Sram Etap crankset compatibility

knigsc · November 2016

Hello All,

So I'm looking to build my first bike and have acquired a cervelo frame that I’m looking to build it up myself over the winter.

It’s going to be my “Sunday best” bike so have opted for SRAM red etap throughout but I'm unsure what crankset to get.

In a perfect world I would like to fit SRAM red cranks to match the rest of the groupset but this would require the use of a GXP adapter and that’s a route I don’t want to go down currently. So, it appears that’s there are limited options (3) if I want to take full advantage of the native Bbright system:

Rotor 3D+
FSA K-force Light
SRAM force22

I was going to opt for 3D+ as rotor are synonymous with cervelo but reading through various reviews/forums, it seems there could be some etap compatibility issues (crank arm clearance seems to be the main issue as well unsmooth gear changes etc).

Similarly, I’ve read the FSA chain-rings don’t play nicely with etap either. SRAM Force, I assume would have the best compatibility out of the three but it’s a heavy set.

I want the best setup, regardless of cost (within reason!). I don’t see the point of running a group set like etap and having a noisy drive chain and wince inducing crunches when changing gear, not to mention complete failure to shift or dropped chains.

I did think I could I install red 22 x-glide chainrings on the one of these cranksets, but I assume there will be compatibility issues with between some crank/chainring combinations ??

I welcome your comments/thoughts/suggestions.

sungod · November 2016

i've used old 10-speed red and modern praxis works chainrings with etap, the latter were a bit smoother shifting, in both cases these were on my old srm/sram powermeter

it's a bit fiddlier to adjust the etap fd with non-yaw rings, but once done correctly the shifting is fine

you can get x-glide chainrings in two versions, hidden bolt, non-hidden bolt, for a 'normal' spider you need the non-hidden type, as long as you fit the correct rings for the spider they should be fine

crank arm clearance will also depend on the frame geometry/size, the fd lower limit screw may stick out too far for some, but that's easy to resolve

there's a long thread on ww that gives plenty of examples...
http://weightweenies.starbike.com/forum ... &start=675

apriliarider · November 2016

Try these guys before you dismiss the GXP option - I had problems getting a gxp bb to fit my Cipo with etap - emailed them with any questions and sorted the one I needed - no adapters, ceramic bearings, £100 and delivered in 3 days !!

Quality is fantastic and ultra smooth :-)

https://www.c-bear.com/bbchart.pdf

Cheers

MW

hambini · November 2016

I certainly wouldn't recommend the rotor cranks. I've got an S5 and every time I came up to a hill to change from the big to the smaller chain ring I was hoping the shift went smoothly as sometimes the chain would drop off or fail to change etc. I really don't rate the rotor cranks at all.

StillGoing · November 2016

hambini wrote:

I certainly wouldn't recommend the rotor cranks. I've got an S5 and every time I came up to a hill to change from the big to the smaller chain ring I was hoping the shift went smoothly as sometimes the chain would drop off or fail to change etc. I really don't rate the rotor cranks at all.

Is that with eTap? I have Rotor 3D24 with a SRAM non-eTap set up and have absolutely no problems even with Q rings fitted.

knigsc · November 2016

sungod wrote:

i've used old 10-speed red and modern praxis works chainrings with etap, the latter were a bit smoother shifting, in both cases these were on my old srm/sram powermeter

it's a bit fiddlier to adjust the etap fd with non-yaw rings, but once done correctly the shifting is fine

you can get x-glide chainrings in two versions, hidden bolt, non-hidden bolt, for a 'normal' spider you need the non-hidden type, as long as you fit the correct rings for the spider they should be fine

crank arm clearance will also depend on the frame geometry/size, the fd lower limit screw may stick out too far for some, but that's easy to resolve

there's a long thread on ww that gives plenty of examples...
http://weightweenies.starbike.com/forum ... &start=675

Thanks for the great info .. i can overcome the FD clearance problem easily by the sounds of it.

So I looked into force and I cannot find it for love nor money in a 52/36 despite the sram website stating they are available. Shame because this would be the easiest way forward for me personally.

I then started looking for sram red x-glide chainrings "non-hidden bolt" (rotor 3d+ spiders are all NHB I believe?) . My research has led me to believe the sram rings have the ability to move the pin between hidden and non hidden positions on the ring , effectively allowing to fit both spider types. Can anyone confirm this ?

