I am afraid i am not seeing what you are seeing. the belt starts on the outside of the stays, and passes through the right seat and chain stay to the rear cog yes? since belts are sold as a belt, there would need to be somewhere in the right chain stay, seat stay, seat tube triangle where the belt can pass through. I am not seeing one. Can you point one out for me?http://farm4.static.flickr.com/3157/...ff5e1c.jpg?v=0

http://farm4.static.flickr.com/3239/...527fab.jpg?v=0

unless in that bottom picture, the seat and chainstays are not welded, but bolted together with that black thing.

then i stand corrected

Look at the dropout. It is bolted to both seat and chainstay. Pop it off slide belt through and bolt back together.

yeah, you can see it more clearly here

http://www.trekbikes.com/images/bike...intagegray.jpg

Yeah my only concern would be how hard is it to tension the belt correctly.... I wonder if you can do it yourself or not.

Is that a Passat W8 or a Phaeton/A8 W12 engine by any chance?

You don't have to. The parts are already in production, they have been for years. The crankset/cog/hub combo on the show bikes are identical to those used on tens of thousands of Japanese commuter bikes. There's one parked outside the grocery store across the street as I write.

This is not new technology.

i have pics of a W8 with the heads off somewhere on my laptop. as far as i know the W12 is bulletproof. one has never come out in my shop and we are the highest service volume dealer in toronto.

Tens of thousands of Japanese are commuting fixed with a belt-drive? Please link me one purchase-able belt-drive rear fixed cog.

Check this link out. This would easily work if you wanted to retrofit or build a frame around a belt drive, well, maybe not easily work. You would have to do some major measuring, cutting, and brazing. Probably best left to the pros, but it's an option.

http://www.sandsmachine.com/spec_ssc.htm

Ahhh, I was trying to remember what those things are called - they call them 'Bicycle Torque Couplings' on that page, and I think that would be a damn near perfect solution. (EDIT: although it may be far beyond what the OP wanted to do)

I also don't think it would be that difficult to do. You could even have some beautiful lugs cut into those couplings - see http://www.sandsmachine.com/carvlugs.htm

These are made for top/down tubes.

Could just hack your dropout and make some bolt-on backing plates for like $.50 and a few minutes work. Tubes should flex enough to squeeze a belt in.

IMO, not worth the effort or safe.

http://img377.imageshack.us/img377/3...2751xp0.th.png

^^^^^^ Disclaimer: do not do this. you will die a horrible death. *For visualization purposes only.*

my question exactly...

ok, new plan.

I'm getting the District. I'm excited for a maintenance free, super reliable, clean, smooth and comfortable ride for my commute. I love it for this purpose. Gonna drop the Fixed gear idea for now until parts are available. Its just too new it seems and I dont want to compromise anything. But I have seen these concepts (Fixie Inc, Spot is coming out with one soon) and the part will come.

And I'll just start a project bike and build a regular ol' fixie for fun.

I was googling and found this too:
http://waltworks.blogspot.com/2008/0...-thoughts.html
He's a framebuilder who got some parts from Spot. It looks like it's not too far off. But not quite here yet.
http://bp0.blogger.com/_5ZOmYbeW-EM/.../s400/CDS1.jpg
It might be possible to use a front mountain disk hub and drill out the rear belt cog? maybe? I'd e-mail that guy if you're really interested.

oh thanks! his initial insight is really interesting.... i'd love to see this develop.

Retrofitting could be possible if you're into welding.

If it's over a year old, kinda silly to bump it. But welcome to the forums.

Regardless of how you feel about belt -Vs- chain.... chain is THE standard. Going with a belt drive bike is like choosing beta when everyone around you is going VHS. Personally I'd rather go with the standard, so everything is easier. ...getting parts, working on it, upgrading or swapping things out. Belt drive locks you into something that almost nobody uses.

Hey, did you advertise on this site a few years ago?

I did! :) Back when I was just starting out.

Thank you for supporting the site, back when it was not corporate owned. If you have a 125x125 banner, I'll run it on my blog.

I rode a Trek Soho and I hated the acceleration feel due to it being belt driven. Acceleration from a stop was mushy and no where near as crisp when driven by chain. Granted that the Soho is not a fixed gear I would only imagine it would be worse for fixies to be belt driven as you'll be also using the drivetrain as your brakes. So IMHO, do NOT go with the belt. Stick with the standard chain.

http://vonrafael.com/en/concept-hd.html
http://vonrafael.com/img/concept-hd0.jpg
This cost 5000 euro's and it uses a belt drive. Granted the bike is way overpriced, but it would seem to prove a point. If a formula 1 engineer builds a bike that cost that much, and chooses to use a belt drive, it must be a pretty good system.

I am going to build a carbon fiber frame and have been seriously considering building it to accommodate a belt drive system, but now I am going to have to test ride one of these things first. One of my lbs has a trek sitting in the window that I'll check out tomorrow

And looking for more info about belt drives, it seems that now they will be offering them fixed. Fixie inc has just developed a flip flop hub for belt drives
http://road.cc/content/news/9520-fix...lt-drive-bikes

"If a formula 1 engineer builds a bike that cost that much, and chooses to use a belt drive, it must be a pretty good system."

Or it's just overpriced wankery to appeal to the non-cycling crowd, a la the Porsche mountain bike or the Lamborghini hybrid bike.

If you want "look at me" points (and this is not an inconsequential factor in any custom build), and you're willing to retrofit a seatstay to accomodate it, and can find all the unique parts (I just tried google, not having much luck finding belts or cogs or chainrings), then sure, belt drive is the way to go.

If you want practicality and cost effectiveness (e.g. being able to walk into ANY bike shop and find replacement parts), then go with a chain.

If you want "look at me" points AND practicality, get a track chain in purple for $8 and call it a day.

(If you can find the actual belt drive parts, please post up here, as it would be interesting to see what a belt drive drivetrain goes for.)