bronaugh

Hi folks,

I've just killed an XT ES-71 bottom bracket in about 18 months, and I'm a little disappointed by that. So I'm in the market for a crankset/BB that'll hold up to my abuse.

For some context: I weigh about 140lbs, I ride with clipless pedals, and I kill my chain about every 4-6 months (~2000-3000km). I ride in nasty, wet conditions about 6 months of the year; I do XC / light freeride / commuting on my bike (I commute on the bike in wet weather to save the dainty road bike). I also tend to wear things out instead of break them.

In terms of interface / bottom bracket type, should I go square taper? ISIS? Outboard?

Can someone recommend specific models that they've had good experiences with?

Thanks!

Drew12

With the conditions you mention, feel good about getting 18 months out of a BB.
IMO of course...

MattP.

What is your budget?

bronaugh

For a bottom bracket, under $150 (but at that price it had better last 10 years).

For a crankset, under $250.

Basically, I'd like to spend less than $250 on the whole system. I don't intend on racing or anything; I just want something rock solid, moderately light, and reliable.

ghettocruiser

Ceramic BB's tout longevity among their attributes.

You may have to be the guinea pig, however, as I'm not keen on spending the $$$ to find out yet.

mcoine

I have a brand new shimano (fc-m542) 2 piece crankset/bb with external bearings for sale right now on ebay for pretty cheap. Let me know if your interested and I'll put a buy it now on there.

bronaugh

This is kind of tangential, but can someone either describe the compatibility between RaceFace/Truvativ/FSA/Shimano's road/mountain outboard bearing setups or link me to a document describing it?

Thanks.

mcoine

The new 2 piece cranksets with outboard bearings are sold with the bottom bracket. With the shimano's I swapped out for FSA's, the bb looked identical, but FSA says to only use FSA bb's with their cranks, and I'm sure shimano says the same. Just buy a new set and forget about it.

never

I have mix-and-matched cranksets and external bottom brackets. They are all interchangeable.

bronaugh

Yes, interchangeability was exactly what I was asking about -- just want to make sure I'm not going to be stuck with a system which only one vendor makes bottom brackets for.

Thanks.

MattP.

Shimano XT's nuf said.

colombo357

Why fret over a $40 bottom bracket that lasted 18 months (a long time)? Get another identical BB and keep riding.

bronaugh

Yeah, my last crankset was also Shimano XT (M752). They work great overall; only issue with the crankset itself is the clicking, which is enough to drive one to drink. So I have a secondary reason for upgrading.

Plus, I only have 1 choice of vendor for BB; I don't really like that, since the BB doesn't last all that long. For those who say 18 months is a long time -- read up on Phil Wood and Syncros double-row bottom brackets. A friend of mine has a Syncros double-row that's working just fine 10 abusive years after he got it. Main problem is that they aren't made any more and they're square taper. Likewise Phil Wood is square taper.

MattP.

Sure it wasn't your pedals? Proper installation and care, the cranks/BB shouldn't be clicking.

bronaugh

Happened with both Eggbeater SLs and Shimano PD-M737s. So it wasn't the pedals.

If you read reviews on the M752 cranks (or pretty much any other Octalink crank) you'll hear about the clicking. About half the cranks do it. It seems that greasing the spindle every time it happens shuts it up for a while, but it always comes back. Some people claim various miracle cures, but nothing is 100%. It could be an installation problem (I didn't torque the cranks with a torque wrench, as I didn't have one at the time) but I did tighten it as much as I could when I installed them.

bronaugh

As a denouement to this thread, I bought myself a Shimano XT M770 crankset -- I'll swap the bearings for something more durable when I kill them.

Drew12

Why ask the question if you have the answer?


And on the XT770..
I have a set and they seem to work just fine.

goldfishin

make sure that crank isn't wobbling on the spindle. mine is now and i'm planning on buying some new cranks.

bronaugh

Because it's not -the- answer, it's simply -one- answer -- and given that the BB in question is square taper, IMO not a very good answer.

As to the crank arm wobbling on the spindle -- nope. When I move one arm, the other arm moves -- thus the connection between the axle and the crank arm is fine on both sides.

I also checked that they were torqued properly with a torque wrench last night, and they're both tight as per torque spec.