This should make it possible to run a belt on flexy chainstays. More detail here

How? It just looks like a better belt drive – I thought the issue was that the stays had to be stiffer to stand being split?

tron – Member
…I thought the issue was that the stays had to be stiffer to stand being split?

No, the stiffness is needed to stop the belt arriving at the rear cog misaligned and then riding up on the cog. This system should be more tolerant of flex.

Of course, the proof of the pudding etc. I'm trying to source one of the samples, so I'll be able to check this out.

I am guessing the slots/teeth stop it jumping.

Don't see why stays need to be any stiffer to handle the split – most joints I've seen don't look any flexier than the stays (and it's usually the seatstay that is split no?)

That certainly looks like it solves any mis-alignment issues.

As regards split seatstays/dropouts, maybe I'm missing something but aren't a lot full suspension bikes effectively 'split' where they pivot?

Just looking at a picture of an Orange ST4….

travellingman – Member
…As regards split seatstays/dropouts, maybe I'm missing something but aren't a lot full suspension bikes effectively 'split' where they pivot?

It is not an issue. Lots of bikes have a split at the seatstay/chainstay.

Anyone who has carbon seatstays on an alloy frame probably has a neatly concealed pin joint where the caborn meets the alloy.

The flex issue with belt drives is the lateral flex in the chainstay.

…and belt drives don't work on FS bikes (unless pivoting around BB)

How would mud/crud clear with this system?
With the other type it is supposed to push through the holes in the ring.
edit – oops I can see it now 🙂

cynic-al – Member
…and belt drives don't work on FS bikes (unless pivoting around BB)

I think it may work on something like an Anthem which has very little chain growth. Just run a bit of slack in the belt (and use a snubber if necessary). After all there are plenty belt drive motorcycles whose swing arm pivots are not concentric with the drive cog. I'd be more concerned about play in the pivots allowing misalignment under stress than a little bit of slack.

Epicyclo: you can't run slack in with Gates drive – tension needs to be high to prevent the belt skipping.

Schlumpf were showing an alternative (but one that works only with their Schlumpf drive cranks) at Eurobike. They've got an English Pdf doc up now that explains it (German only when we visited the Eurobike stand).

simons_nicolai-uk – Member
Epicyclo: you can't run slack in with Gates drive – tension needs to be high to prevent the belt skipping.

I know they say that.

I do not use the recommended high tension. I run my belts at the same tension as my singlespeed chains and do not get any skipping. That way I don't have to worry about damage to my BB or wheel bearings. I am very particular about alignment though.

I have yet to see any impact on belt life on any of the bikes I've built with this system.