Thx

sungod · November 2016

try fudges, they are usually good for sram, they may be able to order them if there's no stock

some x-glide pictures show a single pin in 'hidden' position, but there are also rings that have two pins, one in each position, for instance...

...you might need to file a bit off the chainring tab at the 'hidden' position to fit a different spider

apriliarider · November 2016

I had to source my 52/36 from Germany as LBS / online could not get any or say when they would be in stock

MW

StillGoing · November 2016

I bought an exogram 11 speed chainring set with hidden bolt set up. My SRAM Red crankset is non-hidden bolt. There is a small grommet you can tap out and then move the pin to hole. I'm sure SRAM designed it this way rather than having two separate designs for 10 and 11 speed.

knigsc · November 2016

Thanks all, some good advice here.

I spoke to fudges who weren't able to help this time around but i did indeed find the chainrings (52/36 110bcd) on bike24 and have ordered.

I have also opted for the force 22 crankset. I ended up buying a compact with 110bcd (absolute bargain i might add) and will swap the rings to the 52/36. If it all fits together as planned i should be able to recoup some money from the spare 50/34 rings on eBay.

Seems bit of a convoluted way of doing it i must admit but just nothing out there mid compact.

beanstalk · December 2016

Hello,
I have an issue with my Shimano FC-9000 50/34 crank set and the eTAP front derailleur.
The crank arm rubs on the derailleur at the adjustment screws and there is generally almost no clearance at all:

With an Ultegra FC-6600 53/39 crank set there is sufficient clearance:

Is there anything I can do to get the FC-9000 compact crank working with that derailleur?

sungod · December 2016

the fd is quite deep, with a wide seat tube and/or chainring/crank that is closer in, you may run out of space

from the images, you may have a combination of the two, the adjustment screws on the fc-6600 look like they're further out, suggesting there's a real difference in chainring offset

you could fit shorter screws, or grind a bit off the ends of the existing ones, but bear in mind that going small to big ring, the fd 'overshifts', then moves back slightly, i.e. even if there is clearance under static conditions, the crank can still clip the screw if it is passing the screws during the overshift period

not familiar with the cranks, is there any option to fit a shim/spacer on the axle to move them slightly further out?

gaffer_slow · December 2016

looking at upgrading to etap. anyone using a rotor 3d24? Wouldn't want to have clearance issue with the arm

beanstalk · December 2016

sungod wrote:

the fd is quite deep, with a wide seat tube and/or chainring/crank that is closer in, you may run out of space

from the images, you may have a combination of the two, the adjustment screws on the fc-6600 look like they're further out, suggesting there's a real difference in chainring offset...

I've put a cassette Spacer under the right BB shell, general clearance is OK now.
It is down to the adjustment screws now, I will cut them.

NeXXus · December 2016

beanstalk wrote:

sungod wrote:

the fd is quite deep, with a wide seat tube and/or chainring/crank that is closer in, you may run out of space

from the images, you may have a combination of the two, the adjustment screws on the fc-6600 look like they're further out, suggesting there's a real difference in chainring offset...

I've put a cassette Spacer under the right BB shell, general clearance is OK now.
It is down to the adjustment screws now, I will cut them.

Why not space the BB out more unless it's going to horrifically alter your chainline?

Zachlaw2 · April 2017

beanstalk wrote:

sungod wrote:

the fd is quite deep, with a wide seat tube and/or chainring/crank that is closer in, you may run out of space

from the images, you may have a combination of the two, the adjustment screws on the fc-6600 look like they're further out, suggesting there's a real difference in chainring offset...

I've put a cassette Spacer under the right BB shell, general clearance is OK now.
It is down to the adjustment screws now, I will cut them.

Hi I'm about to build an ETAP with a rotor crank where i have read similar issues may occur. Did you manage to grind the screw down? If so any pointers on how you did it? Simply a file??

Thanks

sungod · April 2017

the screws are titanium, i used a dremel with an abrasive bit

from memory i took off about 1.5mm

Zachlaw2 · April 2017

sungod wrote:

the screws are titanium, i used a dremel with an abrasive bit

from memory i took off about 1.5mm

Thanks, was this on the bottom side where the screw hits the limiter, or on the top where the hex key went?

sungod · April 2017

grind material off the tip, not where the hex key goes

Sram Etap crankset compatibility

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