Bicycle Mechanics - has there ever been a belt drive?

this occured to me the other night for some reason. has anyone ever used a belt drive on a bicycle? it might be difficult with gears, but would work for single speed bikes.
harley davidson uses a belt drive on there bikes, they claim the belts have a longer life then chains and don't stretch.
maybe there would be some slippage even on a belt with teeth that would make the system less efficient?
anyone ever seen or thought about doing this? it would probably wiegh less than a chain and avoid sprocket wear. i bet if people put some thought into it they could probably even make it work with gears.

Yes.

One of the Moultons featured a belt drive and I think a few folders flirted with it from time to time to address the cleanliness issue. David Gordon Wilson of Bicycling Science has experimented with them but they simply are not as efficient as chain drive. Plus, I think he had problems with slippage with smaller rear drive pulleys.

Dave

Unfortunately there has been. The Strida plastic bike used one. The bike is a total monstrosity in every way.

Maybe there are some composite materials which would be adaquate for a belt, used together with a hub gear system.
Motorbikes have power to waste on transmission losses, and the gearing is used to lower the revs from the engine, the complete opposite of bicycles.

ahh well i figured efficiency might be the issue, neat idea if they could work that out.

Originally posted by shaharidan
ahh well i figured efficiency might be the issue, neat idea if they could work that out.



OK.


Now what about SHAFT DRIVE? :)

definite efficiency loss in shaft drive, atleast if its set up like it is on cars and motorcycles. since its not direct drive from the pedal to the rear well you lose efficiency. with a belt it atleast be direct drive, the efficiency loss would occur with belt slippage.
i suppose a shaft drive that was set up similar to old steam locomotives would be direct drive, but im not sure how it could be done, i also imagine peddling might feel very strange also. and no idea if its effecient or not, be a neat experiment though.
wish i had a full service machine shop in my basement to try this stuff out :)

o a full service machine shop, and a ton more time and ability :)

Shaft drive was introduced in the late 1890s:
http://www.jimlangley.net/brake/columbia02.html
http://ah.bfn.org/h/pierce/pierce/

A few companies continue to pursue the design:
http://www.sussex.com.tw/se2.htm

Two brands being marketed with it:
http://www.amis-intl.com/bikeindex.html
http://www.chainlessbikecompany.co.uk/mainframe.htm

I have a shaft drive bike from the late1890's hanging in my shop. Belongs to the store owner.
By the way a toothed belt on a toothed pulley does not slip. They are also efficent and quiet. That is why just about any car built in the last 15 years uses one for a timing belt rather than chain or gear drive.

Jericho bicycles produces a frame that is compatible with both a chain drive and a belt drive. The rear triangle of the frame has a place at the dropout where the frame comes apart to slip the belt onto the system. It is only offered in their single speed setup but I have heard that it is pretty cool. Check it out here. http://www.jerichobicycles.com/html/frames_leadfoot.html

Do you think it would be possible to create a metal free bike? I always thought the drive train would be the limiting factor. This belt drive seems to solve that.

Originally posted by livngood
Shaft drive was introduced in the late 1890s:
http://www.jimlangley.net/brake/columbia02.html
http://ah.bfn.org/h/pierce/pierce/

A few companies continue to pursue the design:
http://www.sussex.com.tw/se2.htm

Two brands being marketed with it:
http://www.amis-intl.com/bikeindex.html
http://www.chainlessbikecompany.co.uk/mainframe.htm



Wow....funky. I was joking too! :)


Be worth buying one, just to confuse folk...

Ive thought about that for a beach and surf bike. You can get good teflon plastic bearings, but may have problems figuring out how to attatch things without metal threads.
You would also have to discard any metal-based sizing standards for components.
You could probably make a good low-performance fun bike, but nothing that would compete in a race.

You can still find belt drive bicycles in Japan. For commuters, they have another advantage of being clean. Tokyo commuters who bicycle to the train station and then to work, don't mess around with changing clothes after the commute. The wear their office clothes from home to work and back.

The belt drive doesn't use oil, thus reducing the risk of having clothing getting soiled from a greasy chain AND clothing does not get ruined in the chain/chainring if a belt drive is used.

Belt drives are used on single, three, five, and seven speed internal hubs.

Saw one once in a Mercedes dealers when I took my car in for a service. I was looking at it, and the salesman said take it for a ride around the lot. I did. Impressions? Total, utter sh1t. Mercedes should stick to what they do best, make cars. Maybe they had this bike made for them but wherever it came from, crap it was and crap it still is.

