Belt Tensioning
One of the most exciting and unique parts of the Trek District besides it’s amazing good looks is the fact that it features the Gates Belt Drive. There have been quite a few people, including myself, wondering just how you go about getting the tension and tracking set right and how it’s affected by having to take a wheel off. I had a chance to ask Trek some questions, and here is what I found out.
TD: I think the biggest question that people have is just how the belt tensioning and alignment work. I know that belt drives require a fair amount of tension to avoid slipping, and the alignment is pretty critical. Is it something that is easily done, does pulling the wheel off to fix a flat totally screw up the alignment?
TREK: The belt is tensioned at the rear dropouts, which attach to the frame via two bolts and slide horizontally. The drop outs are each one piece, but when the wheel is taken off and the drop outs are completely removed, the belt can be removed and replaced via a slit between the chain stay and seat stay on the drive side. There isn’t any lateral adjustment because the chain line is set by the BB spindle length and it’s nearly impossible to successfully have the wheel installed with the dropouts bolted in different positions, and since the drop outs themselves are not horizontal, the wheel is easy to install correctly. It’s not a quick release system, but installing and removing the wheel takes very little effort.
TD: As far as tensioning the belt, I was half expecting some sort of set screw like some of the horizon drop out bikes have. Without set screws, how do you have fine adjustment over the belt tracking and tension. It seems like it’s not a very refined method? Or am I just making it sound harder than it really is.
TREK: Since you’re actually moving the dropouts themselves, and not the wheel in the drop out, it’s much easier to set tension and position. I would say the sliding drop out system is easier to set than setting a wheel into the correct position of a traditional horizontal or semi-horizontal drop out. It is essentially impossible to set the wheel into the frame without the correct lateral spacing between the stays. All one has to do is pull back on the wheel till the belt is tight while the drop out retaining bolts are loose, tighten the bolts, then ride.
Tags: Belt Drive, Gates, Single Speed, Tension
This entry was posted on Tuesday, October 28th, 2008 at 4:12 pm and is filed under Trek District. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.
March 4th, 2009 at 2:34 am
Something to do with the tension and Belt drive.
One thing that has just occurred to me. From time a belt well wear and the obvious will happen, it will snap/break/fail.
Will it be easy change or will you be riding around with something else to provide the drive,
March 4th, 2009 at 5:20 pm
I don’t think belt breakage will be an issue.
I was able to acquire a Schwinn cruiser belt-drive back in ’99 (this model was not distributed to the public for some strange reason) and I have ridden the bike about 1500 miles over the last ten years.
The kevlar-reinforced belt has performed flawlessly – no slippage, no maintenance, no rust, no kinks, no stretching (have not ever adjusted the belt tension), the belt has not ever popped off the sprockets (pulleys?), and the belt has not broken.
The Trek uses a carbon-fiber reinforced belt, and carbon fiber is even tougher than kevlar, so I really don’t think you have to worry about the belt failing.
July 10th, 2009 at 6:58 pm
I have actually seen and ridden one of these guys and there actually does appear to be an adjustment screw like the one you asked the Trek rep about. I don’t see it in the pics up at trek, but it is pretty small, so it might be there. Or perhaps they have headed your suggestion
. I’ll be able to add more when I get mine next week. Has anyone else seen what I’m talking about?
July 30th, 2009 at 5:22 am
How difficult is it to get the rear wheel off? I am looking at getting a Soho which has a similar setup, but had heard it is a pain to get the rear wheel off for fixing a flat.
July 30th, 2009 at 6:29 am
I’ve changed a flat on my District already and it was very easy. You don’t even need to bother with the belt tensioning at all. It’s just as easy as any other (non quick release) wheel.