Just wondering what the benefits/drawbacks of belt drive are on a bicycle, thinking perhaps in a Rohloff setup. A good winter solution?

I'd love to try it. It's supposed to be silent, long-life and maintenance-free.

Drawbacks are the initial cost of the specialist kit, and you need a split in your rear triangle somewhere. And it's not recommended if you ride in serious filth.

Kit: http://www.carbondrivesystems.com/

Good bodging: http://www.flickr.com/photos/34903211@N02/sets/72157624060602242/

Drawbacks are the initial cost of the specialist kit, and you need a split in your rear triangle somewhere. And it's not recommended if you ride in serious filth.

Not really MTB suited then eh!

Harley Davidson seem to make it work.

I'm thinking of trying a belt drive on the timing chain on our tandem.

if it's basically no maintenance, is there no way to enclose such a system for mtb use?

Are the belts long enough for that, Stu?

since when was a Harley ever ridden in serious filth?

if it's basically no maintenance, is there no way to enclose such a system for mtb use?

Sure, if you want a nice large tin box round your right chainstay. 🙂

Cheers Simon, looks interesting. I wonder if there are any drag issues associated with these belts and the high tension they appear to require. I'd also worry about having a split in the seatstay, from a rigidity point of view. The belt concept is attractive though.

was thinking more cf than tin tbf and not necessarily a shopping bike style casing 😆

Why enclose it if it's zero maintenance?

This wonderful thing is what got me thinking about it.

I might be wrong about the mud:

"What about mud?
The Carbon Drive System functions beautifully in mud. Read the testimonial from Steve Fassbinder"

But I'm sure I read somewhere else that it can be bad news. Obviously the dirt will accelerate belt wear, but they're not killer expensive although are only supposed to last "more than twice" as long as a chain. 6 months then…

On motorcycles BMW use them a lot on the smaller bikes – but not on the offroad versions as a stone getting caught between the belt and sprocket will break the belt and no trailside repair is possible. However this may be theoretical rather than something that happens with any frequency and a cyclist may well not have the power to break the belt – it would just jam perhaps.

simon1975 – Member

Are the belts long enough for that, Stu?

I'll tell you when Gates get back to me.

I wonder if there are any drag issues associated with these belts

There was a big discussion about that over on mtbr some time ago. Various claims were made but I seem to remember that generally they are 80-something percent efficient at transfering power, as opposed to 90-something for a good old-fashioned chain.

cynic-al – Member

Why enclose it if it's zero maintenance?

well i'd heard bad shit goes down if you get stones and the like in the system. have no experience of them at all though…

I wonder if there are any drag issues associated with these belts
There was a big discussion about that over on mtbr some time ago. Various claims were made but I seem to remember that generally they are 80-something percent efficient at transfering power, as opposed to 90-something for a good old-fashioned chain.

Cheers, but then of course unless you're SS'ing, you'd be looking at an internal geared hub, losing some more efficiency versus a regular chain/dérailleur setup. Hmm. Liking the concept but can't quite see the benefit just yet.

If it lasts twice as long as a chain with a Rohloff then I should be able to get 6 years from one belt! One other advantage for hub gear users is that the belt system weighs a lot less than a conventional chain, chainring and sprocket reducing the overall weight penalty of using a hub gear. At the moment Rohloff are saying you can't buy an after-market system and that it has to come as part of a complete bike but I think there are ways round that if your not worried by warranty issues. I'd love to try it but I do ride all winter in very muddy conditions so I'd have to be pretty sure it was going to handle that. Another issue is the lack of frames that are currently avaliable. Van Nicholas do a belt version of the Zion frame which I'd rather like and I think it's a shame that when ibis designed the tranny to be a multi-use bike they didn't think far enough ahead to allow it to work with a belt drive.

Yeah I'm thinking about this in the context of a custom frame design.

My VN belt drive Zion is on order. 10 week wait though!

Thought I'd give one a try as I like anything that's a bit different. I've just ordered the frame and drive. I'll build the rest up myself. And it'll be my first Ti bike.

To allow the belt to be fitted (to steel frames at least) Shand have some info:

CarbonDrive beltdrives

Just added that Shand site to my favourites.

Rip it will be good to hear how you get on with the belt drive. I think there are a few on here who have been waiting for someone to go what the hell I'll give it a go. I know I have. And even if you don't get on with the belt drive in the mud you can always run a conventional chain for the winter. It should be a pretty simple job to swap.

Speaking as an experienced belt drive bodger…. (Thanks for the compliment Simon 🙂 )

AndyRT – Member
since when was a Harley ever ridden in serious filth?

Mine were in Oz. Long distances on dirt roads including the wet season. Just don't let the mud dry 🙁

pedalhead – Member
Cheers Simon, looks interesting. I wonder if there are any drag issues associated with these belts and the high tension they appear to require. I'd also worry about having a split in the seatstay, from a rigidity point of view. The belt concept is attractive though.

No noticeable drag. Seatstay splits should not be a problem. Almost all bikes other than sports bikes used to have a bolt on seatstay. There's a good 100 years of troublefree use to look back on. Also if you look closely at many bikes with carbon seatstays you'll notice a well concealed joint.

Rigidity of the joint is not a problem if it is properly designed. None of the joints in the conversions I have done have budged. The oldest is 18months old.

TandemJeremy – Member
… but not on the offroad versions as a stone getting caught between the belt and sprocket will break the belt and no trailside repair is possible. However this may be theoretical rather than something that happens with any frequency and a cyclist may well not have the power to break the belt – it would just jam perhaps.

