Need help with Ultegra cranks
 

I'm hoping this isn't a double post, but my previous try seems to be messed up. Anyway...

I'm hoping someone has an idea to help me out here. Last season I bought a new bike with Ultegra 10spd triple setup up front (Hollowtech external BB). Almost right away I noticed the cranks weren't spinning as freely as they should---there's a fair amount of resistance. With the chain off, I'd give the cranks a spin and they'd quickly come to a stop after making one revolution or less. All of my other bikes' cranks spin much more smoothly, and if I give their cranks a good spin, they rotate freely for at least four revolutions.

Shortly after I got the bike, I took it in to a couple shops to see what they thought. They admitted they didn't have much experience with the new Ultegra stuff but suggested it might just need a break-in period.

Now, a year later, the "breaking-in" hasn't done anything to free up the cranks. They still don't spin freely and will only make one revolution or less when I give 'em a push.

Any input?

Get your BB (bottom bracket) replaced.

Probably a reflection on the sealed bearings used in the cranks. Sealed bearings have built in drag that is a lot more than open bearings. Possible that there is some binding somewhere in the system, would be useful to compare with another bike. Finding a bike at an LBS with a similar setup shouldn't be hard, but if you are rotating with the chain off, a direct comparison will require supportive LBS personnel.
Steve

Steve: It doesn't seem like just the difference between cartridge and loose bearings, so I think I will just take it to the LBS again for a comparison. They're pretty good guys, so I'd expect they'd pop a chain off if necessary.

NoRacer: BB was brand new (as was everything else on the bike)

Perhaps the pre-tensioning cap was torqued down too much.
Loosen the crank arm bolts and loosen the tensioning cap. Does it spin better?
If so, torque the tensioning cap to 6-12 in/lbs and retighten the crank arm bolts.
Now does it spin more freely?

BlastRadius,

I'm actually in the process of overhauling the whole bike anyway, I just haven't picked up the proper tool for removing the cap and BB yet. Once I do I'll try your suggestions. How do I know the torque on the cap if I'm using the Park tool (BBT-9)? Just estimate?

The tensioning cap (Crank Arm Fixing Bolt on Shimano Exploded View) is something that you just have to go by feel. 6-13 in/lb is not a lot of torque.

Mine spins freely a few revolutions..........your's should too. May need to take off the crank and take a look at your BB.

Mine also spins "freely" - a few (<10) revs. I did notice that there is definitly more drag using this sealed cartridge bearing design than I am used to with bottom brackets. So much so that when I first stripped my bike after it was originally installed I assumed that the original builder had not adjusted it correctly....wrong. You know what the say about assuming....it makes an...well you get it.

Adjusted correctly these things just have a lot of internal drag...due no doubt to the viscosity and volume of the lubricant of choice. Oh well. The eingineer in me says "Drop the whole 'feel' thing and pick up a torque wrench, spec, and ride" While the lost art, locksmith side of me says "it just doesn't feel right"

:rolleyes:

My cranks also spin freely. What I would add is that my XT cranks (also HT2) were noticeably quite stiff when they went on and now are much more free at the BB, 500 miles on.

Note too that Shimano offers no wannranty on BBs whatsoever. A friend of mine had his for only 5 days before it needed replacement; Shimano said, "sorry, there's nothing we can do" and he had to buy another.

In lieu of a proper torque wrench I've used a spring [fishing] scale with the hook taped to a wrench and calculating the inch pounds of force from the length of the lever. Crude but it puts you in the ball park.