow-blower bike that used a 20" rim mated to a 26" rim, by about 8 steel tabs that were welded to each rim (centering the 20" on the left side of the 26" rim. He said it would do 45mph! On a huffy rigid beater!

 

[rodar y rodar]

ICE powered streamliners sound groovy, Lowracer! Thanks for the links. Just considering- if you don`t plan to acutally use the pedals, you could get even more streamlined than the "Big Boys" out at Battle Mountain and such by using pegs instead of cranks and pedals since you wouldn`t need to keep knee and foot room in the shell. Then again, you`d need an awfully big expense account to match the Varnas and Coslingers, etc. Any idea how much HP the 70 and 80 MPH riders are putting out? Think it could be more than a 35cc 4-cycle?

About your FWD moped- it looks like you already did a good job figuring it out, but the title immediately brought another build to mind. This guy had a much different take on it that you might be interrested in if you haven`t run into his site before:
http://www.outsideconnection.com/gallant/hpv/mred/

 

[lowracer]

Rodar y Rodar,
Lately I've been doing things on the cheap & wouldn't be looking to spend crazy money to go 'Battle Mountain tech'. Years ago I owned a Lightning F40 that I coroplasted where there was fabric & gained more speed. I could pedal it around town @ 30+mph & do 40mph pushing it for a short burst. Wind was another problem though & scary as cuss.
I got my pedal side of the MB geared such that I can aid the engine at top speed if need be (headwinds or just need more speed). Once the engine gets the additional help from the human & gets up into its higher RPM's it doesn't slow back down so fast once I stop pedalling. ICE Engine & Human Powered Hybrid at its best.
I wouldnt be interested in a MB without pedals. The whole reason I did this MB project was to still have a bicycle & not just a motorcycle. I also like being legal by keeping the engine & hp rating in the legal zone & stick to <50cc & <2hp.
-lowracer-

 

[rodar y rodar]

Lately I've been doing things on the cheap & wouldn't be looking to spend crazy money to go 'Battle Mountain tech'....
....I wouldnt be interested in a MB without pedals. The whole reason I did this MB project was to still have a bicycle & not just a motorcycle.

Understandable on all counts. I just misread your intentions due to your links.

 

[Harutz]

Lowracer, how has your rig held up?
I've been brewing a similar setup.

 

[motorbikemike45]

lowracer

I don't know where you have gotten your misinformation about rapid belt wear with the GEBE drive system. I suppose if the geared sheaves were wildly misaligned they could quickly wear out the edges of a belt, but I'd wager a fair amount the belt would jump off of sheaves THAT misaligned. I had several thousand miles on my GEBE drive bike before it was stolen and the wear on the original belt at that point was not measurable. The Kevlar reinforced geared belts in a GEBE system do not have an expected life in the hundreds of miles, as you stated, but in many thousands of miles. The GEBE system has some similarities to Harley-Davidson's geared belt drive and you can ask a hog pilot how his is holding up. Or ask one of the many GEBE fans how they like theirs.