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  1. #1
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    Bottom Bracket for the big boys

    Ok, on my 11 S Stumpjumper 9er ive been through three of the GXP bottom brackets.

    What have you guys been using?

  2. #2
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    I also had bad luck with GXP bb's. I would suggest you face and chase your bb before spending money on a new one.

    Hope or Chris King should be your best options.

  3. #3
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    Yep, just replaced my GXP in Sep. Went with a Chris King.

  4. #4
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    I have used many different brands of BBs, I dig outboard BBS... With the right tool (see RWS), you can replace the bearings in the cups instead of buying a new BB assembly, and Enduro bearings makes a great replacement no matter what your budget (Zero if you can swing it.)

    NOW... as a former big Clyde and now a barely Clyde, I have switched to the Enduro XD-15 BB...

    MOST modern BBs use cartridge bearings, which are not particularly fond of axial loading... which BBs routinely see in MTB. Putting axial stress on a cartridge bearing is not a good thing.

    The XD-15 uses a bearing that gives you the friction benefits of a hybrid ceramic cartridge bearing and the axial load stability that you would get from a true conical bearing... (there is a reason that Shimano uses conical bearings in many of their hubs... they are VERY durable)

    Now... the XD-15 is NOT a "fire and forget" part... You can't just throw it in there and get max performance out of it...

    The XD-15 needs to be torqued JUST to the point that you eliminate all lateral play... That yields perfect placement of the balls on the races with minimal friction.

    Now... you ALSO have to achieve a minimum torque on your crank bolt to insure that your crank arms stay tight...

    The KEY to having a sh!t-hot performing BB/crank setup with super low friction and all but bullet proof endurance, is to arrive AT your crank bolt minimum torque at the same instant you also JUST reduce BB lateral movement to ZERO. This requires some patience and mechanical skills/logic.

    Basically, you need to provide custom spacer setup in the BB installation to achieve this... You can do this in TWO ways...

    1) adjust the spacing between the cups and the BB shell (assuming you have a 68 mm BB shell). I haven't set up a 73 mm BB shell install yet). This is the way to go to make the "gross" adjustment (meaning the biggest amount). This is especially the way to go if you need/want to custom tune your chain line.... which I HIGHLY recommend... nothing better than a custom tuned chainline for eliminating those pesky shifting problems)

    Best way to do the adjustments here is to have EXTRA 2.5 mm BB spacers... I took a bunch of my extras I had laying around, and machined/lapped them down to the desired/required thicknesses)

    2) You can adjust the spacer/shim thickness between the crank arm and the outer bearing race. This is a great place to do your close tolerance adjustments (say you need to increase or reduce torque by just a few Nm or so to get in spec.) I used the included spacers, but I am also getting a collection of peel to fit shims (for setup), and a collection of various thicknesses of single-piece shims for my workbench... for future installs.

    A. If you reach crank arm torque before eliminating lateral play, then you increase the shim stack. (Add shims either between the cup and shell or between the arm and outer race... location depends on what give YOU the best result... do whatever improves your chainline (drive side), or keeps it the same (non-drive side).

    B. If you eliminate lateral play before achieving crank arm torque spec, you need to reduce the shim stack (either remove a spacer/shim from somewhere, or machine/lap a spacer's thickness down... again, location of the change depends on where you need it.)

    I know... sounds like a lot of trouble, but it isn't... and it IS worth the effort.

    It took me about an hour for the initial setup, and two additional rides and adjustments to get everything settled in... but...

    1) I have zero lateral play and am right at the crank arm torque spec...
    2) I have a procedure where I measure BB friction with a "spin test". My RaceFace BB gave me a 9 revolution measurement; my SRAM GXP gave me a 7 revolution measurement.... My XD-15 BB after proper setup gives me a 17+ revolution measurement... a SIGNIFICANT friction reduction, and rock solid lateral and axial stability.

    I can't say enough positive stuff about the XD-15... I will never use anything else. AND they have other types... BB30, PF30, et al...

  5. #5
    turtles make me hot
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    Chris King here. Been on the bike for a few years now.
    I like turtles

  6. #6
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    King, just like the hubs and headset with proper care will last a few frames.
    If I disagree with you, it's because you are wrong.

  7. #7
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    Try Enduro bearings from Real World Cycling in Tucson. I replaced the BB92 in my Pivot with one a while back and it's been better than the XTR that came in the bike.

  8. #8
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    When I first read your response, my reason for purchasing this BB, mainly the ease of installation and use, became obsolete. I got tired of adjustable chainline BBs back in the early 90's after too many chains breaking and getting stuck between the rings and frame. Watching the install video for the XD-15 BB through Enduro, they just thread it in and go; no mention of the spacers what so ever. Seeing this I thought great, no hassle. I installed the BB and the cranks, and then road around my court to test, and every time I test road it came loose. Then I stumbled upon your post, which really discouraged me until I thought about it a little. My old BB, which was a Dura Ace model modified with Ceramic Speed bearings, had bearing caps on either side. These had some width to them, even if it was minimal, so I just arbitrarily grabbed two of the thickest spacers included with the BB(the ones that go between the crank arm and bearings) and it worked perfectly. It still bothers me that they don't mention the spacers at all in the install, but it definitely wouldn't stay tight without them. I may try to mix up the spacers, maybe using the slimmer one on one or both sides. Thanks for taking the time to draft this comment, it really helped when I searched for issues.

  9. #9
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    I have the Enduro XD-15 bearings, both in BB30 and Shimano Hollowtech II style. The Hollowtech II's have been pre-loaded to 3Nm, rode them for a few miles and re-torqued to 3Nm, did this up to three times. if you wiggle the crank, you can see the seals moving up and down. Yet, after a 40 miles they still start creaking - drives me nuts. Going to take them off.

    Same for the BB30 version - you really need to apply quite some pre-load, and even then creaking slips in.

    I've lost faith in the Enduro XD15's - going back to the Chris King & Truvativ BB30 ceramic.

  10. #10
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    Having worked for a manufacturer of the ball in the ball bearings, I can honestly say that ceramic bearings are a gimmick, unless your bottom bracket spins as fast or gets as hot as a turbo in a car, or a turbine engine. A good quality stainless steel bearing is more than enough.
    “Think of bicycles as rideable art that can just about save the world.”
-Grant Petersen

  11. #11
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    I'm actually having the same problem. Everything feels plenty snug with no wiggle, but I develop a squeak in climbing gears under torque. Going to have a shop mechanic take a look, but I'm starting to feel the same way.....back to Chris King. I'm not really concerned about the ceramic bearings, I just want something I can put in the bike without having to adjust much. Enduro's installation video looked easy enough, and showed nothing about the spacers or pre-load, and now it turns out it needs a little more attention then I have time to give it right now.

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