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I've got some play in my cranks and want to confirm my diagnosis before shopping...
The arms appear to be tight on the spindle, and that whole section moves together. But there is a small amount of movement between the spindle and BB cups, it doesn't grind or knock in use as far as I can tell, but its noticeable when checking the bike.
I would tie this down to the bearings having gone in the BB cups, although i've only had hollowtech cranks for a few months so want to make sure. They are probably a good couple of years old, and I cant confirm what state they are in as I dont have the tools to remove them.
Good diagnosis? Or could it be something like a damaged/bent spindle etc?
you mean old hollowtech - single bb unit with an axle stub sticking out either side ?
don't think you can open them up to see the bearings
IME they don't fail as fast as the hollowtech2 bbs - i'd keep running i 'til it starts to grind/knock
(check it's in tight - retaining cup on non-drive side ? Prob easiest to remove everything, regrease threads & put back; you'll get a better idea of how smooth it actually runs when it's out too, I reckon)
Are we talking Hollowtech or Hollowtech 2 (The latter has a hole right through the centre of the crank and bottom bracket) I would be surprised of a hollowtech BB had play as it is a sealed unit however you can replace it pretty cheaply. Shimano ES25 i think. I have one in the garage with about 100 miles on it that you can have for a beer and postage. If it is hollowtech 2 there will be two allen bolts on the non drive side and a plastic screw in the crank arm. If this is the case I would pop the cranks off and check for play and replace if necessary. I can't see any danger in riding it in the short term
Its a Hone crank, I obviously missed that relatively major detail...
Which makes me think its Hollowtech 2... I will have a check but I'm sure Hone was introduced onto the latter system...
I dont want to take it apart if i dont have to as I dont have access to the tools to tighten it back up and my LSB's are pretty pants.
Yes it's hollowtech2 and what you describe sounds exactly like needing a new bb.
just a word of warning, had two mates who thought riding a worn BB wouldn't do any harm, both actually had loose cups which fretted away the threads in the frame, and left them with a large repair bill.
I was more worried that a borked BB would take the spindle and cranks with it...
I'll be doing some shopping for a new one plus tools then I think! It's put the plans for a new headset back a while unfortunately...
If the inner race soils the bed and spills the ball bearings, it will take the axle with it.
[url= http://farm6.static.flickr.com/5022/5672639445_7b216a9751_z.jp g" target="_blank">
[url= http://www.flickr.com/photos/21634402@N07/5672639445/ ]XT Crank with bent axle.[/url] by [url= http://www.flickr.com/people/21634402@N07/ ]ben_oggles[/url], on Flickr