Fitting Cranks - grease the bolts?

[tdr1nka]

Simple rule of thumb, don't use anything with 'Loctite' on the tube/tin if you want to undo a bolt ever again without any bother.

 

[Proto]

Simple rule of thumb, don't use anything with 'Loctite' on the tube/tin if you want to undo a bolt ever again without any bother.

Tea Drinker is talking rubbish. Use the correct grade of Loctite (there are lots) and you won't have a problem.

By greasing the tapers you encourage the crank to engage on the taper further than it is designed to do, putting undue force onto the aluminium, and promoting cracking in the corners.

 

[tdr1nka]

Tea Drinker is talking rubbish. Use the correct grade of Loctite (there are lots) and you won't have a problem.

It was a joke btw.

Anyway yes, there are different grades of Loctite but many, newbies especially, are not necessarily party to that info.
From experience of working on cars and bikes, some 'threadlock's' can be a nightmare to shift without decent tools and a decent place to work, eg; pref with a bench or work stand and a vice.

For the standard fettle in the hall @ home, a light brush of the the bolt thread with copper grease and tightening to the appropriate torque should really be enough.

If there is a real need to lock the thread, eg; your bolts are working loose, then the threads may be worn, have been cross threaded or even the bolt slightly the wrong size.
Using Loctite in this situation would only be a quick fix and a temporary solution.

 

[Proto]

It was a joke btw.

Anyway yes, there are different grades of Loctite but many, newbies especially, are not necessarily party to that info.
From experience of working on cars and bikes, some 'threadlock's' can be a nightmare to shift without decent tools and a decent place to work, eg; pref with a bench or work stand and a vice.

For the standard fettle in the hall @ home, a light brush of the the bolt thread with copper grease and tightening to the appropriate torque should really be enough.

If there is a real need to lock the thread, eg; your bolts are working loose, then the threads may be worn, have been cross threaded or even the bolt slightly the wrong size.
Using Loctite in this situation would only be a quick fix and a temporary solution.

A joke. Ho, ho, my sides are splitting. As you say, newbies are not be aware of the different grades. Why joke and misinform.

As a general rule, I too copaslip just about every fastener on my bike, car motorcycle, but to say:

If there is a real need to lock the thread, eg; your bolts are working loose, then the threads may be worn, have been cross threaded or even the bolt slightly the wrong size.
Using Loctite in this situation would only be a quick fix and a temporary solution

is just wrong. In some situations with vibration or cyclical (ha!) loading the Loctite can be more beneficial than overloading the threads themselves.

 

[tdr1nka]

Do you own shares in Loctite or what?

As we both agree that loctite is applicable in some situations I feel my experience/opinion should be taken only as that.

FWIW I simply said that you don't exactly need thread lock and it can be a b*gg*r to free off. How exactly is that misinformation?

 

[Proto]

You earlier said:

Simple rule of thumb, don't use anything with 'Loctite' on the tube/tin if you want to undo a bolt ever again without any bother.

Yet now you say it's applicable in some situations.

FWIW I simply said that you don't exactly need thread lock and it can be a b*gg*r to free off. How exactly is that misinformation?

 

[rustychisel]

I'll jump in. By and large, Loctite is the first resort of the lazy mechanic. Even with modern materials it's largely un-needed.

 

[mickle]

I'll jump in. By and large, Loctite is the first resort of the lazy mechanic. Even with modern materials it's largely un-needed.

Agreed.

 

[rustychisel]

Thank you. You're very gallant.

 

[tdr1nka]

Yet now you say it's applicable in some situations.

As a temporary fix I said 'maybe' use thread lock, just not as a general rule. You say it's ok to use if you use the right grade.
This would suggest that we both agree that it is 'applicable in some situations'.

12 years experience of working on things mechanical, I would honestly advise against the use of thread lock on bicycle parts if only to save barked knuckles, damaged tools or worse, sheared bolts and an unrideable or unsafe bike.

I was trying to say all this in a lighthearted manner as is my usual mode, you appear to have got in a snit, which is of course entirely your choice, but then you openly rubbish my humble but equally valid opinion in preference to your own. Not exactly friendly, is it?

Quick tip Proto, next time you are feeling 'liberal with the loctite' check your hands throughly before you go to the toilet just in case you accidentally lock yourself up.

 

[Proto]

I was trying to say all this in a lighthearted manner as is my usual mode, you appear to have got in a snit, which is of course entirely your choice, but then you openly rubbish my humble but equally valid opinion in preference to your own. Not exactly friendly, is it?

No, and please accept my apolgies. I have no excuse for being a bit snotty other being just a tired, grumpy old man.

However, without wishing to stir the pot too much, I would suggest that Loctite make fantastic products that work very well. Industry would grind to a halt without it. Countless FSA chainset owners can't all be wrong

BTW, I've got a lot more than 12 years engineering experience behind me. A rather terryfying amount more.

 

[tdr1nka]

Apology accepted.

 

[betty swollocks]

To grease tapers or not?
Highpath Engineering - Cycle transmission specialists say and I quote:-

Always clean and lightly grease the axle tapers or splines before fitting cranks. This contradicts advice which is often given, but anyone suggesting that grease shouldn't be used either doesn't have much mechanical understanding or has a vested interest in shortening the life of your cranks.

 

[coldash]

The Campag instructions that came with my crankset say

Before you assemble the cranks on the bottom bracket axle, degrease the axle and crankset square heads thoroughly.
NEVER (their capitals and bold) lubricate the bolts before tightening them.

but I used Copaslip anyway

I've never had any problems using Copaslip but have had plenty of problems with seized threads where it hasn't been used.

 

[Proto]

I'll see your Highpath and raise you a Campagnolo

http://www.campagnolo.com/repository/documenti/en/7225254_Crankset-07-05.pdf

Top left, page 28.

edit: Bugger, Coldash is too quick for me. Must tripe faster!