how freely should cranks spin.....

[ishaw]

.. .. when newly fitted without a chain. I've just fitted some e.thirteen cranks and it's all a bit tight. I've torqued it all up to less than recommended, and as far as I can tell, fitted the right amount of spacers.

Hmmmm, any thoughts?

 

[Matthews]

Re:

Pretty freely is the usual , not sure how e13 work but on the shim ones the common mistake is overtightening the funny plastic nut thing that pulls the crank onto the axle .

 

[ishaw]

Yes, my thoughts too. The nds has a few spacers and a wavy washer and when torqued up to less than the recommended, it's really stiff. My brain isn't working so hopefully someone can help confirm if this means I need to add or remove a spacer? These aren't the same as bb spacers, but fit in the gap between the arm and the bb. I'm thinking less, but not sure.

 

[02gf74]

give em a good push and I would expect at least 10 revolutions - there should be very little friction preventing them from spinning.

either incorrectly assembled or bottom bracket out if they are external bearings.

 

[ishaw]

I've followed the manual to the letter.

Spacer on drive side between frame and bb
Insert drive side all the way through bb
Fit nds arm. Nip up bolt and measure/fill gap with 0.5mm spacers
Remove nds arm
Fit spacers, but swap one out for wavy washer
Tighten nds to torque

This results in one tight bb

I've tried without the wavy washer, and still the same result pretty much.

I could fit without the 0.5mm spacers or add more, but instructions say that the minimum is one spacer, one wavy washer.

 

[jimo746]

did you have a feel of the bearings before fitting? check that they turn freely with the cranks removed.
If they seem ok then it must be an issue with the installation.
Problems I've had in the past have been to do with spacers and washers interfering with the NDS bearing when it's all been put together and torqued up (spacer was flat up against the bearing and causing friction as I turned the crank.)

 

[ishaw]

If I undo the nds bolt a little, it spins perfectly so it's definitely to do with spacers, I'm just following the instructions which is bugging me. I've read that some recommend using one less spacer, but that would leave none?

 

[jimo746]

Re:

hmmm... have you torqued the NDS bolt to spec? I don't think you mentioned what kind of BB it was? but my FSA mega-exo-thingumy only needs a tiny amount of torque on the bolt (so little in fact that it kept bloody working loose, so I resorted to using threadlock on it and it hasn't come loose since).
But if I tightened it up a "reasonable" amount the cranks would feel fairly stiff to move... back it out so that it was barely held in and they were fine.
In the end I borrowed a torque wrench, and applied threadlock.

 

[ishaw]

I've tightened it to less than the specified torque using a torque wrench. I can get to a point where it spins freely but its way below the specified torque and will undoudtedly work loose. The bb is proprietary to the crank, and I've never had a problem with normal ht2 style bbs. It's all a bit annoying, and I've yet to get to replacing the hose on my brakes yet. Another challenge ge to face after I get this sorted.

 

[mattr]

Is the bottom bracket faced?
If the cups aren't on the same axis there will be loads of drag.
Also, the long seal edge on the big ht2 bearings generate a fair bit of drag. (Even a factory installed dura ace is unlikely to manage 10 rotations. Maybe 4 or 5.)
I'd just try it with no spacers and see what happens.

Might be worth measuring the bottom bracket width accurately, there's a tolerance of a couple of mm within the spec for a BSA bottom bracket IIRC