Would it be possible to run the rear sprocket parrallel/outside of the rear triangle? Or would that put too much stress on the the rear dropouts/QR on the non-driveside?

"I'm not sure I can be arsed with changing a belt every 10 to 20 years on my bike. "

:DYou mean you haven't clocked up that mileage this year month 😉

My point was less about the longevity of the belt and more about why we have to change our chains periodically compared to cars – guess it's the twisting of gear changes and the grime…

To answer a couple of questions, being the OP.

Tension is much lower than I expected. About the same, or less, than I'd run a single speed chain. I could easily slide the belt from the rear sprocket (not that it's a recommended way of removal) so I'd not expect any extra bearing wear over a chain.

The gates website has a video on how to handle the belts and not stress the carbon fibres that run it's length and all but eliminate stretch (apparently).

Tension is achieved using the eccentric bottom bracket.

As far as weight goes, it's about the same as my Scott Scale RC, which is also a Rohloff equipped bike. Sorry to be vague but I don't have an easy way to weigh them.

On a side note (and this may be just my imagination), Rohloffs are often criticised for being noisy. I don't know if it's the Ti frame or the carbon drive, or both, but this Rohloff seems so much quieter than my other two. Maybe it's a resonance thing.

If anyone wants to know more about the bike or buying from Van Nicholas then drop me an email.

IanW – Member
Cant really understand why people are negative towards belts

There's a lot more internet acquired expertise out there than practical experience with a belt 🙂

Nicknoxx – Member
…Lynskey 'refused' to fit a split dropout for belt drive saying they would not be able to warranty the weld on the chainside dropout/chainstay.

That's odd. I've seen a photo of their conversion and it was neat – similar to the Zion. If they can't warrant the weld at a pin joint, I would be a bit anxious about the rest of their welding.

Rip – Member
…Tension is much lower than I expected…

Gates say to allow up to 2mm for tensioning. I'm using 0.5mm and finding it adequate and a similar to a SS chain. I suspect you would need the whole 2mm if you had a bike with laterally flexy chainstays. Of the bikes I have converted, 2 were done with no provision for adjustment, and just with dropouts placed to provide the 0.5mm tension.

On the noise thing I'm not surprised that the belt is quieter. I've always found my Rohloff at it's loudest after re tensioning the chain which making me think that it is the tighter chain that transmits more noise from the hub into the chainset then into the frame. A bit like two tin cans and a bit of string.

The maintenance advantage for me is actually less of an incentive than the weight advantage. My last cheap Sram chain lasted 3 years and was still working fine when I changed it. The current KMC 3 speed chain has been on for a year and is coping with my high maintenance schedule of wiping it occasionally and squirting some GT85 on it. This is a bike I use as an all year round off road commuter.

Anyway if I could have any bike I've seen on these forums it would be this one.

Cant really understand why people are negative towards belts, anything new I suppose.

it it just scepticism ? We know chains work about adequately in MTB conditions – there are still questions about increased bearing sideloads and mud/stone resilience with a belt.

OK, I'm reading this with interest. So you need a modified frame; you have to settle for either single speed or go for an expensive hub gear system with a limited range; you can't use it on a full suspension frame; and when it wears out (which it will) it costs £250 to replace.

I've heard about a system that works on all frames, hard tail and full suspension; is cheap to replace and parts are readily available; and it accomodates an absolutely massive range of gear ratios – as many as you will ever need. It was invented in the 19th century and apart from various fine tuning and development, ramains largely unchanged since the 1930s.

It's called the 'chain and deurallieur'.

Wayyyyy different I guess but I had a Strida folding bike with a belt – supposedly good for 60,000+ miles. I think my first one lasted about 200 miles before snapping. And that was on a gentle commute from the office to London Bridge station…

http://www.best-motorcycle-gear.com/motorcycle-transmission.html

Ooh that's nice. If they did a 29er I'd seriously consider buying one.

Regarding the 60k cam belt change. That's 60000 miles at an average of what, 30mph at 5000rpm ? How many revolutions is that ? Probably more than you'll ever pedal in your lifetime. And cam chains run in an oil bath anyway.
A more realistic comparison would be the belt drives used on Harley Davidsons. They've been around a few years and have proved reliable.

There's an interesting discussion on belt drive Rohloffs on the Thorn forum.
http://www.thorncycles.co.uk/forums/index.php?topic=2266.0

MilitantGraham – Member
A more realistic comparison would be the belt drives used on Harley Davidsons. They've been around a few years and have proved reliable.

It would if people rode Harley Davidsons through axle-deep mud, without mudguards etc. Harleys are built mostly for the US market where grit, mud and rain aren't so much of a problem. Motorcycles that are built for more demanding climes are usually chain-driven.

