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I Want A Belt Drive!!

HRDTLBRO

Turbo Monkey
Feb 4, 2004
1,161
0
Apt. 421
I've played around with an internal drive system and or an external belt drive utilzing the Rolhoff 14 speed internal hub. I've got numerous sketches, and am working on a CADD drawing for it. For the internal system i'm working on, it has zero chains, and uses small sprockets driven off the bottom bracket in the shell, fed to a shaft inside of the chainstay, then again using small sprockets by the hub. I doubt it would work, with small internal parts, hard to service/high mainenence. Just an idea to see what I could come up with.
 

zedro

Turbo Monkey
Sep 14, 2001
4,144
1
at the end of the longest line
maybe because an exposed belt drive + dirt and small debris = broken belts and damaged cogs. Might be neat for strictly urban, but then again, what would be the point?

wait, why arent you doing it for SS bikes?
 
Apr 25, 2004
49
0
NOVA
Maybe a year ago I remember hearing of/seeing an ad for belt-driven SS mountain bikes. I believe it was Jericho putting them out.... Then again I can't remember what I ate for breakfast yesterday so I could be totally off... I suppose it's worth checkin out though.
 

Fulton

Monkey
Nov 9, 2001
825
0
Originally posted by seventyohfive
Maybe a year ago I remember hearing of/seeing an ad for belt-driven SS mountain bikes. I believe it was Jericho putting them out.... Then again I can't remember what I ate for breakfast yesterday so I could be totally off... I suppose it's worth checkin out though.
ya, it was called the red october. they scrapped the idea becuse they couldn't find a belt material/tooth profile that wouldn't skip.
 

Fulton

Monkey
Nov 9, 2001
825
0
Originally posted by dhtahoe
Two words... Gilmer belt!!! It WILL work.
only problem with that, is how would you install it? Most frames, including all traditional diamond shaped frames require you to break the chain to install it...........
 

Espen

Monkey
Nov 25, 2001
345
0
Tigerstaden, Norway
Thats a good point! I remember the Jerico too, but dont remember if they did something special to get the belt on.

.....of cource, all the 4 bar ss bikes will accept a timing belts;)


e
 

Curb Hucker

I am an idiot
Feb 4, 2004
3,661
0
Sleeping in my Kenworth
that jerico (sp) proto had you slipt the frame instead of the belt. There was one of those threaded couplers right above the dropout, and you unscrewed it , flexed the stay out a bit and shoved the belt in
 
E

endtroducing

Guest
sideways and i had a many hour discussion about this a few months back. the possibilities are very interesting.
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
search the archives

Plenty of info on this subject in there.

Belts are incredibly succeptible to damage by debris, so an off-road system would have to be sealed. This means enclosed casings, seals, etc... As you can imagin this adds weigt and friction. Belts can be very efficient for high RPM use, but for low RPM high torque use, they are seldom the most efficient or longest lasting alternatives.

dw
 

binary visions

The voice of reason
Jun 13, 2002
22,102
1,153
NC
So, why would belts be significantly better for this use than a chain? Pardon my ignorance, but I simply don't get it.
 

HTFR

Monkey
Aug 20, 2002
413
0
Chelsea, Quebek
Originally posted by Jm_
all I want is a shaft...dammit. Wait a minute....
its been done i saw it in DIRT. some trials guys build one. looked kinda cool.

as for the belt idea. i think that there is a reason for using a chain.
1. look at the size of the "cogs" on the belt driven bikes. they look heave dont they?
2. you have yo have a "brake" in your frame.
3. mud and stuff gettting jammed uner the belt.
4.chains really are not that heavy, and belts arn't all that light ether.



IMO rule of thumb do as moto X does. :devil: :D
 

fonseca

Monkey
May 2, 2002
292
0
Virginia
Belt drives are actually extremely inefficient for bike use. Nowhere close to chains. Same for driveshafts, although they have potential.
 

fonseca

Monkey
May 2, 2002
292
0
Virginia
Originally posted by rbx
as for the effiency issue thats open for debate..
I guess. But in order for a belt drive to be as efficient as a chain, it can't stretch more than a chain, which is one problem with belt drives under load, so the belt has to be the reinforced variety. Then it's heavy and stiff, and still inefficient because it's now harder to bend around the cog, which is the second place where belt drives are inefficient. They lose more energy bending around the cog than a chain does rotating on its pins. So they aren't as efficient as chains for bicycle usage. Maybe that will change one day.

This topic is addressed in the book, Bicycle Design.

Bike chains are very efficient. The larger the cog, the greater the efficiency according to Johns Hopkins.

Even though they have a bike with a belt drive, Jericho themselves have said that it sucks in muddy conditions.
 

gus

Chimp
Mar 17, 2002
20
0
did this back in 92 for some world champ tandem roadies .
Light saved about 2lbs.
no slip Gates ( Kevlar cords)
Tooth profile fritionless(pat.by Gates) develped by Schiele (a tactrix mathematical function) as an evolute form of catenary.
To make a long story short slick as sh8t..(gus/Arrow)
 

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