I bought a set of these cranks a year ago; followed the installation instructions, didn't use a torque wrench but was quite conservative in tightening the main bolt. After a couple of months I noticed a bit of fore and aft movement and on inspection of the non drive arm splines I noticed a bit of deformation. the splines on the steel axle are in immaculate condition.

I've since replaced the non drive crank arm and it appears that the same is happening again.

has anyone else had a similar problem

didn't use a torque wrench

quite conservative in tightening

There's your problem. You don't want to be conservative on that bolt.

From parktools site

(45-54 Nm), which is a substantial load. A torque wrench is recommended

But the splines of the crank arm appear to have engaged the splines on the axle as much as they can without grounding.

I never use a torque wrench but I practically stood on the allen key to get a whopping load on it.

Your joking right?

That bolt would appear to require a torque of "two grunts and a groan". It probably came loose.

They're not joking 45Nm is 4.5kg of force on a metre long tool – that's a lot!

Did you not maybe think a torque wrench may be sensible after mullering one crank!? You may find it's just come loose again and that by tightening it properly you will get 'past' the damaged splines. Or you may not!

I thought a torque wrench would be handy, but that's another £150 quid..not all wrenches are equal.

But I've only got an 8" tool. I guess I'll need to hang a little over 22kg from it?

Thanks chaps I'll give it a bash.

Even using a torque wrench they still advise checking it again after a couple of rides.

Buy a torque wrench.

"But I've only got an 8" tool"

That's quite enough vicar.

I've got a £10 torque wrench which is fine for the sort of load you're looking at here.

seanoc – Member
Your joking right?

No. If I was joking I would have said

"A horse walks into a bar and the barman says why the long face?"

But I didn't…

Gutted that i was beaten to the "I've only got an 8" tool" quote.

Oops. Dumbass!

If you're gonna buy xtr why not get a torque wrench to make sure you fit it properly.

So then, to summerise; you f**ked up the installation of a £350 set of cranks because you didn't use the right tool to install them correctly, you replaced a crank arm and STILL didn't do it right, and it's doing the same thing as before, and you wonder what the problem might be?

If you're gonna buy xtr why not get a torque wrench to make sure you fit it properly

yep; you're talking to a man that bangs CK headsets in with a lump hammer and a dodd of wood.

So then, to summerise; you f**ked up the installation of a £350 set of cranks because you didn't use the right tool to install them correctly, you replaced a crank arm and STILL didn't do it right, and it's doing the same thing as before, and you wonder what the problem might be?

I guess so; it's been answered now though so thanks.

yep; you're talking to a man that bangs CK headsets in with a lump hammer and a dodd of wood.

Hehe – I've got a headset press and that was for installing a £20 FSA Orbit headset. 🙂