Hi all,

Ive recently had to use a GXP Quarq on my S5 as I had to return my BB30 Quarq back to the US for servicing.  I therefore used the Enduro adaptor which has given me nothing but problems. Main issues are the NDS crank arm coming loose when riding, subsequent overtightening causing inward migation of the BB cups, and excessive drag/preload. The final straw was the failure/breaking of the self extracting NDS crankarm bolt while riding, causing a near accident.

A few days ago I reinstalled the BB Cups using Loctite 609, and used some blue loctite thread locker on the NDS crank bolt so it didnt have to be excessivly tightened.  This lasted one 90km ride before the whole BB cup assembly became loose and very noisey the crank bolt stayed put however!). Thankfully my replacement BB30 Quarq will be here in the next few days and i can get rid of this whole adaptor/crank setup!. 

The main issue i have found is with the Quarq with S975 arms that not enough shaft comes through the BB for the NDS crank arm to bolt onto.  This is largely due to having to run a 2.5mm spacer on the drive side so the chainline is similar to the factory crank.  Without this spacer the chain goes over the top of the big ring when in 53/11, which is something to avoid when your full on the gas!!

Anyone had any luck with the abopve configuration? After my ongoing and frustgration experiences, i would strongly suggest avoinding running SRAM GXP cranks via the Enduro adaptor on an S5.

Cheers Harry

EDIT - when i take this contraption apart and remove it I will take some pics for all to see...

re the 2.5 mm spacer to adjust the chainline:

is it just there to insure proper shifting ?

i would think that you should be able to adjust this through the front derailleur

GT1:

re the 2.5 mm spacer to adjust the chainline:

is it just there to insure proper shifting ?

i would think that you should be able to adjust this through the front derailleur

nothing to do with shifting.... i have found if i dont run a 2 to 3mm spacer on the driveside, then the large chainring is too inward with respect to the 11/12 tooth gear.  This results in a too big an angle on the chainline when in 53/11, so you run the risk of the chain coming off the outside of the big ring when on the gas.  Happened to me once when on the power when out of the saddle, and wasnt a nice experience...

HarryVolmer:

GT1:

re the 2.5 mm spacer to adjust the chainline:

is it just there to insure proper shifting ?

i would think that you should be able to adjust this through the front derailleur

nothing to do with shifting.... i have found if i dont run a 2 to 3mm spacer on the driveside, then the large chainring is too inward with respect to the 11/12 tooth gear.  This results in a too big an angle on the chainline when in 53/11, so you run the risk of the chain coming off the outside of the big ring when on the gas.  Happened to me once when on the power when out of the saddle, and wasnt a nice experience...

Harry,

I understand your concern and rightly so, nobody likes one of those surprises in a full blown sprint.  As for your thread title question, I have seen others on this forum post pics with the new Sram Red 2012 GXP crank (same as older GXP) on 2011 and newer bikes with BBright without reporting your issue.

However, what this boils down to is whether you have installed everything correctly (which it sounds like you have), but more importantly the combined dimensions you have across the BB area with all these parts.  We know BBright measures 79mm across, I don't know what the adapters measure both DS and NDS, but I guess in theory the sum of both adapters and BB cups with race caps/seals should measure what a typical GXP BB does in width.  If the numbers don't match, then something must be off.  I am not sure wether it is necessary to run those extra 2 to 3mm with spacers on the DS, but if the other numbers don't check (meaning shorter than GXP BB), then you definitely would want to use them to get proper chainline.

I am assuming you have taken a measuring tape or ruler to the the BB area and measured the chainline from center of seatube to center of chainrings as pictured below.  If I'm not mistaken BBright did not affect chainline, so in theory it should measure ~43.5mm for a double crankset.  If that is not what yours measures, then perhaps that should be addressed first.  As far as the NDS crankarm coming loose, well, that is obviously not good.  That being said, if the dimensions of any of the adapters don't check, then things are clearly going to be off on either side.  Measure, measure, check and recheck, maybe you got unlucky with adapters out of spec.  Good luck.

 

Thanks hutch for the indepth reply. Wrt the chain line issue, I haven't measured from the axis of the seattube, but have tried to mirror measurements between the big ring and outer chainstay of the factory FSA BBright and quarq cranks. The big ring on the factory crank was 16.5mm. I am running my quarq a little inward of this at 15mm, to try and maximize the amount of spindle exposed on the NDS. If I run the crank any further inward I have chain line issues with the chain dropping over the top of the big ring as previously described. Running the quarq any further outward results in insufficient spindle through the BB. As of tomorrow this shouldn't be an issue. Props to quarq as they fixed my bb30 quarq on the day they received it, posted it the following day, and it's scheduled for delivery tomorrow. That's Spearfish, South Dakota, USA to Adelaide, South Australia in under 72 hours!

