Need a new derailleur

[73fj55]

I have a low end Trek with Shimano Acero parts. From what I have researched the Acero, when they were offered, were bottom of the line. Anyway, I was riding home tonight and while I was switching gears my derailleur came off, snapped freaking off.

I want to buy a better derailleur but I want to make sure that it will fit. Should most of the Shimano's fit? Also if I switch the rear should I switch the front as well?

Thanks

 

[Mr. Toad]

I have a low end Trek with Shimano Acero parts. From what I have researched the Acero, when they were offered, were bottom of the line. Anyway, I was riding home tonight and while I was switching gears my derailleur came off, snapped freaking off.

I want to buy a better derailleur but I want to make sure that it will fit. Should most of the Shimano's fit? Also if I switch the rear should I switch the front as well?

Thanks

Shimano's shifters have to match the derailleur. I don't know what mixes and matches with Acero.

Front and rear need not be replaced at the same time. However, the above applies to front derailleurs too and is often more critical than in the rear.

 

[beaufort-fj60]

you can customize, but it might be a little funky if you don't fiddle with your bike.

on one bike I have a antique xt thumb-shifter, xtr rear derailleur, and a bullseye freewheel hub..... you can fine adjust the derailleur on the fly with the thumb-shifter.

 

[Lugboot]

I'm betting you have Acera components.

http://techdocs.shimano.com/media/t...RD/EV-RD-M340-2060A_v1_m56577569830609140.pdf

How many gears on the back end? 8?

As long as it's not Rapid Rise, and I doubt the Acera stuff is, you can put on most 8-9 speed rear derailleurs. Shimano Alivio, Deore, SLX, etc.

 

[Chef J]

IMHO, spend a little extra and just get an Xt build kit from somewhere like Pricepoint, everything will work together and you know your getting well engineered stuff

 

[cruiser7773]

matching the rear with the front is of zero importance; what you have to be concerned about is matching the derailleur with the shifter (read 'cable travel for indexed shifting') and the cog set (read ' spacing between cogs'). Cog spacing across the lines of any manufacturer is standard so long as you stay with the same number of gears. The only differences in the higher ends are the materials used and special milling that aids in speedier shifting. With Shimano, you also have to choose between standard and rapid-rise (read 'reverse-sprung). You must match the shifter and derailleur in this regard.