CX Build - SRAM XX Rear Derailleur Med?

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Permalink Reply by Chris Mayhew on September 6, 2011 at 6:32am

Do they have the same cable pull? Worth checking on that. Why not use a Red? Or a Force, that's a lot of $$ to spend on something that may end up being ripped off before the end of the season.

 

Also, is that the Powerdome cassette? They don't clear mud very well which is a draw back for 'cross.

 

For gearing go with a tight ratio up front, say 42/36. No bigger than 44 up front (even that is big). The inner will be determined by the BCD more than anything else. That is, if you get a standard crank the smallest you can run is 39. If you get a compact you'll run either 34 or 36.

 

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Permalink Reply by dclifford on September 6, 2011 at 6:55am

Thanks Chris.

 

I will look at the cable pull.......and yes, I guess I can look at the Red/Force. The XX looked like it might "fall" in my hands so I was looking for feedback.

 

As for the cassette, great question. I will ask the ebay seller as I can't tell from the posting. What options would you consider?

 

I appreciate you help. As much as I enjoy riding, I have a very limited understanding of components and how they work together. Any and all information is appreciated.

 

Cheers

 

FYI - I run SRAM Red on my Road Bike.

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Permalink Reply by Chris Mayhew on September 6, 2011 at 7:18am

That's cool if the XX falls into your hands. My main point was don't invest a lot of money in something that fragile so that still fullfills the spirit of what I meant. I'm not sure if XX has the same cable pull as Red or not. Groups seem to be becoming less compatible rather than more.

 

Just ask if the cassette is a Powerdome or not. Something like the 1090 works way better.

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Permalink Reply by David whitlock on September 6, 2011 at 8:00am

 

The XX is 10 speed compatible and will work with SRAM road shifters.

I've been running a Red 11/28 cassette on my CX bike for almost a year now (bought it really cheap) and it has been great.  A little noisy, but very light and I haven't had any problems with mud clearance.  I wouldn't go out of my way to buy one new and Chris is right, the 1070 is better for CX. 

** Be warned that the 1090 cassette doesn't fit on every free hub body and if it does, it may dig more deeply into the spines because it only has two contact points (it's hollow).  Wheel manufactures such as Easton have a separate free hub body for Red cassettes.

   

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Permalink Reply by David whitlock on September 6, 2011 at 7:15am

Yep, that's actually a nice setup.

Depending on how strong you are a 34/36 small a 46 large would give you a good range of gearing for your crank set and unless you have legs like tree trunks the 11/46 will probably not get much use. 

 

Also, you can run up to a 38 tooth cassette on the XX (36t in the literature, but who reads that stuff) so if you find yourself running out of gears you have other cassette options to choose from. 

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Permalink Reply by Ohio Farmer on September 6, 2011 at 7:28am

I agree with what Mayhew said. Go with a Ultegra  or Force on the back, run a 11/28 or 11/27 in the back.

Don't waste your money on that xx derail, unless you have it to waste. Better to spend that on another set of tires and or a nice tubular wheelset.

 

However, the smallest ring you can run up front with a standard crank (130bcd) is actually 38 teeth.

 

If you wanted to run a single 39 or even 40 tooth Thorne (cyclocrossworld.com) single ring, and an 11/27, you can pretty much ride just over 30 mph max. Which is plenty for a 1 x 10 and 98% of the cross races out there. Even on the USGP courses, you might not hit above 30 except the start and maybe a long finish.

Or if you like to spin a bit more I like Chris' idea of not running more than a 44 up front.

You can do say 38/42 or 38/44 on a standard crankset or

spend some dough and get a compact crank.

Also, watch and make sure your outside ring has ramp pins whatever you purchase.

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Permalink Reply by dclifford on September 6, 2011 at 11:52am

Thanks everyone for your input.

I will let you know what I end up doing.

 

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