I am completely new to the concept of belt drives and, when doing some initial research, the Wikipedia article on belt-driven bikes says that they have the disadvantage of
Problems in snowy conditions (up to complete inoperability in some cases).
Has anyone had any experience with snowy commutes on a belt-driven bike supporting or refuting this claim?
The belt drive on my Srida gathers lots of wet snow, making it completely useless throughout the entire winter. In addition, if the temperature is around 0 degrees, the bicycle parts are prone to icing, which is the major problem for the belt drive too.
See also another customer review
Belt drives require some mechanism to prevent the belt slipping off of the sprockets sideways.
(doing a little research, number 3 is the "Gates Center Track" that just came out at Interbike 2011 and the bike I saw with it was probably one of the first production bikes of that model off the assembly line)
I have been riding a Gates CDC (not Centertrack) belt drive for almost a year now. I have ridden my bike in various weather conditions and temperatures ranging from over 90℉ to under 0℉. I have ridden through a variety of snowy conditions, including a foot-and-half of fresh snow on a few occasions, but more commonly mixed snow/ice/slush conditions. I have encountered two major problems in winter conditions so far.
The first problem is changing tension. I use the Gates iPhone app to check my belt's tension. I have noticed that, if the belt is tensioned properly at about room temperature, then the tension in the belt decreases below the recommended tension range when the ambient temperature drops below about 20℉. I have noticed problems with the belt drive when tension is too high or too low, including excessive noise, skipping, and misalignment leading to dropping the belt from the sprockets. Therefore, I found it necessary to retension the belt slightly in the beginning of the winter and again at the end of winter. I'm not certain yet if the weather-related change in tension is caused by frame shrinkage (I suspect this is the case - my frame is aluminium) or by another factor.
The second problem is getting snow in the drivetrain. Under certain winter weather conditions, the belt will drop from the sprockets. I've had this happen on several occasions, and it's quite annoying, as there's not much you can do when you're on the road besides remount the belt and pray it doesn't happen again on your ride (spoiler alert: if the belt drops once, the belt will get dropped again). However, this does seem to require the perfect storm of conditions: you need the belt tension to be low (possibly because the temperature is low - see above), and you need very heavy, wet snow that sticks to the components of the drivetrain. When the snow and cruft starts building up on the sprockets and belt, the liklihood of dropping the belt increases dramatically. The solution to this problem seems to be to increase the tension of the belt, though I found it necessary to take care not to increase the tension too dramatically, as an overtensioned belt can be very noisy and create a lot of resistance in the drivetrain.
Overall, with winter weather in the mix, I've found that the belt is not the universal, maintenance-free drivetrain that Gates claims it to be, though with a little care, it does require less frequent attention than a chain-based drivetrain.
In addition to @jeyhendren and @phil-johnstone nice answers I want to add my 3 findings.
First year with snow I (RieseMüller/Bosch/Nuvinci/center track) had no problem whatsowever. I can't remember the quality of the snow but during a winter it must have been sticky several times.
Then 2 weeks ago the belt jumped and, contrary to instructions, I tried to put it on again, like we do with chains. It broke. There was a lot of snow in(?) and around the drive train.
Yesterday my new belt jumped and there was lots of snow everywhere. (Skiddy and snowy and really fun.) The belt was stuck between wheel and frame and I had to bend it slightly to get it loose. This time I did not try to put the belt on again but walked the bike home and fixed it at home. Today the belt broke in an up hill. There was no snow on the belt and hardly any on the drive train.
My present guess is that the belt gets a damage when it jumps and loses its strength.
Two weeks ago I would have answered the question "snow - no problem!". Today I am not as sure.
Update
I am back to believe snow is not the culprit. My problem was a loose rear sprocket. The rear sprocket seems to have a really nice construction for not catching debris. A twig or an unfortunate piece of ice would make the belt jump though.
I've never ridden one but the Carbon Drive Systems website states that:
The patented sprokets contain Mud ports that shed even the worst type of debris. Not even snow or mud will slow you down.
In theory, since the sprockets are so wide, and the belt lacks holes, snow/mud that gets between sprocket and belt will be packed into the notches and could build up if conditions are right. This could build up to where it locks the belt (or damages it, if the rider tries to force the thing), in the worst case. In any case, it's not going to make pedaling any easier.
I was just reading where truck off-roaders have a lot of trouble with mud in their serpentine belts, in some cases damaging the belt or the bearings of the generator or idler.
No experience with bicycle belt drive, though, in any conditions.
Added:
I do notice, in the belt tension thread, that the front sprocket has large holes in it and, one would expect, would not have much trouble with snow/mud buildup. The rear sprocket (in the image presented) is not seen well enough to say if it has holes in it, but it looks like not -- at least not as big as the front. Other bikes may be different, of course.
