I can’t believe it the outer seal on driveside of my gxp crankset has loosened again even after having had the bb shell refaced which previuos mechanics obviosley hadn’t done.At another bikeshop they said I should switch to shimano as the gxp system is flawed.Could this issue be down to overgreasing the axle I cant open the friggin spindle bolt as :xit’s that tight.Do any good bicycle mechanics excist at all I am wondering or do they all just try to rip you off.

Is the bit you are referring to the black plastic top hat? Is it the original bottom bracket? I have this issue with my GXP system, but believe it is down to a new design bottom bracket being used with the older cranks. With use the seal migrates outwards onto the axle. I have bodged/fixed it by putting a small ziptie at the end of the axle to hold the seal in place. I think the problem is that the axle design of the new cranks must have changed slightly.

Yup, bin it and get an HTII setup.

I had play in my GXP crank arms after a while on my CX bike, and the bolt was silly tight. I fancied slightly shorter cranks anyway so used the opportunity to move to a new shimano setup which in my experience works just fine. I tend to get far longer out of my HTII BBs than I got out of that GXP one.

Edit:- it might seem like a pricier option, but no reason to go to your LBS with HTII I reckon. Just change the BB (or bearings) when it eventually wears out – easily done yourself with the right tool.

it’s a relativley new crankset a Sram s-1250(kind of like a stylo 3.3 crankset) it came with the black xr gxp cups with gutter seals technology .Since then I had another black xr fitted and 2 anodised grey team ones fitted.None of them lasted very long.The mechanic who did the current job said the reason it works its way out is because the bearing cups werent running paralell and the after having bb shell properley refaced the problem would be resolved.

Personally I don’t think the issue is with the facing of your bottom bracket, but I’m no expert. I’m betting the problem is only with the team cups? I’m guessing you didn’t have the problem with the xr ones? I only have this specific problem when using the Team BB with an older stylo crank. I feel sure the axle design has changed slightly.

Bearing life on my current team BB has been excellent, even with the bodge.

before going to this mechanic I bought an 8mm key and some grease to try arround on the knackered bb cups.Even thou I dont have a tightening toque key I never tightened the spindle bolt that tight that I wouldnt be able to loosen it again.The wiggling of the cranks only starts when the drive side outer seal comes loose.Since it is so tight I wonder if this mechanic did a proper job with the refacing of the bb shell or slapped grease on where it isnt marked blue in the gxp installation guide.Thatwhy I wanted to check but I can’t loosen it with my 8mm key.Its even tighter than with previous mechanic.

the 2nd black xr I had fitted by another mechanic went even quicker and he had covered my entire drive in grease.

maybe shimano is the better option but I only like shimano shifters and derailleuers.Just invested in new truvativ chainrings since I thought the problem would be resolved.

maybe thread in the spindle is already knackered and I should just gotten an entire new crankset

Strange. I hope you get it sorted. It does sound like poor facing might have been involved with the early failures, but I can’t really add any more re. the seal migrating outwards. I also found that the XR had poor life, but the Team seems much better, but with this annoying issue. Strange that you get play in the cranks when the seal comes out though… I don’t get that. There is a tiny bit of play in the system, but I do mean a really small amount. It has been that way for ages but runs quite smoothly and bearings seem good. I do have to do the crank pretty tight – I usually need a tap on the end of the allen key with a mallet to get it going.

p.s. I wouldn’t give up just yet, they’re pretty good cranks in the end!

yeah I might also try putting something at the end of the axle so the outer seal stays put.

You will need something like a bit of pipe or spacer to slip over the spindle. I couldn’t find anything quite right and was in a rush, so used a zip tie. It’s not 100% ideal as the head of the tie protrudes more than the rest of it, but it does work adequately until I can be bothered to change it.

