changing to compact chain rings on sram

ed muggles
Posts: 27
Joined: Mon May 23, 2011 5:59 pm

changing to compact chain rings on sram

Postby ed muggles » Thu Feb 07, 2013 8:25 pm

i was looking at getting some compact chain rings for the road bike (BMC RM01)that is running sram red.
my question goes some thing like this,
do i need to get a compact crank or can i just get some compact chain rings?

cheers

Ed

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find_bruce
Posts: 5962
Joined: Mon May 09, 2011 8:42 pm
Location: Sydney

Re: changing to compact chain rings on sram

Postby find_bruce » Thu Feb 07, 2013 8:40 pm

Standard cranks 53/39 usually have a 130 bcd (bolt centre diameter) while compact cranks 50/34 have a 110 bcd.

I believe this applies to SRAM red as well.

Long & short you need compact cranks
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ed muggles
Posts: 27
Joined: Mon May 23, 2011 5:59 pm

Re: changing to compact chain rings on sram

Postby ed muggles » Thu Feb 07, 2013 8:43 pm

cheers thanks for that

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Riggsbie
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Location: Geelong, Vic

Re: changing to compact chain rings on sram

Postby Riggsbie » Thu Feb 07, 2013 8:57 pm

My SRAM Rival compact crank has 130bcd....

Swap it for your SRAM Red crank......I want to go the other way from 50 to 53....


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ironhanglider
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Location: Middle East, Melbourne

Re: changing to compact chain rings on sram

Postby ironhanglider » Thu Feb 07, 2013 11:48 pm

Riggsbie wrote:My SRAM Rival compact crank has 130bcd....

Swap it for your SRAM Red crank......I want to go the other way from 50 to 53....


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Presumably this is a mistype. You can't have a compact with a 130bcd spider, the smallest ring possible is a 38T which is not usually considered compact.

Cheers,

Cameron
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