Quiver = windsurfing schpeak…

And surfing…

Cool looking bike in your "stable!"

Good point, Shibboleth, I suppose an even more realistic comparison would be motocross bikes, but as there are no belt drive MX bikes, as far as I know, we can't make that comparison.
I guess I'll have to let Rip and other pioneers gain some long term experience before I commit to buying a new frame and £250 worth of belt and pulleys.
As far as new technologies, or established technologies in new applications, go though, it's looking pretty good so far.

Shibboleth – Member
…It would if people rode Harley Davidsons through axle-deep mud…

I used to, and that's why I am convinced belt drive is good.

Chains and derailleurs are fine for their purpose.

But there are people who run single speed or hub gears, and belt drive is superior for that purpose.

BTW the Strida uses a different belt AFAIK

Epicyclo

Gates say to allow up to 2mm for tensioning. I'm using 0.5mm and finding it adequate and a similar to a SS chain. I suspect you would need the whole 2mm if you had a bike with laterally flexy chainstays. Of the bikes I have converted, 2 were done with no provision for adjustment, and just with dropouts placed to provide the 0.5mm tension.

I think you may be overdoing the tension a bit there.

The Gates manual says:
b. Checking tension by hand: Applying 5 lbs to 10 lbs of pressure on the center of the belt span, the belt should deflect about 1?2-inch. (For detailed tensioning instructions, please review the Tension_Requirements.PDF document)

…unless I'm misunderstanding the manual.

Rip – Member
Epicyclo … I think you may be overdoing the tension a bit there.

Ah, I should have made it clear that I was talking about along the chainstay length, not the usual vertical at midpoint method.

MilitantGraham

Ooh that's nice. If they did a 29er I'd seriously consider buying one.

They do! no excuses now 😉

Where did the £250 replacement come from? At VN a replacement belt is €60.

Gates quoted me £250 for two cogs and a belt.

ouch

Gates quoted me £250 for two cogs and a belt.

The thing is until we find out how long these last in the real world we won't know if that's expensive or a bargain.

That's very interesting, Nicknoxx, particularly given that on this MTBR thread you can see a Pro29 specced with a belt drive!

I suspect they didn't want to change the design as I only introduced the idea of a belt quite late on (see below)

How's your delivery coming along? I am having a Ridgeline 29 tweaked to take Rohloff neatly, adjusting cable guides and suchlike. Quoted 7-8 weeks, 15 weeks later and still no sign of a frame… uber-relaxed customer service, i.e. lacking in detail.

My first contact with Lynskey was in January it took until the end of May to get a final drawing with only three revisions (I'd supplied quite a detailed drawing initially) It's now in production. I told them right at the beginning that my 50th birthday was at the end of July and it had better be ready by then. Nice guys and quite helpful but they're too busy to communicate effectively in my opinion.

This is the drawing of my dropout
Lynskeys comment was:-

We will not be able to warrant this frame against any breakage on the dropout when adding the split drive-side bolted stay for carbon belt drive. Because of the design and size of the dropout, there will ultimately be too much torque and stress on the single weld specifically at the chain stay on the drive side. And with our experience an eccentric bb doesn’t allow enough adjustment to get the proper belt tension as specified by Gates Carbon – that is the reason for a slider style drop-out allowing 7.5 mm of tension adjustment.

Rubber is uber tough, much less brittle than metal. It's much more elastic than metal so it wont lengthen. Should hold much less crep, needs no oiling and will clean easily. Also, you aren't shifting it so that in itself will improve reliability and reduce wear over a conventionally geared bike. Hopefully, changing belts will be very infrequent, perhaps 10,000+ miles.

Am very interested in your results of running it throughout next winter.

TheSwede – Member

Gates quoted me £250 for two cogs and a belt.

They quoted me the same when i asked about converting the timing chain on our tandem.

They also said that it would only be good for "leisure" riding as the power from two people cranking hard on an offroad tandem would make the belt slip.

They also said that it would only be good for "leisure" riding as the power from two people cranking hard on an offroad tandem would make the belt slip.

Surely only the rider at the front puts any load on the timing chain/belt

Surely only the rider at the front puts any load on the timing chain/belt

I'm just repeating what they said.

Having looked at the way the stokers chainring gets worn on both sides of the teeth though I'd have to agree with them.

If you want to give me £250 to buy the bits with though I'll fit them and tell you what happens. 😉

Nicknoxx, I remember seeing an earlier picture of your frame design a few months ago; that really is a beautifully designed dropout. I hope that it is delivered and built on time for your 50th, a stunning present.