|Ultegra/XTR ?||HENRY K|
Nov 12, 2003 8:30 AM
|Can I mix my Ultegra rear (12-27) with an XT or XTR crank and chainring on the front of my Cyclocross bike? I assume that I also must use a matching XT or XTR front deraileur as well. If not...are there any suggestions on what to use without switching the Ultegra rear gear?|
Nov 12, 2003 10:43 AM
|Yeah, you could do that, however it will require some modification. If you have a standard road double crank on there right now you will need to get a new b.b. suitable for a triple crank - typically 113mm. Using a mountain front derailluer will only work if you are using mountain shifters. Shimano road shifters have a different aspect ratio (cable pull vs. derailluer movement) for the front derailluer. If you are using barcons, then you will not have any difficulties, as they are friction only for the front.
What you could do to avoid this hassle, would be to get some more cross friendly gears for your road crank. A lot of guys will run a 48/38 ring setup in front - that should help to reduce your gearing. Weigh your options, changing the cassette would probably be cheaper than changing the chainrings.
Nov 13, 2003 5:44 PM
|Perhaps I did not give enough information. I would like to use bar end shifters. I would also like to stay with the 12-27 in the rear so I can switch wheels with my road bike if I want/need to. I have a triple on the bike now and I would like to keep a triple with the mountain crank. Does that change any of the answers?|
|road shifters have different aspect ratio????||cyclopathic|
Nov 14, 2003 10:24 AM
|only '96 and pre DA had diff ratio /in rear/ it had not been an issue since. Tandems usually set up with XT/XTR front der and STI shifters, works fine.|
|Ask on the CX board. They have tried everything...twice. (nm)||TFerguson|
Nov 12, 2003 4:16 PM
|The answer is...||MShaw|
Nov 13, 2003 12:46 PM
|Yes. You can run the XTR crankset.
Yes. You will probably need a mtn front derailleur. I'd stick with XTR since its designed for the slightly bigger gears.
Yes. It will shift with your Ultegra STI. Mine does.
Yes. Anything up to about 29/30t in the back is OK with the Ultegra rear der. as long as you're not running a triple. The Ultegra doesn't wrap enough chain for a triple in front. I know 'cause I tried it on my first cross frame and ended up with my derailleur wrapped around my dropout. Oops! That was a looooong walk home.
You may have to fiddle with things a little to get them just right. Once you do, there shouldn't be any more problems.