I just managed to open the spindle bolt and just as I thought entire axle is covered in grease.I think excess grease could be the problem as it makes the contact point between the driveside bearing outer seal and the inside of the bearing race all slick.I am going to wipe away all excess grease and give the outer seal a good clean and see if stays put since bb shell is faced now.In sram gxp guide it doesnt indicate that you should grease the entire axle only at the end and the spindle.

http://www.flickr.com/photos/48790120@N07/8079671563/in/photostream/
excess grease on the inner race of the driveside bearing

the entire axle has been greased and not just areas indicated in sram gxp installtaion guide

Facing is likely not the answer, and in my opinion the design of the GXP loading means it should not need facing unless it’s way out. Plus a lot of decent frames are faced fine in the first place these days. It’s an LBS profitable business though 😉

For what it’s worth, most of them do this. It’s just the plastic dust cap (not really much of a seal). One solution is a spacer of some sort in the gap that you always get on the drive side (took me a while to realise this), but you want a soft flexible spacer, like rubber o-rings. Another is if it will work with your frame is to add a spacer on the BB cup on the drive side. That may explain why mine had one there when it shouldn’t have had, and since I removed the spacer the dust cap keeps working loose.

Long discussion on it here –
http://forums.mtbr.com/drivetrain-shifters-derailleurs-cranks/2mm-gap-truvativ-gxp-drive-side-728751-3.html

Oh and grease down the whole of the axle is not really going to be any harm. It’s barely in contact with anything in the middle. There’s the plastic cover of the BB that goes in the middle but it won’t contact the axle. It just really stops crud coming down the seat tube and onto the axle.

my frame’s bb shell definetley needed faced since I had been running Isoflow cranks powerspline cranks which came the bike(2006 Felt Q650) for years through loose rocks and when I took the bb cups of for the first time myself last month I could see that there hadn’t been any facing done by the previous workshops I had taken my bike to.When the new gxp crankset was first installed I specifically asked them to face and even if hadn’t reqeusted it anyone could see that it did needed to be done .The joke is they billed me for facing.The following two installations at 2 other workshops were also failure since they obviousley didn’t do facing either.This shop I am at now defintley did face the BB shell and the mechanic told me due to transport from Tawain to europe the temperature differences tweek the butting of bb shells.He had to take 1 mm of one side.The axle is maybe also worn off too much from it not staying in place.I am going take it to the shop as I hadn’t mentioned that to the mechanic.I just can’t imagine the gxp system doesn’t work properley since its used in racing over long distances where these issues would be unacceptable.It must be the axle which has suffered due to riding incorectley installed cranks.

I used to have this issue.
My solution was to space the drive side cup out with a black spire stinger. Then added a fat O ring from a rock shox rebuild kit to the base of the spindle to stop the seal migrating.
Has been good for a while now.

I love ranting clueless customers with mad conspiracy ‘theories’. Make sure you wear your tin foil hat when you go in so they can’t read your thoughts.

I am not going to comment on the issues above but one trick to getting gxp style cranks to work well is to refit them a few times with lots of grease at the intial instillation. They work like a square taper crank in that there is a interface fit between spindle and the non drive side crank arm fitting them a few times and torquing them corectly 48-52 n helps to make this fit correct. My exiperence is that most people don’t torque them correctly as well and they need to be tight to work well.

+1 on correct torque. Judging it by hand you can easily think “that’s surely enough” and it really needs loads more. Better to use a torque wrench though and do it to spec from the instructions. Getting the things off is more of a pain but I use a breaker bar which makes it easy (anything at all to give long leverage will do)

I had thermoplastic top hat thing constantly falling out making cranks loose. Just cut up an old inner tube to make some rubber washers. Works fine now.

It’s not SRAM cranks, but their bb’s that is the issue. To be honest, Shimano bb cups are pretty rubbish too.

Ive had a hope ceramic one(HT2 with hope GXP adapter) for my X0 cranks for 2 years with no issues at all. I do some spannering on my mates bikes, and all their GXP, HT2 and PFBB30 bb cups develop play after 3-6 months.

‘Grease in bearings’ shocker!