I enquired about the life of the belt. Reply? Not too long but we carry spares in stock.

Great sales pitch.:rolleyes:

I saw someone riding a shaft-drive bike at the Liverpool Cycle Show a couple of years ago. EERILY quiet!!

Actually, the first recorded pedal bike was a shaft drive, if it can be called that, (It was propelled by either treadles or a hand crank) and was mentioned in the press in 1842. A man (believed to possibly be Kirkpatrick MacMillan) was arrested in Glasgow for driving on the sidewalk and knocking over a child, and he claimed to have come 40 miles.

Many old tricycles, bicycles and quadricycles attempted shaft drive with treadles.

check the american bicycle museum [run a search]you'll easily find there web site
I believe there was a belt drive in the late 1800's?even a shaft drive bicycle late 1800's

Originally posted by captsven
Do you think it would be possible to create a metal free bike? I always thought the drive train would be the limiting factor. This belt drive seems to solve that.

Because of its metal (I assume) axles, the Strida (www.strida.com) falls just a few percentage points short of your stated goal. Michael W has already commented on it in this thread. It's a great bike if you don't do hills, don't cover more than a mile or two at a time, are not in a hurry, and don't weigh more than 165lbs/75kg. Alot of boat owners like them for cruising around the docks or for quick errands, and they probably make sense for some train or bus commuters, as well. It might be tough to trigger a traffic signal loop detector with one. At 10kg, I think I'll keep my Bianchi, instead.

In "The Bicycle" by Pryor Dodge there are some wooden and bamboo framed bikes. Still lugged with steel and there are other metal parts as well.

A BBC programme called the Antiques Roadshow interviewed the owner of one of the last remaining wooden frame bikes in the UK. The valuation given on the bike was a whopping £7000 or about $10000. It is still rideable.

As a work of art - it was incredible.

There has been a belt drive that works just as well as a chain - check out the new Space Savin iXi bike - www.ixibike.com

Do you think it would be possible to create a metal free bike?

Did y'all hear about how Audi was working on a way to make belt-drive more efficient. Belt-drives are what allow continuously-variable transmissions (CVTs) to work. (it's the only kind of transmission available on the toyota prius and is available on some other recent cars.) Audi apparently put a metal chain of some sort inside the belt used in their CVT. CVTs and belt drives in general are better suited to cars, though, because cars have more power and more loss of power in the transmission than bikes. Bicycle chains are quite efficient power-transfer devices and I don't think it's worthwhile in most bicycling situations to replace chains with something else. If you don't want a chain, you could always buy a highwheeler though.

A belt or shaft drive would work perfectly fine with an internally geared hub. Remember in a Harley the belt is not part of the transmission system. The belt only transfers power from the transmission to the rear wheel and does not change gears itself. On a bike, the chain is actually part of the transmission - it moves from one chainring to another or from cog-to-cog in the back. A chain is efficient because it does not stretch along it's long axis in normal use, but the joints between the links let it angle a little bit between rings and cogs (look at your chain when it's on the big ring in front and the biggest cassette in the back, for example). This would not work as well with a belt drive. Belts can be designed to not stretch - such as in a Harley motorcycle - but they would not allow much angle when changing gears. Also, there is no removable link in a belt - they are continuous. To get a new belt on a motorcycle you have to remove the pulleys on which the belt rests - a huge job. Cetainly one could design a belt to meet all the needs of a bicycle but it would probably be very chain-like! Why not use the real thing which is light, efficient, and can be removed without taking off your crank and rear cassette?

I wonder if an all-plastic bike would float...? :D

I wonder if an all-plastic bike would float...?

Probably. But the real question is, would it float well enough to keep the rider's head above water?

Personally, I want a bike that has those big swimming-pool-doughnut floats for tires, so I can ride on water. ;)

Boy!! I'm surpirzed that no one mentioned the Schwinn belt
drive bike of the recent past.

Two things to add to this...

First...Don't I remember a two wheel drive mountain bike from about ten years ago? I think it was a military experiment. As I recall it had some sort of flexible shaft going to the front wheel.

Second...speaking of wooden bikes...does anyone remember in a late 80's Bicycling Magazine there was a picture of an ALL wooden bike a guy hand carved. He had carved every bearing, chain link, etc... It was a working model but of course unridable. I saved the issue for a long time because of the picture, but have since lost it.

