Belt drive fixed

Got sent this by a nursery member... I couldn't find a belt drive thread, so here you go:

Hi Velocity boy, don't know if the community on London Fixed-gear and Single-speed would be interested in this, but they might. It's one of Fixie incs prototybe bikes running a Gates carbon belt drive - they are also experimenting with their frames - this one is bare steel simply coated in olive oil… they also had a stainless steel version, both feature really cool Fastboy Fender wooden bars.

http://road.cc/content/video-fixie-inc-belt-drive-fixed-and-road-irons

I actually love the Pure Blood Cyclocross on that page, but the belt drive is pretty interesting.

i love the idea of belt drive

Looks really cool.

Belt drive is a solution looking for a problem. Lots of the gear geeks on MTBR are getting excited about belt drive MTBs, but even in MTB, where the lack of the need for lubrication means reduced wear, there's no real need for belt drives.

The frames need significant changes to allow the belt to be fitted and the "chainring" is so wide that at least one framebuilder has had problems shaping the chainstays to fir the chainring and allow sufficient tyre clearance. While clearance isn't so much of a problem for a road bike, increasing the q factor to fit the chainring is. The belts only come in a few sizes so you have less flexibility over gear ratios and chainstay length (want to take out a link to tighten up the back end? Tough shit). They only work with fixed, SS or internal geared hubs which really reduces their road market.

What are the advantages? From that link they list:

"belt drive which is claimed to be as efficient as, and last three times as long as, a roller chain" - "as efficient" isn't much of a selling point and with chains at £10-15 a pop I don't mind them wearing out.

It's also up to 300g lighter than a standard eighth-inch fixed setup - save half of that by going to 3/32". I also wonder whether they've taken into account the extra frame weight that the couple adds?

The 953 bike and the cross bike look lovely though.

It's possible progress.

I don't like it.

Belt drive is a solution looking for a problem. Lots of the gear geeks on MTBR are getting excited about belt drive MTBs, but even in MTB, where the lack of the need for lubrication means reduced wear, there's no real need for belt drives.

The frames need significant changes to allow the belt to be fitted and the "chainring" is so wide that at least one framebuilder has had problems shaping the chainstays to fir the chainring and allow sufficient tyre clearance. While clearance isn't so much of a problem for a road bike, increasing the q factor to fit the chainring is. The belts only come in a few sizes so you have less flexibility over gear ratios and chainstay length (want to take out a link to tighten up the back end? Tough shit). They only work with fixed, SS or internal geared hubs which really reduces their road market.

What are the advantages? From that link they list:

"belt drive which is claimed to be as efficient as, and last three times as long as, a roller chain" - "as efficient" isn't much of a selling point and with chains at £10-15 a pop I don't mind them wearing out.

It's also up to 300g lighter than a standard eighth-inch fixed setup - save half of that by going to 3/32". I also wonder whether they've taken into account the extra frame weight that the couple adds?

The 953 bike and the cross bike look lovely though.

It's possible progress.

I don't like it.

perfect summary there tommy!

There are many reasons why belt drive could be a step foward for at least a portion of the bicycle market. Development of the idea doesnt mean someone will come and take your precious chain off you.

Theres someone that I see occasionally with a belt drive tourer, next time Im going to try and stop em for a natter..

How much of that 300g saved is lost to half inch thick cogs and chainrings?

Also, can you fix it should it break while out on a long ride?

Having said that, I am all for people investing time and money in good honest tinkering instead of just following the market.

How much of that 300g saved is lost to half inch thick cogs and chainrings?

Also, can you fix it should it break while out on a long ride?

Having said that, I am all for people investing time and money in good honest tinkering instead of just following the market.

but your chainrings/sprockets can be made of lightweight plastic etc so it would balance out.

In terms of changing the belt, then why not?

Would be far easier to change a dry belt than a dirty greasy chain. Your also more likely to carry a spare as its lighter.

If bike makers used a belt already a standard component in an existing car/motorbike, then it would be extremely easy to get hold of one wherever you are.

Would be far easier to change a dry belt than a dirty greasy chain. Your also more likely to carry a spare as its lighter.

In the absence of a spare, a stocking will do.

Works for fanbelts...

okay, im not working this through a whole lot, but, if they put the reciever for the belt attached to the hub on an elongated spindle just outside the dropout then it would negate the need to cut the seat stay in order to fit the belt, now chainline/beltline may be a problem?? but not untenable... it works in my head anyway, if a bit unseemly... give me chain anyday...

problem is, if you want to try it, you've got to buy a whole new frame so that you can get it on.

i dont see why it cant be done via the hub alone... no need for a different frame...

Well maybe since the hub itself is made for the job they can re-thing spacing at the rear so the beltline(?) would be ok to fit any frame. I suppose they could work on the small problems just like they would have had to originally with the chain. Maybe having the front belt cog(thing) made so it can fit on a normal spider would make it a more realistic idea, also spacing it like a normal chainring.
I could be very wrong about it....

gorgious bike, that fixie inc.

but your chainrings/sprockets can be made of lightweight plastic etc so it would balance out.

In terms of changing the belt, then why not?

Would be far easier to change a dry belt than a dirty greasy chain. Your also more likely to carry a spare as its lighter.

If bike makers used a belt already a standard component in an existing car/motorbike, then it would be extremely easy to get hold of one wherever you are.

Fair points, I obviously did'nt think that through. Would this affect Q - factor?

Love the car-scratchers.

Looks really cool.

Indeed!

Interesting vid about fixie inc belt drive:
YouTube - Fixie Inc belt drive fixed gear bike

repost buddy ;)

ahh....sorry.

We kill you now.

its ok alex, everyone's allowed one.

here's another german solution for a belt driven fixed gear:

www.zahnriemenfahrrad.de

Trek have two OTP belt driven single speeds. The geared Soho and the district.

Still waiting for them to come into stock, been waiting aaaages.. Don't know if the district has a flip flop hub. Both models have removeable dropouts so you can fit the belt.

The fixed gear on that site is very pretty, if a bit ghostbikey.
Does anyone know how a belt would hold up against the pressures of riding brakeless? I'm be loath to try something that wasn't strong enough...
I'm sure it'd be fine, but you know, steel IS real.

Should be OK, Harley Davidson have had bands instead of chains for years, and even you don't put out as much torques as a Harley.