Do I or do I not?
<backs slowly away from the thread>
Can of worms....
You'll find one or two old threads regarding that question on here. 🙂
I shall order another beer before this gets going.
I don't and have not as per Royce instructions
But .......
no
use the royce method of putting the crank on and torqueing, then ride it for some short bursts and keep retorqueing between each burst. Eventually it will not want any more torqueing.
The aluminum of the cranck provides enough lubrication to move the crank onto the interference fit crank.
No, in my view.
The bolt brings the two tapers together to form an interference fit. Grease will only help to loosen it when not needed. When needed,the right tool has always worked for me.
Grease makes it a tighter fit so yes, grease.
...awaits small flurry of inaccurate reasoning...
use the royce method of putting the crank on and torqueing, then ride it for some short bursts and keep retorqueing between each burst
so, you:
1 do it up
2 ride it, with it being too loose to be properly held on
3 go to 1
until it "stops being too loose"?
utter barking tosh
Yes
No
A tiny bit
Loads
I say no,
but the man from Del Monte he say yeeeeeeesss!!!...
In reality it makes sod all difference,
Potentially the crank will pull on a tiny bit further if the taper is greased, but so will over-torquing it.
Follow the crank manufacturers torque setting and re-tighten after riding up and down the street a bit.
this has been done to death and the answer is no.
[i]runs into thread[/i]
Don't use grease, if anything at all use antiseize such as copaslip or Park Tools ASC-1 if you prefer overpriced bike specific antiseize and torque to manufacturers advice
[i]runs back out of thread with hands covering ears[/i]
I've had conflicting advice from various sources such as blingy crank manufacturers and blingy bb manufacturers which has led me to discard any information received and believe in my own judgment, whether that be correct or not.
I've a set of middleburn square taper cranks from 1993 still going strong on a royce BB, i used copaslip and a torque wrench.
I say yes, my middleburns and white industries cranks always loosen and loosen and loosen if they aren't installed with a thin smear of grease...
They then stay tight but also come off easily when required.
Edit: I use copperslip, not grease, as per somafunk
It's all about getting the correct torque on the bolt. It may happen that you get the torque without the tapers being 'correctly' aligned, in which case copperslip or grease may help. It's also possible that you get a good fit without help.
I don't use any and I haven't had a problem.
this has been done to death and the answer is no.
Don't think so... [url= http://draco.nac.uci.edu/rbfaq/FAQ/8f.11.html ]Can't believe there is still a need to link this after 23 years[/url]
Don't use grease, if anything at all use antiseize such as copaslip
Both things will have exactly the same effect in this case - sorry Kenny.
Don't use grease, if anything at all use antiseize such as copaslip or Park Tools ASC-1 if you prefer overpriced bike specific antiseize and torque to manufacturers advice
What that man said^^. I've always added a wee dab (match head) of cheap antisieze. Never had a crank fall off or fail to come off when wanted.
I put a smear of grease on, then wipe it off again. That way everyone's happy.
Grease, i have fitted over 30 on my own bikes over the years all creak free and come off again easily ish.
Dont blather it, just a brush on covering.
Tighten as hard as you dare.
New shimano square taper bbs come packaged with a little bit of lithium grease on the tapers... Just saying!
utter barking tosh
I believe that is what Royce advise.
i don't grease as such, more thin smear of something. Pedals though!!! LOTS OF ANTI SEIZE, learnt the hard way.
Anything I may want to remove later gets greased.
I have a titanium spindle on my BB and so if the crank is not fully on it will creak, whereas you don't notice for a steel spindle.
The Royce method I described is easily the best method as the crank is solidly on once you are finished retorqueing.
Greasing the spindle is less successful long term.
People also suggest that greasing pulls the crank on further than it should.
No grease. Bolts under high torque stretch, so you can try the following technique: tighten the crank bolts to the recommended torque (e.g. 45 N m) with a torque wrench; slacken off and then re-tighten - you'll find the wrench goes round a few more degrees than the first time; wait a short while and tighten again. Job done.
Bolts under high torque stretch
I highly doubt you're taking the bolt past it's elastic limit - and if you are you have problems.
I'd guess what's happening in your situation is that the aluminium crank is galling slightly on the steel axle, this then beds in slightly with the pedal oscillation, requiring further tightening.
A dab of grease would prevent the galling in the first place.
Dammit, got sucked in 😉
I highly doubt you're taking the bolt past it's elastic limitYou're right: you're not taking it anywhere near the elastic limit, you're accounting for stretch that takes place before the limit is reached.
I don't understand - yes, the bolt stretches a fraction as you tighten it, but are you saying it stretches more with riding?
don't understand - yes, the bolt stretches a fraction as you tighten it, but are you saying it stretches more with riding?Because of the stretch, the bolt will loosen after initial tightening to below the original torque spec. By using the above technique, the bolt will remain at 45 N m and the cranks will not loosen subsequently.
My understanding is that the use of grease causes the crank to slide further onto the taper than designed, deforming the crank/axle interface on the softer crank to a degree.
**** it . Just use carbon assembly paste 😉
Because of the stretch, the bolt will loosen after initial tightening to below the original torque spec. By using the above technique, the bolt will remain at 45 N m and the cranks will not loosen subsequently.
This, the stretch in the bolt will push the crank up the taper a bit more as it works, meaning that the tension in the bolt is reduced.
I always used to wipe with a greasy cloth then tighten them right up, they stayed on, tight and creak free and came off again fine when required. The crank extractor threads just aren't strong enough in many cranks to deal with pulling the crank off if they were dry and had corroded at all. Copper grease / anti-seize would also be fine.
My understanding is that the use of grease causes the crank to slide further onto the taper than designed, deforming the crank/axle interface on the softer crank to a degree.
I was always kind of depending on that. You'll never get a better fit between the two parts than you get if you get a little compressive yielding on the contact faces of the crank. Machining tolerances mean that the only way you can guarantee full surface contact is to yield the crank slightly. In my opinion this is much more desirable than leaving it sitting on the high spots and vulnerable to fretting, the risk of splitting the crank is much smaller than the risk of ruining it by means of the taper being damaged as it moves on the axle if it isn't really tight.
Because of the stretch, the bolt will loosen after initial tightening to below the original torque spec.
Yes, it loosens because the crank wiggles a little further up the axle.
When you tighten the bolt, the system reaches an equilibrium where the tension of the bolt matches the friction and compression of the crank. But that friction is artificially high because of the galling of the aluminium, so the friction reduces with use, causing an equal reduction in the tension of the bolt - so you find you can tighten the bolt further.
Remove that friction with grease, and then you're left with the compression of the crank matching the tension of the bolt, which won't loosen up and require retightening.
deforming the crank/axle interface on the softer crank to a degree.
Yup, that's exactly what you want to happen. It's not a friction fit, it's a compression fit.