Hi Harry,

Adding the spacer is the sole cause of the problems. You've withheld spindle legnth from the left arm, which directly caused all the issues you unfortunately experienced: left arm coming loose (never was tightened enough), bearing drag (tightening against the bearings, not the axle as intended), cup migrating inward (bolt tension acting against cup, not against axle as intended), bolt breaking (unsufficient preload on axle taper lets the joint move, putting the bolt in bending as well as tension, not tension only as intended).

The GXP system is robust when instaled as intended, but adding the spacer defeated the design intent with the resulting failures as you've noted.

The chain coming off the big ring is indeed a problem, but the solution you chose led to the other issues you encountered. Wish I had a different solution to suggest for chain staying on (stiffer rings???), but putting the spacer in obviously didn't work out in your case.

At any rate, your 30mm crank should be back to you by now, no problems there I'd guess! :-)

d_1234:

Hi Harry,

Adding the spacer is the sole cause of the problems. You've withheld spindle legnth from the left arm, which directly caused all the issues you unfortunately experienced: left arm coming loose (never was tightened enough), bearing drag (tightening against the bearings, not the axle as intended), cup migrating inward (bolt tension acting against cup, not against axle as intended), bolt breaking (unsufficient preload on axle taper lets the joint move, putting the bolt in bending as well as tension, not tension only as intended).

The GXP system is robust when instaled as intended, but adding the spacer defeated the design intent with the resulting failures as you've noted.

The chain coming off the big ring is indeed a problem, but the solution you chose led to the other issues you encountered. Wish I had a different solution to suggest for chain staying on (stiffer rings???), but putting the spacer in obviously didn't work out in your case.

At any rate, your 30mm crank should be back to you by now, no problems there I'd guess! :-)

I agree, the spacer is the sole cause of the NDS problems, however, without it the crank is unusable. further to the issues previously outlined, without at least a 2mm spacer, the crank will actually rub on the frame.

unfortunately without the spacer, the chain line doesn't approximate anything near that of the standard BBright crank.

Hi Guys, Heres some pictured from when i dismantled the GXP/BBright setup, and repaced the BB and reinstalled the BB30 Quarq. Before dismantling:

GXP-BBright Setup Chainline: Chainstay to Big ring measurment GXP - BBright Setup approximately 14mm (looks 15 but thats the camera angle and bad picture... Picture of non drive side (NDS) Note Cup looks like it is not pressed in far enough. This is because constant tightening of the crank pulled the NDS cup into the frame, flaring the outer shelf of the cup. It was removed and using loctite 609, pressed back into correct position, but the flaring of the outer shelf remained. Amount of exposed crank shaft on NDS = approx 10mm Drive side of crank, with 2mm spacer between crank and BBright adaptor (plus lots of grime!) BBright adaptor with 2mm spacer Drive side BBcup, and bearing cover & Quarq magnet GXP - BBright Adaptor reinstalled WITHOUT 2mm spacer Distance between Chainstay and big ring now 12 to 13mm (ie much more inward as u would expect) GXP-BBright adaptor WITHOUT spacer - crank rubing on quarq magnet and Drive side cup Chainline with GXP-BBright adaptor WITHOUT spacer ORIGINAL BBright FSA Crank Distance from chainstay to big ring - approx 14mm (apologies for bad pic) ORIGINAL BBright FSA Crank - NDS shaft 15mm BB30 Quarq Setup: Drive side with 12mm color insitu BB30 Quarq Setup: chainstay to big ring distance 14mm

HarryVolmer:

Harry, the pics are not that bad ;  )

Anyway, the fact that the NDS was flaring out and not flushed with the BB shell is definitely a problem because it shortens the length of exposed axle on that side.  As far as the DS... you know, it's tough to say what is going on there if 1) the cup is fully pressed and 2) the Enduro adapter is up to spec.  Theoretically everything should fit fine and you should still have relatively acceptable chainline (+/- 1-2mm).

I don't think this is happening, but by any chance... do you have some kind of spacer on the freehub body that would offset the cassette outward towards the dropout?  The reason I ask is because by looking at the pic below, it looks like a pretty tight fit between the smallest cog and the rear dropout.

Thanks Hutch,

The NDS cup is fully pressed in.  The flaring of the outer shelf of the cup was when the crank was over tightened and the cup migrated inwards. The cup was removed and pressed back in using loctite until the outer of the cup was flush with the frame.  The flaring of the outer shelf of the cup just makes it appear as its not pressed in far enough.  I couldnt bend the lip of the cup back to being 90deg to the cup as it would just crack and break.

With respect to the cassette, I am running the normal spacer supplied with Dura-ace cassettes on the 188 Zipp Hub.  I agree there isnt much space left, but i figured that was just standard.  I have checked the torque of the cassette lock ring and it is torqued to spec.