The chances of that happening on a part that is vibrating like mad is about the same as it happening with a chain. When did you last disintegrate a chain with a jammed stone? A spare belt is lighter than a chainbreaker tool if it bothers you.

At the moment Rohloff are saying you can't buy an after-market system and that it has to come as part of a complete bike but I think there are ways round that if your not worried by warranty issues.

The Rohloff pulley (sprocket) comes in 2 parts. The pulley itself and the carrier. The carrier fits to the hub and replaces the carrier that normally handles the chaindrive sprocket. The beltdrive pulley then fits to this. You need to get Rohloff to fit the carrier. One of the primary hub seals is also part of the carrier which is why Rohloff want to do it themselves.

Rohloff will only do this to hubs going on to frames that have passed a stiffness test. This is to make sure the frame doesn't shift around throwing the chainline off.

shand, i'm guessing you don't have the ability to put the couplings in an alu frame?

avdave2

Rip it will be good to hear how you get on with the belt drive. I think there are a few on here who have been waiting for someone to go what the hell I'll give it a go. I know I have. And even if you don't get on with the belt drive in the mud you can always run a conventional chain for the winter. It should be a pretty simple job to swap.

That was my thinking too. I run two other Rohloff bikes so have all the bits to make a swap. However, I fully expect it to be fine for the riding I do.

I'll be posting pics as soon as I get it.

Thanks shand that's useful information and rules out my idea of easily going back to a chain if it proves to be unreliable in very muddy conditions. So as my Rohloff is v brake only I could be looking at some serious money to upgrade it to both disk and belt drive compatible.

shandcycles

At the moment Rohloff are saying you can't buy an after-market system and that it has to come as part of a complete bike but I think there are ways round that if your not worried by warranty issues.

The Rohloff pulley (sprocket) comes in 2 parts. The pulley itself and the carrier. The carrier fits to the hub and replaces the carrier that normally handles the chaindrive sprocket. The beltdrive pulley then fits to this. You need to get Rohloff to fit the carrier. One of the primary hub seals is also part of the carrier which is why Rohloff want to do it themselves.

Rohloff will only do this to hubs going on to frames that have passed a stiffness test. This is to make sure the frame doesn't shift around throwing the chainline off.

That makes interesting reading.

When I spoke to Van Nicholas before ordering, I was told that Rohloff don't condone the belt drive at all and won't support it.

When I asked about the warranty of the hub they said you just remove the driven pulley and fit a sprocket before returning it. Nothing about modifying the hub.

Someone has the story wrong.

My understanding from Rohloff was that they did support the belt drive but only on units they had supplied to manufactures and that you could buy the complete bike or frame and drive kit but not the individual components. In fact the carbon drive website has a link to a press release on the Rolhoff site IIRC. It does seem that there needs to be some clarity on this and I can understand your concern Rip if you find yourself in a position where you can't swap back to a chain drive.

all you need is horizontal dropouts…here you go…

heres one used offroad belt drive

My understanding from Rohloff was that they did support the belt drive but only on units they had supplied to manufactures and that you could buy the complete bike or frame and drive kit but not the individual components. In fact the carbon drive website has a link to a press release on the Rolhoff site IIRC. It does seem that there needs to be some clarity on this and I can understand your concern Rip if you find yourself in a position where you can't swap back to a chain drive.

Just to clarify. The pulley comes from Carbon Drive and the carrier comes from Rohloff. When I place an order with Carbon Drive for pulleys and belts, the front pulleys and belts comes to me directly, the rear pulley is sent by CD to Rohloff to be fitted to the hub. Rohloff build the hub with a compatible carrier for the belt drive pulley, they fit the pulley to the carrier on the hub and send it out to me. They'll only do this for manufacturers/builders that have passed their testing.

You can certainly send your beltdrive hub to them and they'll swap out the beltdrive carrier to a chaindrive one to enable you to switch back. I think they'll even send you the chaindrive carrier and you could do it yourself but that would void the warranty I believe.

shand, i'm guessing you don't have the ability to put the couplings in an alu frame?

Nah sorry, you're on your own with that one!

That makes interesting reading.

When I spoke to Van Nicholas before ordering, I was told that Rohloff don't condone the belt drive at all and won't support it.

When I asked about the warranty of the hub they said you just remove the driven pulley and fit a sprocket before returning it. Nothing about modifying the hub.

Someone has the story wrong.

They've got it wrong.

linky

Rohloff are very concerned that anybody doing this are doing it properly. It only takes a few bodgers to **** things up and post horror stories al over t'interweb and the whole concept can be shafted. It's true that Rohloff only recently came onboard and I believe there were some early prototype pulleys designed to just replace the existing chaindrive sprocket. I'm not even sure these were Rohloff/CarbonDrive components.

Feel free to get in touch if you need more info.

Cheers

since when was a Harley ever ridden in serious filth?

http://www.earlyyearsofmx.com/HarleyBaja100.html

it was though voted one of the 10 worst bikes ever made though!! 😀

Anyone tried the Gates fixed sprocket? I'd be interested to hear if the belt buzzes under braking forces at speed, and if it feels secure when you put it into a skid. I've seen some stuff on London FGSS so I know it's been done!

since when was a Harley ever ridden in serious filth?
http://www.earlyyearsofmx.com/HarleyBaja100.html

it was though voted one of the 10 worst bikes ever made though!!

the eagle eyed viewers will notice the mahoosive rear sprocket and CHAIN. 😉

Are spare chainrings (beltrings?) available or are you stuck with what you have … ?

When I build an SS .. I usually play with cog/front ring combos to get the best ratio for the bike's purpose .. It would be a PITA if you didnt like your ratio and couldnt even change it!