new red chainrings on old red crank?

Discuss light weight issues concerning road bikes & parts.
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chiltonp
Posts: 118
Joined: Fri May 01, 2009 8:48 pm

by chiltonp

Needing some new chainrings and there seem to be some deals on the newer SRAM Red rings, (what is the difference between hidden bolt and non-hidden)?

Also this article below states that it is not very easy to simply bolt the new rings on the old crank, but it seems some on this forum have done it.
http://velonews.competitor.com/2012/03/ ... ity_209270

Would the non-hidden bolt chainrings mount on without the difficulty mentioned in the Velonews piece?

Also i've never swapped chainrings, do I need to pull the crank, or can I just un-bolt the old rings?

Thanks for the help.

dmoneysworks
Posts: 313
Joined: Tue Aug 07, 2012 6:35 am
Location: Parakai, New Zealand

by dmoneysworks

I have mounted the non-HB on my quarq S975 without issue, so you'll be right.

It's way easier to remove crank. Have a go, worst you can do is break a chain ring bolt if you doing it by feel!!

by Weenie


sungod
Posts: 1462
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

the hidden bolt simply refers to the mounting position on the yaw cranks, on old cranks the bolt isn't hidden

it's not a good idea to put the new rings on old cranks:

i) the anti-jam pin will be in the wrong place, just a cosmetic issue as long as you never have an overshift, if you do then you could end up with the chain stuck hard between crank and ring, possibly damaging something

ii) you have to file down a mounting tab on the small ring to make it fit

with the pre-yaw cranks (no hidden bolt) you can easily swap rings without removing the crankset from the bike

chiltonp
Posts: 118
Joined: Fri May 01, 2009 8:48 pm

by chiltonp

So am I understanding properly that the non-hidden bolt rings will be compatible, or is there still an issue with the anti-jam pin? Am I better off with a set of the SRAM Red Black chainrings, or Praxis?

sungod
Posts: 1462
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

any pre-yaw rings will be fine, hidden-bolt is specific to the yaw version

red-black, red-yellow, or original red, all will be perfect on a pre-yaw crankset, the pin will be in the correct position behind the crank arm

aaric
Posts: 439
Joined: Thu Jun 09, 2011 4:10 pm

by aaric

The whole point of a non-hidden yaw chainring is to fit old cranks.

look at the picture at http://www.artscyclery.com/Sram_Red_Yaw ... 130BN.html

the anti jam pin sits opposite a mounting bolt, so you are fine.

Compare that to: http://www.artscyclery.com/descpage-SRCRY53130B.html, which has the anti jam pin lined up with the hidden mounting bolt.

sungod
Posts: 1462
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

ah, hadn't seen they did a non-hidden version of the yaw ones, that's handy to know

aaric
Posts: 439
Joined: Thu Jun 09, 2011 4:10 pm

by aaric

I suppose to answer the OP's other question, it depends on what you are trying to achieve.

The Yaw rings shift very well, but are heavy. The old red black rings IMO aren't that great. Praxis shifts almost as well as yaw, but doesn't weigh as much - there's a thread on the exogram cranks that shows the weight differences.

Also, it depends on the ratios, and whether you are going compact or not. 36/52 isn't available for yaw for instance. Compact (assuming a 16T jump between rings) is going to shift worse than standard (39/53), so you might see a bigger difference in overall shifting quality.

If you want the best front shifting, go with Yaw rings on a Yaw derailleur. If you are weight conscious, go with Praxis.

If you are on a budget, with a standard front, old red might be good enough.

by Weenie


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