# Gates belt drive article in today's Denver Post



## moonmoth (Nov 8, 2008)

An article today about Gates' belt drive system.

"I don't see why any commuter bikes should have chains," Greg Vigil from Gates says.


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## MB1 (Jan 27, 2004)

moonmoth said:


> ..."I don't see why any commuter bikes should have chains," Greg Vigil from Gates says.


Could it be because they are cheap, reliable, readily available and proven?


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## CleavesF (Dec 31, 2007)

^^^ remember, you can't make money if you don't convince people there's a problem. 

This is as good as that weight lost drug I was taking yesterday with my antidepressant and my dry eyes medicine.


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## Mr. Versatile (Nov 24, 2005)

I like the idea of belt drive. I can see how it would be lighter. It would also take much less maintenance, be cleaner, quieter, not require cleaning or lubing, and last much, much longer than a chain. It would also me much less prone to breaking. Harley Davidsons have been using belt drives for many years without problems. If they can design a belt that can withstand that kind of torque they can certainly design one for bicycles.


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## Kerry Irons (Feb 25, 2002)

*Efficiency*



Mr. Versatile said:


> I like the idea of belt drive. I can see how it would be lighter. It would also take much less maintenance, be cleaner, quieter, not require cleaning or lubing, and last much, much longer than a chain. It would also me much less prone to breaking. Harley Davidsons have been using belt drives for many years without problems. If they can design a belt that can withstand that kind of torque they can certainly design one for bicycles.


IIRC, belts are significantly less efficient than chain drive. For a city bike, maybe that's not a big issue. With positive experience a belt drive with an internally geared hub might make a good choice for a commuter over shorter distances. The thing that gives one pause is that we've been hearing about this breakthrough for 15 years. When is it going to actually happen?


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## Pablo (Jul 7, 2004)

MB1 said:


> Could it be because they are cheap, reliable, readily available and proven?


... and repairable.


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## Pablo (Jul 7, 2004)

moonmoth said:


> An article today about Gates' belt drive system.
> 
> "I don't see why any commuter bikes should have chains," Greg Vigil from Gates says.


... says the guy who doesn't sell chains.


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## Mr. Versatile (Nov 24, 2005)

Kerry Irons said:


> IIRC, belts are significantly less efficient than chain drive. For a city bike, maybe that's not a big issue. With positive experience a belt drive with an internally geared hub might make a good choice for a commuter over shorter distances. The thing that gives one pause is that we've been hearing about this breakthrough for 15 years. When is it going to actually happen?


How much less efficient & why would that be?


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## MikeBiker (Mar 9, 2003)

> The system requires a frame that separates to install the one-piece belt, meaning bike manufacturers must engineer a bike specifically for a Gates belt. Assembly factories have to be retooled and workers retrained. Then comes convincing dealers and buyers that the added cost of the system — about $200 to $300 over a chain drive — is worth it.


The belt isn't a replacement for a chain, it requires a special bike that is specifically designed for the belt. $200 to $300 can buy a lot of chains and lube.


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## weltyed (Feb 6, 2004)

i see the biggest obstacle for belt-drive bike as commuters/urban rides is the problem with changing a flat. to me that is the biggest issue.
next is avalability of internally geared hubs.
third is belt replacement.

but i honestly dont know much about the subject.


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## Pablo (Jul 7, 2004)

MikeBiker said:


> $200 to $300 can buy a lot of chains and lube.


C()de? :blush2:


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## Kerry Irons (Feb 25, 2002)

*Numbers*



Mr. Versatile said:


> How much less efficient & why would that be?


I have no idea about the difference in efficiency. I think I've read numbers someplace but cannot remember what or how much, just mechanical engineers commenting. The reason is essentially the same reason that rubber tires have more friction than steel wheels on rails (trains). There is hysterisis flex in the rubber belt and friction from the side of the belt and the side of the pulleys.


