Belt drive

[Rockinthecasbah]

those cut outs are no match for a good piece of gravel or an odd shaped stick I think it would be cool for a roadie but things in the dirt need chains

[Rob]

http://www.carbondrivesystems.com/

You can use it with a Rohloff Speedhub to get a good range of gears.

[HUGH]

So these are pictures of my rear drop out on the drive side. If you remove the two allen bolts you can spread apart the seat stay from the dropout/chain stay just enough to slip a belt in there. The belt drive thing has been around for a while. I just don't think it took off. This frame is 5 years old.





Hope this helps..

HUGH

[Ladd Jasper]

Originally Posted by HUGH

Hope this helps..

Totally helps--very clear in your pics. Looking back at the Spot site, the break where the dropout splits is quite obvious now.

Thanks, Hugh.

[Pho'dUp]

Hmmm... interesting. Still waiting for a real world end user to give a review. I applaus Spot for being a pioneer here. They seemed to be really on top of the game in the SSpeed world 5 years ago... But seemed they missed the early boat on the 29'ers.

Comes down to cost to benefit ratio for me. One manufacturer means one expensive price for chain rings, cogs, and belts right? Besides, with a laterally stiff frame, I haven't broken a chain in a long time. (hope I didn't just jinx myself). Chain SSpeeds are pretty maintenance free as it is. So can't see a reason to go to the belt system unless the performance jump is tremendous.

[CalEpic]

Carbon belts are extremely strong. Cogged designs such as this are not really affected by sand and small debris but water can be a problem (causes the belt to slip even with cogs) I'd like to see a real world test in water and mud.

The advantages are that they are clean, quiet and virtually maintenance free. They would most likely outlast a chain by a longshot. In an ATV application they are comparably priced to a non-o ring 520 chain. They are also sealed to prevent water and debris from causing problems. Maybe with the lower torque output of a bicycle it wouldn't be a problem?

C

[Dino Brown]

Originally Posted by CalEpic

Carbon belts are extremely strong. Cogged designs such as this are not really affected by sand and small debris but water can be a problem (causes the belt to slip even with cogs) I'd like to see a REAL WORLD TEST in water and mud. The advantages are that they are clean, quiet and virtually maintenance free. They would most likely outlast a chain by a longshot.

All in favor of H*U*G*H being our "real world tester" say (I). ......

Make it happen Hugh!

[northshore]

Pretty interesting but I wonder about the reliability of a belt versus chain. IE: Nissan cars all use timing chains versus belts. The first thing that comes to mind that could easily effect this belt is dirt/mud/water/heat. Any kind of exposure to weather changes can harden the rubber on a belt making it prone to cracks, etc.... Anyone want to do a long term test?

[doulos]

I'd test it... if somebody gives me the bike for free

[granny ring]

Another drawback is gearing changes. The belt is a fixed length. New gear ratio new length belt.

[BrewMaster]

Originally Posted by northshore

Pretty interesting but I wonder about the reliability of a belt versus chain. IE: Nissan cars all use timing chains versus belts. The first thing that comes to mind that could easily effect this belt is dirt/mud/water/heat. Any kind of exposure to weather changes can harden the rubber on a belt making it prone to cracks, etc.... Anyone want to do a long term test?

Rubber compounds are resistant to water at ambient temperatures. Some rubber compounds degrade in UV light or ozone if they don't contain antioxidants or antiozonants. I would suspect that these belts account for their intended use and use stabilized rubber compounds that can withstand normal outdoor conditions.

The Rohloff idea brings the belt driven bike idea to life. Me likey.

[Chewyeti]

ooh... and no one has ever considered a belt tensioner?

look under the hood of your car for an idler pulley or a tensioner.

[Rockinthecasbah]

youd have to run an internally geared hub for any gears , for ss a belt tensoner but after ss ing my vertical droput jump bike I learned that even if you do drop 1 or 2 teeth you might not be able to properly tension it unless you ran it through something like a normal rear derailer

[Chewyeti]

Originally Posted by Rockinthecasbah

youd have to run an internally geared hub for any gears , for ss a belt tensoner but after ss ing my vertical droput jump bike I learned that even if you do drop 1 or 2 teeth you might not be able to properly tension it unless you ran it through something like a normal rear derailer

also known as a tensioner. That little wheel that puts some force on the chain, to take up the slack

[uzziboy]

Originally Posted by mechmann

there was lots of buzz about this system at Ibike. lots of people rode it and only one commented (that i know of) negatively.

would be interesting to try with a Rohloff!!

I run a rohloff with an uzzi slx i would love to try a belt just for arguments sake. If anyone has the companys info for the belt drive please send it to me thanks

[Rockinthecasbah]

i was saying like a normal derailer size wise you would have to have a large belt and run it way low like a medium or long cage , that would equal out to more weight then a chain with the extra metal in the pulleys for the belt, plus the drawbacks of using a belt in a dirty enviorment = benifits of 1 percent efficiency dont beat the drawbacks of increased weight, susceptibility to dirt and rocks plus a bolt together part of the chainstay to creak.

