road derailleurs on mtb

zachhandler

I'm building up a light xc mountain bike with an ultegra 12-27T cassette. I'm deciding between a long cage xtr derailleur (which I have around) or an ultegra triple rear derailleur.

Any advice on the pros and cons of each?

My concern with the long cage xtr is shifting speed. My concern with the ultegra is durability. i ride fast cross country trails, mostly dry, and don't do any big drops or anything.

Thanks,
Zach

daveornee

The total wrap amount on the Ultegra will be less, but unless you have a very large range of chain ring change, it should work and be durable enough. However, I would probably stay with the XTR as I don't think you will note any difference in shifting speed... unless it is worn and/or needs an overhaul.
I think durability is a toss up between the two.
I have used both, but I am staying with XTR Derailers on everything from tandems (road and MTB) to touring bicycles. They work well and shift very well. I would suggest Shimano chain if you want the best in shifting.
Your milage may vary.

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David Ornee, Western Springs, IL USA

scottiebaird

I would use a connex chain, rather than a shimano. the shimano are renound for breaking. just make sure you get the correct width.

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Stay upright, unless otherwise required.

allmountain

The only reason a chain will break is due to misinstallation. Never reuse a pin after you have pushed it out - always use a new connecting pin (for Shimano), and never push out the same pin.

NOW you will stop breaking chains AND get good shifting.

leverfingers

Road derailleurs work just fine. I have always had one on my mtb. They won't take above a 28 or 30T cog. 32 and 34, which are common now, will not work. But why buy someting else when you've got an XTR on hand?

moparchris

its amazing how many people use the same pin more than once, infact i ahve to say i did it once, ages ago didnt know then but i know now ive got an S-RAM chain with the detachable.. thing i cant think what its called im gonna call it a 'detachable thing-a-ma-bob' which is alot more convinient.

anyway about the deraleurs, i dont think youd notice much between them, might as well go with what youve got

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2006 Giant Trance 1
Giant TCR Euro