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## Harley-Dale (Sep 2, 2011)

Mr. Versatile said:


> I like the idea of belt drive. I can see how it would be lighter. It would also take much less maintenance, be cleaner, quieter, not require cleaning or lubing, and last much, much longer than a chain. It would also me much less prone to breaking. Harley Davidsons have been using belt drives for many years without problems. If they can design a belt that can withstand that kind of torque they can certainly design one for bicycles.


And yet, I know of many who have converted their belt drive to chain. I dont see the need on a street bike, but a bike at the strip it makes sense. Since I dont race my Harley, the belt is good enough for my riding.

I would "guess" that there is more friction with a belt, over a properly lubed and manufactured chain. The rubber/fiber going from a straight orientation to a curved shape around the pulley or gear will have a fair amount of tension to it. Not noticeable on our Harleys, but on a human powered bicycle, I can see a drawback.

Also, as the radius of the pulleys decrease, there is a propensity for more tension and friction. We have seen this on the final drive pulleys on Harleys--going to a smaller tooth front pulley, decreasing the diameter, we see more belt fatigue and belt failures at lower mileage. There is a point where too much of a bend is a bad thing for a belt.

Anyway, not trying to argue either way. I can only think that a belt would be difficult to engineer well to work on a small diameter gear on a bicycle--or at least better than high end chains work on bicycles today.


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## Fixed (May 12, 2005)

weltyed said:


> i see the biggest obstacle for belt-drive bike as commuters/urban rides is the problem with changing a flat. to me that is the biggest issue.
> next is avalability of internally geared hubs.
> third is belt replacement.
> 
> but i honestly dont know much about the subject.


The internally gear hub itself is also less efficient. 

Maybe the smarter way to go is to invent an "oil-less" chain.


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## MikeBiker (Mar 9, 2003)

Fixed said:


> The internally gear hub itself is also less efficient.
> 
> Maybe the smarter way to go is to invent an "oil-less" chain.


I've almost got one invented using magnets and superconductors. The flux capacitor has temporarily stymied.


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## Kerry Irons (Feb 25, 2002)

*From physics*



Fixed said:


> The internally gear hub itself is also less efficient. Maybe the smarter way to go is to invent an "oil-less" chain.


Personally, I would prefer those old standbys from physics: the frictionless pulley and the weightless rope


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## thumper8888 (Apr 7, 2009)

MikeBiker said:


> I've almost got one invented using magnets and superconductors. The flux capacitor has temporarily stymied.



See, that's where guys always take a wrong turn.... If you just epoxy a static relief valve into the socket for the flux capacitor the power will flow like honey onto a biscuit.


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## thumper8888 (Apr 7, 2009)

Kerry Irons said:


> Personally, I would prefer those old standbys from physics: the frictionless pulley and the weightless rope


But those things are only made possible by the static relief valve and the perpetual zizz-wheel. Folks are always trying to get something for nothing out of physics, forgetting it's kind of a balance sheet.


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## 55x11 (Apr 24, 2006)

Harley-Dale said:


> And yet, I know of many who have converted their belt drive to chain. I dont see the need on a street bike, but a bike at the strip it makes sense. Since I dont race my Harley, the belt is good enough for my riding.
> 
> I would "guess" that there is more friction with a belt, over a properly lubed and manufactured chain. The rubber/fiber going from a straight orientation to a curved shape around the pulley or gear will have a fair amount of tension to it. Not noticeable on our Harleys, but on a human powered bicycle, I can see a drawback.
> 
> ...


Misalignment problems with belts is another thing to consider - read BikesnobNYC:
Bike Snob NYC: The Indignity of Commuting by Bicycle: Playing With Your Test-Cycle

I think belt drives are a bit of a fad and there is a reason why chains have been used for over 100 years.


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## Guest (Nov 13, 2011)

If the concern is avoiding "chainring tatoos" and greasy slacks for people commuting in street clothes, I can understand using an internally geared hub and putting a chainguard/barrier over the chain. I don't see how the belt really provides a significant advantage compared to a chain. 