There is at least one 2 wheeled drive mountain bike available today. It has a long chain going from the back wheel to the front, and the main drive system is similar to conventional bikes. I forget what it is called though.
How about a belt drive bike, with some type of tensioner, and a 'soft' rear 'cog'? So you pedel harder, and the cog compresses giving you a lower gear ratio. I guess that would be impossible to get up hills though. What about the same idea but for the front cog? Im just thinking...

I recall in the 80's my LBS in South Carolina had a constantly variable crankset. I can't recall exactly how it worked, but it seems it would expand or contract with pressure as Matheprat is suggesting, though it was for a conventional chain.

There is at least one 2 wheeled drive mountain bike available today. It has a long chain going from the back wheel to the front, and the main drive system is similar to conventional bikes.

This seems to me to be the most bass-ackwards way to do 2-wheel-drive, but I've never tried the bike, so what do i know?

There are quite a few front-wheel-drive, low-riding recumbent bikes. Their system just routes the chain up to where frame and fork meet,* and then allows it to twist when the front wheel is turned (which the chain does quite easily) as it goes down from the head tube to the wheel. The same thing could be done with a mountain bike if anybody wanted to, running one chain off the right side of the bottom bracket for a conventional drive system and another chain off the left for a front wheel drive. You'd probably set up the front-wheel drive-system to work only at your lowest gear (and just freewheel at higher speeds) to avoid having 4 derailleurs. But all-wheel-drive wouldn't be for going fast/straight-ahead anyway.

*using little cogs like the ones in a rear derailleur

Link to a 2wd mountain bike:
http://www.christini.com/tech-about.php

It uses a normal drive train for the back wheel, then transfers power to the front with an internal shaft drive.

there have been a couple of wood framed bikes on ebay within the last couple years, all I saw were in rough shape but not very expensive.
there were also some kids bikes with belt drives

and shaft drive, and another modern beltdrive

Contrary to what some posters indicated, belt drive is less efficient than chain, not because of slippage (toothed belts solve that), but because of friction in engaging/releasing the belt teeth, and friction on the lateral support. Chains provide metal-to-metal (with some lubricant of you think about maintaining your bike once in a while) in the engagement/release of each cog/link pair. So yes, cars have gone from chain to belts for cam drive, and (some) motorcycles as well for the drive; but the reasons for these changes are noise (belts are quiet), and cost (a timing belt is cheaper than a timing chain, but does not last as long).

As for shaft drive, you are combining two 90 deg andlge gears (one each end of the shaft), and at least 2 bearings for the shaft; in addition, the angle gears tend to be small, to avoid a huge box in the front. That combo (small angle gears) is a perfect combo for high friction, and the shaft bearings don't help any.

For curiosity's sake, my design project in university involved a... hydraulic drive, where the pedals actuated a variable-displacement pump, and a pair of hoses then drove the rear wheel via a constant-volume hydraulic motor. Not sure the contraption would have been manufacturable, not to mention the kind of friction and losses associated with the pump and motor. The good news was, it gave continuously-variable ratio between the pedals and rear hub. Don't look for it in your local shop...

Though I have not had University experience with it, I too have been sketching and theorizing on a fluid drive bike. It would seem you could have valves that open/close with variable pressure and therefore have constantly variable gearing. Is this similar to what you were working on Zouf?

Though I have not had University experience with it, I too have been sketching and theorizing on a fluid drive bike. It would seem you could have valves that open/close with variable pressure and therefore have constantly variable gearing. Is this similar to what you were working on Zouf?
Not quite; our "thing" had a gear lever of some sort, that changed the flow vs RPM of the pump; so you could get more/less flow for a given rpm, rather than more/less chain speed as you get from a front deraileur. So it was a "manual shift, infinitely variable" type of drive. You would have to add some kind of servo-valve to modulate the pump based on rpm to get an "automatic, infinitely variable" drive.

Or you could always drop the hydraulics, and go the snowmobile way, with v-belt and variable diameter pulleys: this concept has been used in very small, very cheap, very foreign cars for a long time, but is now mainstream thanks to Audi's CVT - albeit with a chain rather than a belt. And here, you are talking about major, major friction losses. The days of the TdF peloton going up Alpe d'Huez with the smooth whining of v-belts is still far away from us, methinks. And the days where the follower cars will carry a few gallons of hydraulic fluid as well.

I have a shaft drive bike from the late1890's hanging in my shop. Belongs to the store owner.
By the way a toothed belt on a toothed pulley does not slip. They are also efficent and quiet. That is why just about any car built in the last 15 years uses one for a timing belt rather than chain or gear drive.

except, like, all nissans...

i think that cool shaft drive bicycles are the bee's knees, fwiw.

