156mm is what sram quotes for their mountain double cranks.

This SRAM Doc ( http://www.sram.com/sites/default/files ... _rev_b.pdf" onclick="window.open(this.href);return false; ) states 145mm for the q factor which fits with the measured 146mm.

@thisisatest - not all XX cranks are 156mm. There are 3 versions, 156mm, 164mm and 166mm...

Yea- i was going to mention that, decided to not confuse the issue. Never heard of the 166 model though- was it made for one particular company's chubby bike with some junk in the trunk?

Is your crank 50/34 compact version? I've seen 53/39 standart on scale as 607g...

_________________
2012 Cannondale SuperX
2013 Cannondale Supersix Evo

@thisisatest - I saw the measurements on the SRAM website a while ago. Memory is a bit hazy but have a feeling the 164/166 difference was GXP vs. BB30/PF30 or something like that

I run a 166 GXP on my mtb. They barely cleared on my old bike (08 Stumpjumper FSR) but there is plenty of clearance on my 2011 Stumpjumper FSR. My friend was rubbing his 156q arms on my SC Blur LTC

Mine is a compact GXP version. The BB30 compact should be even lighter (~520g. if I recall).

I could really feel the reduction in rotational weight (166g.) I love the new Red crank.

^ how does it shift with extralite rc2? And did you have to rotate the rings?

Just received some compact bb30 cranks for the GF's bike.
Interestingly, they are within 40grams of my Vumaquads and would likely be lighter than without the super heavy chainrings.

Sram Red 2012 172.5 50-34


VumaQuad 175 50-34

So the new Red is lighter then my Hollowgram SL cranks.
For 172.5 50/34 with Praxis rings I am at 543g

I am building a second bike and have been looking for another set of Hollowgrams and am having no luck. At this point I should probably try the new Red, my biggest issue being the increased Q-factor over Hollowgram.

By going with lighter rings on the Red you'll save an additional 50 g. This will put the Red at 472 g. which is very light. I have the GXP version of the new Red and I love it. I got it for less than $400 from a LBS.

And finally here is my compact gxp 172.5mm on scale.
92g savings over my 7900 duraace crankset

_________________
2012 Cannondale SuperX
2013 Cannondale Supersix Evo

Thanks Boralb - scale pic, nice

I wonder how much heavier for a standard 130BCD?



GJ

Can you please confirm which rings that is with please ?