Now, something that i do think would be an interesting novelty to have on a bike would be a belt based CVT, though I'd expect even if it could be done, it would be a nightmare to maintain:










In the end it would still probably be easier to make an internal hub CVT with regular chain drive...


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## Kerry Irons (Feb 25, 2002)

PhotonFreak said:


> If the concern is avoiding "chainring tatoos" and greasy slacks for people commuting in street clothes, I can understand using an internally geared hub and putting a chainguard/barrier over the chain.


In fact, a fully enclosed chainguard with an oil bath will be extremely low friction, essentially maintenance free, and the chain will last a VERY long time. This is standard practice on some of those "Dutch commuter bikes."


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## 55x11 (Apr 24, 2006)

Kerry Irons said:


> In fact, a fully enclosed chainguard with an oil bath will be extremely low friction, essentially maintenance free, and the chain will last a VERY long time. This is standard practice on some of those "Dutch commuter bikes."


but fully enclosed chainguard make such a pain to repair a flat tire!


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## honkinunit (Feb 13, 2005)

The solution is neither belt nor chain. The solution is this:

1900 Pope / Columbia Model 65 Chainless Antique Mens Bicycle


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## Harley-Dale (Sep 2, 2011)

Honk, what a post! I went to the link and stepped into the 60's, man. A friend in southern Oregon had one of those and we teased him all the time because it didnt have a sprocket and chain. It was an "old timers" bike (hey, we were 6 yerars old, WTF did we know, right).

Anyway, it was a beat up old red thing (it actually had been repainted multiple times) and I remember helping him get the oil plug out with my dads tools and putting a bunch of 30 weight oil in there.

Wow, I had forgotten all about those days. Cool reminder. Wish I had that kids old Pope, would be quite a bike to restore.

Dennis


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## Kerry Irons (Feb 25, 2002)

*Shafted*



honkinunit said:


> The solution is neither belt nor chain. The solution is this:
> 
> 1900 Pope / Columbia Model 65 Chainless Antique Mens Bicycle


Actually, when it comes to weight and drivetrain losses, shaft drive is probably even worse than belt drive. It's been tried on bicycles many times over the years (100 years!) without any staying power in the marketplace. It's a cool novelty item, but not practical.


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## honkinunit (Feb 13, 2005)

Kerry Irons said:


> Actually, when it comes to weight and drivetrain losses, shaft drive is probably even worse than belt drive. It's been tried on bicycles many times over the years (100 years!) without any staying power in the marketplace. It's a cool novelty item, but not practical.


Actually, a shaft is massively practical if you want to look cool. Just get Gary Fisher to make one and they'll take off. 

Schwinn sells a modern shaft drive bike, or at least they had one in their catalog a few years ago. I have to believe that a little modern engineering applied to a shaft would make them very practical. Internally geared hubs have relatively high drivetrain losses, too, but they are staging a comeback. 

One fact to remember in the chain vs. whatever debate is that the measurements are always taken with a perfectly clean and lubed chain in perfect alignment. Take a look at the average bike and this is a pretty rare situation. 

There is a team sponsored by Gates that is competing in national level cyclocross events with single speed belt drive cyclocross bikes.


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## BryanSayer (Sep 22, 2009)

PhotonFreak said:


> I
> Now, something that i do think would be an interesting novelty to have on a bike would be a belt based CVT, though I'd expect even if it could be done, it would be a nightmare to maintain:
> 
> 
> ...


nuvinci makes a belt drive version of the N360. I'm going to put either a belt drive or a chain drive on my next commuter bike.


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## AndreyT (Dec 1, 2011)

weltyed said:


> i see the biggest obstacle for belt-drive bike as commuters/urban rides is the problem with changing a flat.


Can you elaborate on that? I don't see how a belt-drive would make any difference with regard to changing a flat. 

It is obvious that no-seam belts require an "openable" frame for belt installation and replacement. For some reason people often translate this into some perceived difficulties with rear wheel removal, while in reality belts are no different from chains in that context.


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