Belt driven drivetrain
 

Is anyone familiar with these Carbon Drive belt systems? I have a customer who is considering this option and i am looking into it but I was wondering if anyone has experience with them, pros & cons, etc. Are they any more trouble than a regular chain driven setup, wear out faster, or harder to maintain, things as such. Any info is greatly appreciated. Thanks

You have to make the drive side seat stay removable so one can replace the belt.
The belt cannot be separated like a chain can.

Yeah, I realized that from the website but what I was wondering is if this thing functions as smoothly as they advertise or is it a headache in disguise. Making an entrance for the belt is not my main concern, the main concern for me is if this thing functions well. I guess you could always convert it back to chain driven.

I think the only difference from the framebuilder's viewpoint is the break in the frame for the belt. As you say, there is no reason you can't run a chain on a frame that is belt capable. There are some people that really say horrible things about the belt drive, I'm not sure where the truth lies. I'm still interested myself, although chain drive is hard to improve on. I'm still interested for commuting mostly.

I tried to get a carbon drive system for Rohloff, but gave in and got a chain system instead. Attitude amoung those who had tried it was that it had a high cool factor, but little real advantage, however, little real problem either. Slight higher resistence but not significant. All the usual problems with resupply that one might have with any unconventional product.

Based on results in the motorcycle world, it would be less maintenance and less wear. No requirement to clean or lube it, and they last longer than chains.

check out this link for an update to how belt drives are being done:

http://www.carbondrivesystems.com/fo...rs.php?lang=us

I built up this commuter using a Lynskey 'Crosstown' frame that was on sale.

Belt is quiet, clean and maintenance free. It needed to be re-tensioned after the first 100km or so, but this was easy (ie loosen wheel, pull back, tighten).

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Frame has a joint on the rear seatstay.

Braze on is not in an ideal location on chainstay for a neat/traditional cable routing for an IGH, hence loop of cable.

Versa 8 shifters go up well, but not so good shifting down. Not sure if this is the nature of the Nexus hub, my adjustment skills, or something to do with the shifter.

Brakes suck. Cantis were squeeky and lots of fork shudder. V-brakes are a bit weak at the moment as I don't have Travel Agents on them (on order). If the fork had a mount on it I would have put the cable guide there for the canti brakes. Disk would have been better, but frame not set up for that.

In my very limited experience it's a neat idea, very smooth and silent, but with very noticeable resistance compared to a chain. It may have been that the belt on the one example I tried was too tight - it was very tight, but I was told that was normal - but if the level of resistance I noted was typical, then I would limit their application to upright city bikes where the rider just doesn't care. On any sort of performance bike, I would find it (spin the wheel by hand and watch it grind to a stop in a couple of revolutions) unacceptable.

Motorcycles make use of both belt and chain drives. Most Harleys have belts - most sport bikes have chains.

Chain are usually more efficient - belt quieter and less maintenance and last much longer (x3-4). My next motorcycle will be belt...

For relaxed bicycling I think belts make a lot of sense. Not so much for racing ..

Cheers

That is an email I received from the maker of this bike. I had emailed him when the bike had first surfaced a few years back as I was thinking of trying to make my new build a belt drive.

For cost reasons I didn't, but since then I've also ridden a trek belt drive bike at the lbs. Didn't have my license with me, so only got to ride it around the store a few times. I felt no noticeable difference in the ride except the coasting which I'm not used to. The acceleration from 0 to like 10 (in a store remember) felt normal, the resistance seemed the same, it was quiet, it was dry (no lube).

I'd still like to build up a belt drive bike. Ideally I'll build a bamboo frame soon and put one on that. Even if there is no performance difference, it's novel and neat, and that is worth something at least to me.

I'm making a bamboo/wood belt drive mtb right now. I'll post some pics soon.

I'm wondering how that would be done. Would it be a simple matter of cutting out a piece of the seat stay and making some sort of coupler? Would it be a screw together coupler? Or a sleeve of some sort?

I'd like to think I can take my current Trek 520 frame and do this modification (or have it done), in order to convert to a belt.

Anyone?

I wonder if a smaller variant of a S and S type connector could be fitted on the chain stay...

I've seen one single S&S coupler on a seatstay -- undo it and simply spread the stay barely wide enough to get the belt through. Also, a couple different systems with some kind of bolt(s) holding the chainstay together at a break for the belt by the rear dropout.

I work in a Trek shop and have to deal with belt systems on a semi-regular business. Most of the issues are noise related -- people expect dead quiet, but if alignment or tension is off, there will be noise. PITA figuring various objectionable noises out and fixing them.

Also, frame flex is an issue. There's a couple of carbon SS Superfly 29ers with belt drive out there and users have had issues with belt slippage and belts coming off usually the rear cog under high torque situations.

Builders should also keep in mind that cogs and belt-rings are much wider than their chain drive counterparts which needs to be taken into account around places like the bb/drive side chainstay, especially considering alinment between front and rear cogs, i.e. belt-line has to be near perfect.

More headaches than benefits IMHO...

I just had my son build up my "Forever Bike" with Rohloff hub and Gates belt drive. just took deliver of it and so am anxious to try it out. it will be by ultimate commuter bike. http://pushingthepedals.com/2011/05/18/dads-new-bike/

The other approach could be to figure out a way of mounting the rear cog on the outside of the stay. Different frame design. Also requires different rear hub components.

Thank you for that post Mconlonx!

Hmmm. That's a thought for a design frame engineer. If they could create a wheel/hub and frame that works together, almost like the rear frame member clamp onto and hold a caged bearing and the axle could spin inside with the rear cog outside of the stay? Maybe really narrow stays? Out of my league though...

Belt drive in my opinion sucks !!!! may i say NOISE and slippage , bout a 2011 district carbon went to a chain drive & now perfect ( no wonder the chain is well over 100 years old ) Trek was nothing but good in helping me they tried everything and included new everything as far as drivetrain to try to fix it :)

It'd be easier to build the frame with elevated chainstays:

http://www.firstflightbikes.com/_borders/MantisXCR.JPG

Yes, ad an EBB or sliding dropout to one of those elevated chainstay things,
and It would be simpler..

even like the Alpine Stars frames, they only elevated the drive-side ..

and yes S and S machine shop does make small diameter connectors.
there are several other ways people have managed the split.


personally I would like to see a covered drive train, in the Dutch tradition,
one of stretched truck tarp on a wire frame.
covering the Belt drive,
since they still would eat trouser legs, so covering them fixes that .

and a covered chain drive, out of sight out of mind, rarely gets oiled.

If the Belt drive were hidden It could be ignored , to no problem.

but its still in the gee whiz look at what I did stage now

maybe as a mature technology the practical will begin to adopt the parts.

My mind is made up re. the belt drive, but I am interested in hearing how the Rohloff works out.

Some links for sliding, Rohloff compatible dropouts etc that you could use.

http://blog.ahrensbicycles.com/2009/...onversion.html
http://www.paragonmachineworks.com/s...-261333-2.aspx

I'm almost done with my Rohloff frame, using the Paragon drops. Just waiting for the wheel to get here so I can get the bridges the right distances for fenders.