changing to compact chain rings on sram

[ed muggles]

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

[find_bruce]

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

[ed muggles]

cheers thanks for that

[Riggsbie]

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]

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....


Sent from my iPad using Tapatalk HD

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