Originally Posted by Chewyeti

also known as a tensioner. That little wheel that puts some force on the chain, to take up the slack

[Chewyeti]

chains weigh more than belts

do you drive your truck through water? mud? dust? dirt? your serpentine belt in your truck survives.....

it wont have any issues on a bike setup. and the toothed pulley it rides on has 'drains' to let particulate and debris escape.

touche!

the only drawback is not being able to run a geared setup without a planetary hub.

[Rob]

www.carbondrivesystems.com

I asked the guy about water and he said it actually makes the system run smoother/quieter when it's wet...

Carbon Drive Systems: the next big thing?

Aggressive ports allow for mud evacuation.
Photo ©: James Huang If you could have a drivetrain that was lighter, smoother, longer lasting, totally silent, more responsive, and required no lubrication, would you buy it? The folks at start-up company Carbon Drive Systems certainly hope so, and they claim its new system not only offers all of the above but a free cup of frozen custard, too (okay, we're lying about the last part, but that does sound good right now. Mmm... custard).
The system is built around a 52g toothed 'polychain' comprised of multiple strands of stretch-resistant carbon fiber embedded in flexible polyurethane. The matching proprietary chain ring and cog are made from CNC-machined aluminum, and the whole shebang weighs just 180g (yes, we said "180g," and no, it's not a typo. Read it again if you must).
The embedded carbon fibers are also said to transfer tension faster than conventional roller pin chains for more immediate response to pedal inputs, and CDS even claims belt lives up to 10,000 miles for its 'endurance' model (a smoother running 'performance' system supposedly offers only marginally shorter lifespans). Gaping ports in the troughs of the cog and chain ring teeth also appear rather capable of evacuating even the nastiest goop, and after eight iterations of design refinement, CDS is confident in the final product.
So what's the catch, you ask? The system will almost certainly be forever limited to fixed-gear or singlespeed applications, and the belt currently cannot be separated and respliced so you probably won't be able to use it on your current rig very easily. However, CDS is working with singlespeed maverick Spot Brand to bring the system to market on a wide range of bikes thanks to a clever 'keystone' dropout that allows users to easily split the drive side chain stay and seat stay with virtually zero visual indication that it's anything out of the ordinary. The dropout is only made in steel for now but CDS says titanium and aluminium ones are imminent.
The non-separating belt
Photo ©: James Huang Spot will offer five CDS-equipped bikes next year, including the Longboard singlespeed 29er, a singlespeed cyclo-cross bike, the Sprawl urban fixie, the internal hub- and fender-equipped Highline commuter, and Spot's standard 26" singlespeed MTB model. Keystone dropouts will be standard equipment across the board, although conventional one-piece dropouts will still be available by special request. CDS also reports that two other companies have signed on for 2009.
Notably absent from the lineup, however, is a full-suspension model. As with any singlespeed drivetrain that doesn't rely on a tensioner, the CDS design is rather intolerant of changes in effective chain stay length as the rear end moves through its travel. While this doesn't necessarily completely eliminate the possibility of a full-suspension rig altogether, it does severely limit the types of systems on which it will work in its current form (dropout issues notwithstanding). Nevertheless, CDS says it has already begun a collaborative project with another well-known builder for a full-suspension model so we'll see where that leads soon enough.
One question left currently unanswered, though, is that of drivetrain efficiency. Conventional roller pin chains are also among the most efficient drive systems on earth, and it's difficult to imagine that a polyurethane belt and its seemingly obvious hysteresis effects can improve on that. CDS is optimistic nonetheless, however, and is currently undergoing third party tests to confirm (or refute) its claims.
Regardless of those findings, CDS reports that Quality Bicycle Products has already signed on to distribute the system and its individual components. A 'framebuilder kit' will also be available that will include a belt, chain ring, rear cog, and dropouts, and CDS is also open to enquiries from other OEM manufacturers who wish to use the drivetrain.
Currently, chainrings are only available in 32/34/42/44T (effective) sizes and Shimano spline-compatible cogs in 16/18/20/22T sizes. Chainrings are only offered in four-bolt 104mm BCD patterns for now but CDS says more chain ring and cog sizes and patterns are on their way. Retail prices for the chainrings and cogs range from US$38-45, and belts will cost approximately US$60. Further information is available on the Carbon Drive Systems web site.

source- http://www.cyclingnews.com/tech.php?...007/news/08-28

[Rockinthecasbah]

the serpentine belt on the truck isnt sitting exposed right behind the front wheel it can only drain small things odd shaped rocks and twigs will get thrown form th front wheel into the front pulley and cause a rough ride or belt failure, you could rin the system enclosed, but then agian why, O and the chain neing heavier comment a hollow pin chain with a small tensoner like my dmr is not heavier then a belt and large pully tensoner system, with the added metal of the pulleys

Originally Posted by Chewyeti

chains weigh more than belts

do you drive your truck through water? mud? dust? dirt? your serpentine belt in your truck survives.....

it wont have any issues on a bike setup. and the toothed pulley it rides on has 'drains' to let particulate and debris escape.

touche!

the only drawback is not being able to run a geared setup without a planetary hub.

[ka0t1c07]

if the belt is tension right, water will not make it slip. I seen cars with wet timming belts and they dont slip, even at 7000 rpm.