Wow, that manual for Rohloff hubs has lots more useful information than we received with our Gates system. And I'm not sure the news is good. There's a big $ difference between replacing the belt ($85) and replacing the sprocket and belt ($450) every x (still to be determined) miles. Once we did the field repair on the eccentric we completed the remainder of the 200km and had no additional problems (other than the usual vexing experience with the Garmin rerouting our brevet for a shorter distance - and a disqualification).

We were planning on testing the new replacement belt anyway. As a randonneur, we like to test our replacement parts in advance of needing to use them. We haven't yet been tested on our backup strategy and ingenuity on 600km rides when a critical component fails 200 miles from our start but it will happen someday in our cycling life. We usually joke about paying a towing service (available even in the smallest rural area) to haul our sorry selves (and tandem) back to the start.

We'll contact Gates this week and order the gauge to test the belt and sprockets, which I didn't know existed. Thanks for the link! We'll also try to determine our exact miles but we know we had >6,000 in 2010 plus a lot of miles in 2009. Again, we've been very happy with the Gates and specifically spec'd one for a second tandem we bought late last year. We are riding long to train for Paris-Brest-Paris this year and are a high mileage team.

We hope to hear from some other Gates owners who have faced the replacement issue. Did you replace just the belt ... or the entire system???