Hi All,

Need to replace my 970 XTR cranks HTII bottom bracket and before I shell out the £32-40 on the XTR one was wondering if there are any other cheaper options like using the XT ones (with or without modifications) etc?

Thanks,

Chaz

Get the xtr one they last longer than the xt's for very little extra cost

Or get Chris King which costs £80 and lasts indefinitely.

Hmmm no bearings last indefinitely and there's been quite a few posts on here about ck's running roughly. Also its not 80 quid cos you need the grease tool too. Sure if you want the bling then ck's the way to go, but cost effective… I don't think so as you get a good 18 months out of a 32 quid xtr one.

Well fair play to the last XTR one that came with the cranks had it about 3 years and a fair amount of use and only now sounding like a rusty gate. I was more interested in knowing if they were physically comaptible with other versions (XT etc) as the XTR have a different method of going together?

Buy just the bearings as that is the only part you really need to replace.You can buy these cheaply on ebay and SS do some ceramic ones for about £30 a pair.They are really easy to change as well(if you know how).

Yeah the xt and the xtr will fit the same without any need to modify anything 😉 as said sick with new xtr one though.

theres no comparison between chris king & XTR. my original XTR lasted 7months. yes they're more expensive & you need the grease tool, but my chris king is coming up 2 years old despite stream crossings & many jet washes & its still silky smooth.

For a xtr to last 7months I suspect the preload was incorrect or the bb case needed facing. I'll get 18- 24 months out of a xtr in the lakes riding 2-3 times a week which as we know is a harsh environment. A king would have to last 8 years to be cost effective for me by which time it would be battered and I will have moved on bike wise and I suspect bb and cranks will have to. But as said they are bling so whatever floats your boat is good 😉

Does anyone know specifically which bearings I need for the cups?

Have a look at sending them to betd they will fit enduro bearings for you for free and send them back.

blimey thats good service if they fit them for FREE. 😯

6805-2RS mate.

The bearings you're after are 6805-2RS, or prefixed with an S for stainless steel types.

I've just order a couple of el-cheapo ones from AK Bearings as it's my first go at swapping them out. I'm not convinced of the need for super-high precision bearings as you won't be getting close to their design parameters in terms of RPM or loading – I reckon the sealing is more important so I'll try to pop off one of the seals & fully pack with grease before fitting.

http://www.mountainbikecomponents.co.uk/items.asp?CategoryID=237&Name=Hollowtech+II+bearing+upgrade

thepurist if you are not sure how to replace your bearings try my way!!When you get your bearing cups out place a internal circlip on the inside of the bearing(you will need a pair of circlip pliers).Sorry not sure of circlip but you can usually buy a bag of them cheap.Then place the cup with the bearing side down on a vice or two bits of wood.Make sure only the extreme edges touch the wood or vice so that the bearing has enough room to be pushed through.Then grab a 19mm socket and place in the inside of the cup and make sure it is resting on the bearing and then smack it out with a hammer.When putting your new bearings in place them in the cup and place the old bearing next to it so that then you can press them in using a vice.Sounds complicated but in reality it is simple.

It's a myth that you need the tool to regrease the CK BB. Instructions are provided to do the job without.

It's a piece of wee, doesn't need the BB removing.

Any hints/guides on taking the caps (without damaging them) off the XTR cups to get in to the bearings?

Cheers for the help guys

Fingers, from the inside of the bore.

Screwdrivers etc will just wreck them.

I replace my XT one's without taking the cups out of the frame. They are fairly easy to drift in and out whilst in situ.

bear-uk.HOW?