-rob

except, like, all nissans...



-rob

my wife's Nissan Micra tossed its timing belt and cost extreme bucks to repair at the dealer, so some of them have timing belts. (might be corrected here as micra would be 20 yrs old if we still had it)

For curiosity's sake, my design project in university involved a... hydraulic drive, where the pedals actuated a variable-displacement pump, and a pair of hoses then drove the rear wheel via a constant-volume hydraulic motor. Not sure the contraption would have been manufacturable, not to mention the kind of friction and losses associated with the pump and motor. The good news was, it gave continuously-variable ratio between the pedals and rear hub. Don't look for it in your local shop...

Hello Zouf,

Is there a way I could peruse your research into the hydralic drive? Or perhaps you have a bibliography of work done in this arena. I am seriously considering making such a drive, but not before I completely model it and predict the losses and overall weight it would likely have. At first blush I am considering a simple but very high precision (low leakage) reciprocating piston pump on the cranks--designed for the "one optimum cadence", and a similarly low leakage, variable swash plate motor where the cluster resides on the freewheel. Perhaps naively, I would think that paying close attention to very high precision in the various pistons and keeping the hydraulic lines relatively large to minimize any flow shear losses should make it compete with a multi-sprocket chain system in efficiency.

Regards,

Bill.

Larger diameter pipes means you need a large volume of fluid in the system...
What would that add in terms of weight, do you think...
Not to mention the pipes themselves...

My guess is the entire gearing system would weigh 5-6 lbs or more...

Hello Zouf,

Is there a way I could peruse your research into the hydralic drive? .
He hasn't been back in a year. http://www.bikeforums.net/member.php?u=15385
Next time you have a question relating to an old dead thread try PMing the person rather than digging up old dead threads

Welp, this was the first time I read it, and it was very interesting. For what that's worth.

Me too. Half the time I don't even realize they're old. Good reading.

I was going to post some interesting info and pics of a new belt drive bike that I saw this week but after Raiyns post I didn´t bother- catch 22- if I post on the old thread I will be flamed for reviving old threads and if I start a new one I will get flamed for not doing a search and posting on the old thread :p

royalflash, please post the belt drive info, it's an interesting topic for me at least. As far as your other issue the ignore list is a useful tool - big time saver.

I'd like to know more about the efficiencies of belt drives. Manufacturers information suggests efficiencies near that of a well lubricated chain and better than a poorly lubricated chain. The no mess-no maintenance aspect of a belt drive is compelling too. With the way a toothed belt distributes load on a pulley and the greater toothed area it also opens the possibility of plastic or at least cast drive cogs.

From my perusal of sources it looks like a belt appropriate for a bicycle would cost two or three times what a chain does. Maybe this is the big problem?

As far as a hydraulic drive the losses will certainly be excessive. A chain drive on a bicycle is probably 98% efficient and I'd guess by the time all is said and done the hydraulic would be 80% at best. The hydraulic efficiency would also fall off as speed is increased.

There was a shaft drive bike being promoted somewhere recently. Seemed like an inappropriate and complicated solution to a simple problem.

Performance Bike sells a belt driven bike. (http://www.performancebike.com/shop/profile.cfm?SKU=19721&subcategory_ID=3060)

Thanks Dan, I never would have thought a 10mm belt would be strong enough. That's one ugly frame on that thing!

I have a shaft drive bike from the late1890's hanging in my shop. Belongs to the store owner.
By the way a toothed belt on a toothed pulley does not slip. They are also efficent and quiet. That is why just about any car built in the last 15 years uses one for a timing belt rather than chain or gear drive.
Sorry, but timing belts should be outlawed- they become an expensive scheduled replacement- rather than a chain that will last the lifetime of the vehicle (theoretically). My 2000 Toyota has a chain.

On a bike, the chain is actually part of the transmission - it moves from one chainring to another or from cog-to-cog in the back.

Not always the case... Ever heard of a SS or fixed gear?

http://www.bscycle.co.jp/catalog/albelt/2005/05products-ADSTP.html

This bike has a belt, and also has built in tire pressure gauges.

This page has a diagram of the belt drive system, which is not as straightforward as it looks. It uses a floating gear, though the translation of the page is too confusing to understand much more than that. Maybe a Japanese speaking member may be able to explain it.

http://www.bscycle.co.jp/catalog/albelt/2005/05albelt-point.html