Bicycle Mechanics - front derailleur rubbing on high and low gears

Hi-

I've just gotten a 2004 Trek 1500. It has a Tiagra front derailleur on 3 chainrings and Ultegra on 9 gears in the back. Pretty exciting stuff compared to my previous bike (early 80's friction shifting). I have the limit screws and tension set on both, they shift nicely through the whole range of rings and gears. The only thing that isn't perfect is that the chain rubs the front derailleur.

It rubs when I'm on the biggest chainring and biggest gear, and when I'm on the smallest chainring/smallest gear. Those I could live with, but it also rubs when I'm on middle chainring/largest gear AND middle chainring/smallest gear. What the heck? Have other people seen this? Do people have Tiagra in the front and 9 gears in the back without this problem?

In general you shouldn't be running smallest chain ring/smallest gear or biggest chain ring/biggest gear. There's a good bit of overlap in the gear ratios involved. In general I will ride the largest chain ring in the top 5 gears, the smallest chain ring in the lower gears, and the center chain ring is more versatile, where I can generally use all the gears. You are dealing with a fair amount of angle when going between an outside chain ring and inside gear, or the other way around. I try to anticipate how low of a gear range I need when climbing, and downshift to the appropriate chain ring in a higher gear before I start the climb.

yeah I never use the big/big or small/small combos, but I'd like to be able to use both middle/small and middle/big...

I have a friction front derailleur. I never use those combinations. I have a 7 speed and only use the 4 smallest gears with the big chanring and three largest gears with the small chainring. The midlle chainring sees a bit more travel but I never use it with the smallest/largest gears and very rarely with the second smallest/largest gears.

If your LBS does free adjustments or a free tune up after a certain period of time, ask them to take a look at it and see if they can do anything. Chances are you're just going to have to live with that limitation but I have a Specialized with similar gearing setup, so my knowlege isn't specific.

Hi-

..... but it also rubs when I'm on middle chainring/largest gear AND middle chainring/smallest gear. What the heck? Have other people seen this? Do people have Tiagra in the front and 9 gears in the back without this problem?Tried using the trim functionin the front shifter?

trim. holy smokes. this sure is a step up from friction shifting.