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Old 09-04-10, 04:18 PM   #1
mazdaspeed
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GXP bottom bracket questions

I just bought a truvativ elita 2.2 GXP bottom bracket.

The crankset is nice! The bottom bracket, however, seems cheap. It's working fine for now, but after reading about the non drive side loosening, I tightened it a little past spec to make sure that didn't happen (after a lot of research). I am slightly concerned that I overtightened it since I can see some of the celeste colored grease coming out of the ends of the external bearings, but it might just be the crappy seals I've read about. What do you guys think about that? The BB FEELS good though.

Secondly, are all sram bottom brackets the same? GXP I mean, could I upgrade this one to a better model in the future?
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Old 09-04-10, 04:39 PM   #2
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Actually I might not have even overtightened it or by much, since I used a long allen wrench rather than a torque wrench... maybe I'm just paranoid.
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Old 09-04-10, 04:40 PM   #3
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just ride it. the drive side loosens when the bearings die and sieze up.
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Old 09-04-10, 05:52 PM   #4
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just ride it. the drive side loosens when the bearings die and sieze up.
what?
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Old 09-05-10, 06:10 PM   #5
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Actually I might not have even overtightened it or by much, since I used a long allen wrench rather than a torque wrench... maybe I'm just paranoid.
Are you sure you hit the torque correctly? The actual amount of torque required on SRAM's stuff is fairly significant... I used an 18" long, 3/8" torque wrench to hit it on mine (very easily i might add) and was nowhere near spec with just a hex wrench. under-torquing will result in a loosened non-drive side arm eventually and that will kill the BB because of how SRAM/Truvativ cranks are designed.
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Old 09-05-10, 08:35 PM   #6
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I tightened it pretty good, enough so that I was uncomfortable putting any more torque on it. I would be surprised if it was less than 40ft/lbs. That said, perhaps I should get a 3/8" torque wrench sometime soon.

I was mainly curious about why I can see grease along the edges of the seals.
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Old 09-06-10, 04:40 PM   #7
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I have had grease show on both my Force-level SRAM BB and when I was using 6600 and 6700 Shimano BB's. Seems pretty normal to me as long as it's not flinging out of the seal.

And for the torque, I thought you were talking about the crank, just to clarify. The BB torque is not that high but the cranks require lots of torque to tighten. From my understanding, this torque is necessary because of how the crank centers itself in the BB using the non-drive side bearing.
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Old 09-06-10, 08:38 PM   #8
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Pure nonsense.

The GXP Bottom brackets suck, but proper installation with a torque wrench and they will NOT come loose.
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Old 09-07-10, 07:51 PM   #9
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I have had grease show on both my Force-level SRAM BB and when I was using 6600 and 6700 Shimano BB's. Seems pretty normal to me as long as it's not flinging out of the seal.

And for the torque, I thought you were talking about the crank, just to clarify. The BB torque is not that high but the cranks require lots of torque to tighten. From my understanding, this torque is necessary because of how the crank centers itself in the BB using the non-drive side bearing.
The torque spec for the non-drive drive crank arm was actually pretty low IIRC (lower than it should be to seat the crank I think). I know I have it tightened enough because it's been perfect over ~100 miles. I'm just going to remove the non drive arm and torque it down with a torque wrench to be sure.
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Old 09-08-10, 01:20 AM   #10
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Secondly, are all sram bottom brackets the same? GXP I mean, could I upgrade this one to a better model in the future?
There is the standard SRAM GXP BB (with steel bearings), then there is the overly expensive model by SRAM with ceramic bearings (marketing as part of the Red groupset I believe). There are not many options from other manufacturers, but I've been very happy using one by Hope - they make external BBs that are compatible with Shimano's HTII, but you can use one of these with some added sleeves in the non-drive side cup to make it compatible with SRAM's GXP, which Hope makes exactly for this purpose. I've been running this setup for over a year and am very happy. The bearings are stainless steel, and the crank spins exceptionally smoothly (much more so than any of the standard Shimano HTII BBs that I've worked on). I swap cranks around quite frequently (I have three SRAM and Truvativ cranks mounted with 33/48, 28/46, and 26/38/49 chainrings that I switch between depending on the terrain and speed of the ride) and have never had a problem with any crank coming loose after torquing it to the recommend spec' with the well-priced Park Tool beam-type torque wrench.
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Old 09-08-10, 02:00 AM   #11
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There is the standard SRAM GXP BB (with steel bearings), then there is the overly expensive model by SRAM with ceramic bearings (marketing as part of the Red groupset I believe). There are not many options from other manufacturers, but I've been very happy using one by Hope - they make external BBs that are compatible with Shimano's HTII, but you can use one of these with some added sleeves in the non-drive side cup to make it compatible with SRAM's GXP, which Hope makes exactly for this purpose. I've been running this setup for over a year and am very happy. The bearings are stainless steel, and the crank spins exceptionally smoothly (much more so than any of the standard Shimano HTII BBs that I've worked on). I swap cranks around quite frequently (I have three SRAM and Truvativ cranks mounted with 33/48, 28/46, and 26/38/49 chainrings that I switch between depending on the terrain and speed of the ride) and have never had a problem with any crank coming loose after torquing it to the recommend spec' with the well-priced Park Tool beam-type torque wrench.
That's good info, I'll look into the hope BB for sure once my current one dies (I wonder how long it will last?). I like the idea of the GXP system, so I'm going to get a torque wrench just to make sure everything is torqued correctly.
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Old 09-08-10, 02:02 AM   #12
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Oh, and is the hope BB serviceable?
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Old 09-08-10, 03:30 PM   #13
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gxp

GXP options:

Chris King
Enduro- send your cups to them or, buy a complete BB.



http://enduroforkseals.com/id228.html
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Old 09-08-10, 11:47 PM   #14
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The Hope BBs are fully serviceable, which is another advantage over the Shimano version. There were videos on the Hope website showing you exactly how to do the servicing, how to install the GXP adaptor sleeve, and many other things, but all the links to the videos seem to have disappeared at the moment or I cannot find them, hopefully they'll be back soon.
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Old 09-09-10, 10:44 PM   #15
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I've been thinking about buying the same crankset, any comment on it besides the bottom bracket?
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Old 09-09-10, 11:56 PM   #16
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I've been thinking about buying the same crankset, any comment on it besides the bottom bracket?
The crankset itself is super nice. I am extremely happy with it considering it has performed nothing but excellently, I was just a little worried about the bottom bracket since I've never had an external bearing type. It looks a lot better in person that in the pics online.

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Old 09-10-10, 02:08 AM   #17
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I've been thinking about buying the same crankset, any comment on it besides the bottom bracket?
I have experience with the Truvativ Rouleur, but not the Elita. The chainrings on the Rouleur are not nearly as good as Shimano's chainrings (not as stiff and don't shift as well). However, because I use custom-sized rings on all my cranks (mainly from TA Specialites), this hasn't bothered me (I sold the stock rings to a friend for a pretty cheap price).
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