# Compact Cranks that will support 52/36 chainrings?



## sgalante (May 5, 2009)

Felt offers a one of their bikes the F3 F3 Road Bike - Felt Bicycles with the SRAM S950 crankset that has a 110mm BCD using both 52 and 36 tooth Red chainrings. Does anyone know if I can use those same RED chainrings on any of the other SRAM compact cranksets, given they also use a 110mm BCD? I went to the SRAM website, and don't even see the S950 crankset, but I did talk to someone from Felt, and they verified the specs on the website. 

I am looking at both SRAM Rival and Force equipped bikes with 50/34 chainrings on them, but really like the idea of having the extra 2 teeth on the big ring and feel I can handle the 2 fewer teeth on the small ring. I'm not sure if the only thing I have to take into account is the BCD or if something else comes into the picture. Unfortunately, I can only order either bike with the 50/34 chainrings.

Thank you in advance for your help.


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## robdamanii (Feb 13, 2006)

As long as it's 110 BCD, it should be fine.


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## divest (Feb 8, 2010)

I have that chain ring set up on some 110 BCD Rival cranks and really enjoy it


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## sgalante (May 5, 2009)

Thank you both for your quick replies.


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## deviousalex (Aug 18, 2010)

Is a 52/34 setup possible or is 18 teeth just too big of a jump for the derailleur to handle?


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## Winters (Dec 4, 2011)

Shimano fd 105 says 16 teeth max .... FWTW.
.


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## cxwrench (Nov 9, 2004)

deviousalex said:


> Is a 52/34 setup possible or is 18 teeth just too big of a jump for the derailleur to handle?


i'll bet that wouldn't work too well...


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## Camilo (Jun 23, 2007)

deviousalex said:


> Is a 52/34 setup possible or is 18 teeth just too big of a jump for the derailleur to handle?





cxwrench said:


> i'll bet that wouldn't work too well...


Frankly, my opinion (based on a lot of experience with conventional double and triple cranks with ~12 tooth jumps, but only one 50-34) is that 16 tooth jumps = pretty crappy shifting, 18 would be horrible.


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## sgalante (May 5, 2009)

Camilo said:


> Frankly, my opinion (based on a lot of experience with conventional double and triple cranks with ~12 tooth jumps, but only one 50-34) is that 16 tooth jumps = pretty crappy shifting, 18 would be horrible.


I have had pretty good luck with shifting on 50/34 Compact Cranks using the proper FD, so I don't see where the 52/36 shifting should be any different. Since, when I get around to ordering my new bike, I will always have the 50/34 to fall back on, and even have a somewhat standard Compact 50/36 set-up, I think I will have the best of both worlds. I happen to be someone who has a somewhat slower cadence, and like the idea of having a 52/11 to crunch when I want to.


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## deviousalex (Aug 18, 2010)

Well, the crank diameter doesn't grow linearly with tooth count, so 52/36 might be a worse shift.


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## sgalante (May 5, 2009)

deviousalex said:


> Well, the crank diameter doesn't grow linearly with tooth count, so 52/36 might be a worse shift.


Can you explain what you mean by that? My calculations tell me that the proportion of the size of the chainrings should almost be identical, within about 1% or so.
I'll see if I can find exact measurements on the Sheldon Brown website.


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## deviousalex (Aug 18, 2010)

Ooops, your'e right! I was thinking area.


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## NEO Dan (Jun 10, 2010)

Out of curiosity what cassette 11-? and what category are the climbs?


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## sgalante (May 5, 2009)

Dan, 

If the question was directed at me, I will probably start out with the 11-28 and probably move to either the 11-26 or 11-25 at some point down the line, when my legs are a little stronger. I don't have too many climbs in my area. I have do have a short steep climb that I can just barely accomplish when I am in my best shape that I can do in my 39/26 on my current bike, but I would like to be at a cadence a little faster than about 25-30 when I get to the top.


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