I don’t have a torque wrench so I can’t say if the spindle bolt had been overtightened or not.With the two last jobs done I had to stand on my 8mm allen key to loosen the spindle bolt.Seems when it is that tight that cranks do not spin so well.Could overtightening be the reason for the drive side outer seal to loosen.Is the recommended torque really that tight that you could imagine it to snap off?Why didn’t they make a deeper thread?Just trying some rubber band to prevent the outer seal moving.If it works great but I would still like to know why it can’t work without.

It’s very hard to overtighten the GXP. 50Nm or thereabouts is a hell of a lot, and far more than you may think. Standing on the allen key to loosen is about right. Probably the key you’ve got is a short length so you’re not getting much leverage and it should be very difficult, near impossible to loosen it with that. You need a wrench and maybe even an extension or a breaker bar to get the leverage.

Torque is that high to pull the non-drive side tight and flush with no play and to avoid it undoing itself when riding. The thread is all internal and plenty of it to do the job.

Overtightened wouldn’t be causing the ‘seal’ to work loose (but it’s not a seal really, it’s a plastic dust cap that’s all).

It’s just exactly as said, the dust cap on the BB cup for GXP is just a poor design.

And yes the Hope and similar BBs with GXP adapters are reportedly much better.

Another option is to try to get a replacement dust cap. As in that thread I posted above it’s suggested they are not manufactured equally and some can be loose and others snug.

the elastic band seems to do the job for now.I tested it on an over 3 and mile ride crankin high gears and and seems to stay put as opposed to before when it only took a few revolutions on the big chairing for it to come loose.I think the dustcap must already a wee bit damaged on the lip from not being place on a few rides.It is still hard to believe that gxp is flawed but atleast the bearings should last a bit longer.Still taking it the to the bikeshop tommorrow see what mechanic says since he assurred that after facing the bb shell everthing would be fine.Maybe he can to Sram and ask them whats up.

……but remember when it comes to Truvativ / GXP bottom brackets….
http://www.urbandictionary.com/define.php?term=turd+polishing

I was at the bike this afternoon and showed the mechanic what had happened also the photo of how the outer seal had worked its way out.
He said the only cause he can see is that surface of the axle has been damaged from using it with that kind of play and that there is the possibilty of sticking some sort special teflon tape on the area of the axle to make surface even again and eliminate any play.This way the outer seal should stay in place since the bearing cups are propeley alligned now.I also asked about the facing of the BB shell and he said no previous facing had been done as there was still paint rest on the lips apart from the dents and that in general shops should always face the bb shells of the bikes which they are selling even if its only because of the paint on the lips which can also cause problems with bearing cups being properly alligned .Another he thing told me is that if you use BB bearings from another manufacturer you automatically lose warranty on your chainset for any manufacture defects. Since he is going to do it free of charge I guess he also curiuos to see if it will work out or not because he only has high end bikes using gxp with ceramic bearings where unlike with conventional gxp bearings the drive side outer seal(dust cap)is firmly connected to the rest of the cup and it wont move.Pesonally I would be good to go with the elastic band solution since any noticible play has gone but we will see.I still can`t believe I had been billed for facing the of bb shell on the first installation and the following 2 bikeshops didn´t mention anything .Either they dont know or they haven’t invested in facing tools or they are just trying to rip you off when not preparing the bb shell correctley.

On the facing… check it yourself. You just need to make sure the two faces are parallel. A vernier caliper or something similar will do the job, or you can bodge together something to check.

I’ll bet they’re fine 😉

But anyway, with the GXP the cup alignment I would have thought is going to be based on the thread they screw into, not the faces (and I doubt the threads are out of alignment).

Personally I think you’re being spun a line by the shops.

1. You only need the shell facing if you suspect they are not parallel, especially with a screw threaded GXP that loads on one side. Else it’s a waste of money and you’re reducing the BB shell width – that in fact might have an issue on the seating of the dust cap!

2. The dust cap working loose is not a crank alignment issue, it’s just a well known issue with the GXP cups.

Personally I’d go with whatever rubber band/o-ring/etc solution and problem solved. If the bearings aren’t wearing and no play in the cranks long term, then the frame is fine in my opinion.