I have the Mountech drivetrain on my 85 Schwinn Le Tour Luxe which is a touring bike. I bought the bike last winter with only 250 miles on it so the drivetrain is virtually new. It shifts the larger gear spread with quickness and ease, I like it...but it doesn't have much mileage on it either, and according to some sources the Mountech had problems. But those same sources said the Superbe Tech had problems yet I have a bike with that derailleur that has over 150,000 miles on it and never had a problem, how many miles can one expect?! So will the Mountech be the same sort of thing? I may never find out since I doubt that bike will see that many miles but it will be used for touring so maybe? Dirt as one mentioned being a problem? I've ridden it about 500 miles since I got it and so far no problems, but I clean my stuff regularly too.

Here's a web site with more info about that and a slew of other derailleurs: http://www.disraeligears.co.uk/Site/...284900%29.html
This is the same site that said the Tech was junk.