We recently brought you news of Orange's belt-driven prototypes. But Orange isn't the only manufacturer working on belts. Spot is working with the same belt manufacturer, Gates Drive Systems, and is fully embracing the technology - it showed up at Interbike's Outdoor Demo with 30 belt-drive mountain and cyclocross bikes and one chain-driven one (that languished unridden for the whole two days).

Spot's belt is the same construction as Orange's, but with a slightly different tooth profile. It runs on Teflon-coated aluminium pulleys with open tooth beds to allow dirt to get squeezed out. To allow belt replacement, Spot has devised cunning split dropouts with a keyed insert.

The bike we rode was a 29in-wheeled singlespeed MTB (Spot is working on a geared solution, but for the moment it's looking at singlespeeds only). We were mainly interested in the belt drive so we'll not say much about the whole 29er thing. For the record, though, the Spot felt like, well, a bike, albeit one on the long side...

The belt delivered a super-smooth and almost silent ride - the Nevada dust caused the occasional "chirrup" noise, but a squirt of water made that go away. Combined with the rapid take-up of the Chris King rear hub, drive was immediate, with no sign of stretch or slip.

We'll have to wait and see how it fares in the mud, but testing carried out by Spot and the belt manufacturer suggests pretty reasonable transmission lifespans - they're talking of a couple of thousand miles for the pulleys (with the fronts lasting longer than the rears) and tens of thousands for the belt.