Apologies - another compatibility question

[tbar23]

I've searched around and can't seem to find an answer to this question. I have a road bike built with a Sram Red 22 groupset. Compact crank double front chainring and an 11-speed cassette. PF30 bottom bracket.
I would like to convert this bike to a hill climber with as little modification (read "purchases") as possible.
I think my ideal setup would be something like a Sram MTB crankset (e.g. XX in a 39-26t) along with my existing rear setup.
Will this work?

Another possibility is to use a 1x crankset ... I think there are some 26 or 28T cranks available. The one downside to this approach is that the hill climb I have in mind has about a 0.25 mile of flat at the beginning, and it would be nice to have the larger chainring for that part.

Thoughts?

Going with a 32T or even 36T cassette in the rear won't cut it. I'd like to get comfortably under 1:1 for my lowest gear.

Thanks!

[ripvanrando]

To get well under 1:1

Get a mid cage SRAM derailleur

11-32 Cassette

39-26T crank

The question to me is whether your FD is a clamp or braze on mount. If braze one mount, will it allow a low enough position to shift a 39-26T set of rings? If clamp, I see no problem. I had thought of a similar setup (42-30) but did not execute it.

[tbar23]

I have a mid cage RD and a suitable cassette. I wasn't sure if the geometry of a BB30 MTB crank is compatible with the road geometry (width, offset, etc)

I do have a braze-on FD so that's a consideration.

[David Tollefson]

You'd want to go with something like the Sugino OX series (compact plus mini goes down to 28T on the small chainring), or one of the offerings from Stronglight.

[ripvanrando]

I have a mid cage RD and a suitable cassette. I wasn't sure if the geometry of a BB30 MTB crank is compatible with the road geometry (width, offset, etc)

I do have a braze-on FD so that's a consideration.

Depends on the selected crank and your BB shell. Chainline is the question that I had researched. I seem to recall there was one that would have worked but the FD shifting with a road SRAM Yaw was something that I could not find an answer on. I see plenty of Mtb doubles on road bikes but not with SRAM 22 but then again SRAM 22 is not all the popular especially set up with gearing for real humans in hilly terrain. Sorry not better help.

[tbar23]

Thanks, all. So it sounds as if I pretty much have to just take a shot at this and see how it works. I'll report back, if successful (or not ;)

[cp43]

Maybe something from here?

http://www.wolftoothcomponents.com/collections/cassette-cogs

I don't know if they have something for SRAM 11 or not. But the idea would be to keep your current cranks, and go for a bigger (40 or 42 tooth) big cog on your cassette.

Another crank option: http://www.whiteind.com/road-crank

Chris

[ripvanrando]

I had thought it would work using my existing SRAM Red 22 front derailleur but as indicated, I did not go that route. The FD does seem to have a lot of adjustability and I also understand the mountain and road FD are compatible and I had thought that worse case, I'd need a new FD. I was dealing with a BB30 bottom bracket. I think it was either SRAM or Shimano that had a double with a narrow spindel that I thought would work. Most are wide (big Q factor)

Please post back on your success.

[ColonelJLloyd]

You could certainly replace your crank with an XX and get the gearing you want. You'll want to also replace your FD (preferably with an XX model).

I'm running the following with great results.

Rival 22 shifters
XX 42/28 156Q crank (GXP) 68mm shell, 135mm rear spacing, disc
XX bottom pull FD
Rival 22 WiFli RD
11-32 11s cassette

The reason I went with with the XX crank was the combo of Q factor, 42/28 rings and stiffness. I've been very pleased.

[tbar23]

@cp43 - do any RDs exist that can handle a 50/34 crankset with a 10-42T cassette? That's a 48T capacity.
As it is a hillclimber, I'm also concerned about weight - so a pie platter rear cassette with a very long cage RD might take me the wrong way. Of course, the Sram Red crankset is ludicrously light, so changing that out will almost certainly entail a weight penalty.
I think the White Industries stuff might be square taper BB only??
Just heard from them, though - sounds as if some BB30 stuff is coming.

David - I don't see the Sugino OX combo you mention on their website. Am I just missing it?

@ColonelJLloyd - clamp-on or braze-on FD? Any issues getting it low enough?

Thanks for the input!

[cp43]

You probably won't be able to find a RD that is spec'd to take a 48t difference. My experience is that you can easily go beyond the spec though. Not massively beyond, but running a 48 tooth difference with a RD spec'd for 42t should work fine. Mostly, I was checking to see if you had explored the bigger cassette option, as that's (usually) easier and cheaper than the smaller cranks option.

I did find this: http://www.aebike.com/SRAM-GX-2x11-Speed-Long-Cage-Rear-Derailleur-Red_p_82981.html

It's spec'd to 46 teeth of wrap, IMHO, that's close enough to 48. I don't know if it would be compatible with your shifters though.

You are correct, the WI cranks are, as far as I know, square taper only.

Good luck with the build!

Chris

@cp43 - do any RDs exist that can handle a 50/34 crankset with a 10-42T cassette? That's a 48T capacity.
As it is a hillclimber, I'm also concerned about weight - so a pie platter rear cassette with a very long cage RD might take me the wrong way. Of course, the Sram Red crankset is ludicrously light, so changing that out will almost certainly entail a weight penalty.
I think the White Industries stuff might be square taper BB only??
Just heard from them, though - sounds as if some BB30 stuff is coming.

David - I don't see the Sugino OX combo you mention on their website. Am I just missing it?

@ColonelJLloyd - clamp-on or braze-on FD? Any issues getting it low enough?

Thanks for the input!

[ColonelJLloyd]

@ColonelJLloyd - clamp-on or braze-on FD? Any issues getting it low enough?

I'm using a clamp on XX FD. The reason I got it is because I was trying to use a Rival 22 FD and the cage would hit the DS chain stay before it got close enough to the 42t chainring. I can say that the combo of Rival 22 shifter, XX FD and XX crank are giving me the best front shifting I've ever experienced.

I don't know if it would be compatible with your shifters though.



GX is X-Actuation, so it would work with "road" shifters.

[David Tollefson]

Sugino Ox801D and Ox601D. The 801 can get down to a 40/26 on the Soma site. (not cheap, however)