1x 10 or 11 Front Chainring

[WolfTooth]

Hi all,
I am sure there are other threads on this, but I wanted to take a quick poll on front chainring sizes for CX when running a 1x10 or 11.

Please comment back and list different sizes if you would use a "nice conditions size" and "muddy size".

Thanks!

Wolf Tooth

https://www.facebook.com/pages/Wolf-Too ... ef=tn_tnmn

[Devon]

I'd personally use something in the low-mid 40s. It does however depend a fair bit on the ratio of the cassette you are using.

[the_marsbar]

Personally I would probably have a hard time without a 39T ring in some races. In other races I'd be fine with a 42T single ring I think. Maybe 38T, 40T, 42T?

[limba]

I think SRAM should make XX1 for cross (and then Wolf can make chainrings for the crank). Get rid of the front derailleur completely. Get a big ring 42/44/46/48 and a big ass cassette and you're done. They wouldn't have to worry about competing with Di2's superior front shifting. Makes sense to me...

[nigel379]

Please, please, please make a 42t 130mm bolt pattern xx1 chainring for those of us running single rings. I want to ditch my chain catchers.

[gt5504b]

I opt for a 38 or 40 on most courses with an 11-25, or a 42 with a 12-29.
I've even used a 36 in a couple of muddy races, but I'm not exceptionally fast and even I spun out on that.

[LittleSprinter]

I just took off the 53 chainring and using some spacers, I raced cross with a 39 front and 11-23 cassette. It worked great for hilly/ muddy races and flat dry races.

[grover]

42 got me through every race last year with 11-25.

[winky]

Or you could just go with a 1x11 setup using...
- CX frame with 135mm rear spacing
- SRAM XX1 rear hub
- SRAM XX1 cassette
- Dura-Ace 11 speed rear derailler

[HillRPete]

winky, I'm fairly sure that the DA RD will have a hard time coping with the XX1 cassette. It's just not built for such big cogs. Wondering if the cog spacing is compatible too.

[winky]

winky, I'm fairly sure that the DA RD will have a hard time coping with the XX1 cassette. It's just not built for such big cogs. Wondering if the cog spacing is compatible too.

If I am not mistaken, you can replace the derailler pully cage on a Dura-Ace cage to something longer so that you can use larger tooth cassettes.

[HillRPete]

The DA 9000 RD has a total capacity of 33t. To run an XX1 cassette you need 42 - 10 = 32t. The problem is not taking up the slack chain ("capacity"), but clearing the big cogs. As per spec the 9000 RD can do 28t max. I've seen tweaks to handle 34t max (10t top cog, max out "B" screw), but clearing 42t will be nigh on impossible.

Happy to be proven wrong though.

[winky]

The DA 9000 RD has a total capacity of 33t. To run an XX1 cassette you need 42 - 10 = 32t. The problem is not taking up the slack chain ("capacity"), but clearing the big cogs. As per spec the 9000 RD can do 28t max. I've seen tweaks to handle 34t max (10t top cog, max out "B" screw), but clearing 42t will be nigh on impossible.

Happy to be proven wrong though.

The Dura-Ace rear derailler is only spec'ed to handle a max rear cog of 28T like you said. So, just remove the DA pulley cage and put on a MTN bike derailler pulley cage. I would go on Ebay and find a good used XTR derailler, then use the derailler cage from that on your DA11 rear derailler and SRAM cassette.

[HillRPete]

Cage size doesn't influence max cassette size restriction, because it only moves the bottom pulley, not the top one. Problem is that the top one moves into the cassette, if it doesn't clear the cog size.

[ms6073]

Please, please, please make a 42t 130mm bolt pattern xx1 chainring for those of us running single rings.

That might be a bit of a problem seeing as XX1 based on a spider with a 76mm BCD.