Gates "Surefit" sprockets for belt drive bikes
 

I guess this has been around for a while, but I just noticed that Gates now sells a new rear sprocket called "Surefit" that features a new design that makes the sprocket fit flush with the Nexus/Alfine hubs. The biggest (and probably only) problem I've had with my carbon belt drive train is a clicking noise that results from the sprocket not interfacing well with my Nexus hub (there seems to be a small bit of play between the two components). I wasted countless hours trying to chase this noise down only to find later that the answer was already on Gates' FAQ page along with a remedy: wrapping teflon tape around the hub-sprocket interface. The tape method seems to work, but I've found that I have to periodically re-wrap the interface with fresh tape to keep it quiet. Looks like they made this new sprocket specifically to address this issue. Has anyone tried one of these yet?

http://www.carbondrivesystems.com/~/...t-13-03-28.pdf

Interesting, change , but No, I dont have any bikes with a belt drive at all ..

Rohloff, chain driven, cost enough ..

SureFit design
 

I know it's a bit of an archeology, but I was trying to find information about this whole SureFit thing and it looks like it's about a way the sprocket locks on the driver. It doesn't use additional circlip, but instead it's those 3 spider-like lobes which come into a circlip groove. I don't have any experience with it, so can't tell you if they fixed a bad fit issue with these, but, since they still produce standard 3-lobe sprockets, my guess is that it's only about assembly. It'd best to check how a sprocket fits driver while buying a new one, since both hub and sprocket are made with some tolerance regarding dimensions and one can fit better than other. Hope I helped and hello to everyone, since it's my first post here :).

I will say that any two drive elements should NOT have any play between them. The sprocket should lock onto the hub very snuggly. Others have had this problem (see video). For possible solutions, see the comments. One person suggested that you need a different retaining ring. Others suggest that the wiggle is normal but is a design flaw: the steel and aluminum will wear prematurely.

Gates sells a "Surefit Installation Tool". Seams pretty complex... https://www.gatescarbondrive.com/~/m...arch.pdf?la=en

I looked through some Gates' documentation and they indeed boast that the fit is better with this new design. They also write that "Note: NMN sprockets are no longer recommended for Shimano and SRAM 3-lobe hubs. Use XMN sprockets for optimal performance." (NMN is the standard, "Sturmey Archer" 3-lobe style sprocket, XMN is Surefit).