What's the best threadlock to use for MTB chainring/rotor bolts for example? Didn't want to end up locking every bolt on the bike completely solid.
none. just use grease.
I've had them work loose in the past though.... 😕
loctite 222 for me.
Blue Loctite. If you live near an airfield, I'm sure there will be a stall on your local car boot sale full of Loctite and exotic greases etc. at surprisingly keen prices.
It has an expiry date on the bottle, doesn't seem to "go off" at all (and Loctite have said as much), but you're not going to chance a plane crashing because you used a bottle of old Loctite.
To be honest it doesn't matter much, so long as you're using removable threadlock compound. If you use stud grade (ie, for fixing studs into engine blocks etc, not for manly men), then your discs will be staying on the bike for a very long time!
FWIW Blue normally means "medium" or removable, Red is stud grade...
Loctite 222 for me, middleburn use this for their chainring bolts.222 is low strength needing 6Nm torque to remove and 243 is the blue medium Loctite which requires about 36Nm torque to remove so a little overkill.
Loctite 248 pritstik style pen for me. £8 or so at halfords.
Agreed - 248 is much easier to use than the runny equivalent (243).
Thanks all. Will stay away from the red stuff then.
"THREADS, THREAD-LOCKERS, GREASE AND TIGHTENING TORQUES
One of the most debated issues is the coupling of threaded parts; in particular it is debated if threads should be a) degreased or b) lubricated or c) treated with thread-lockers, and what is the proper torque to be applied in each of these cases.
In line of principle, we expect threaded couplings to remain stable/tight over time with no loosening, we expect that they can be taken apart when necessary, we expect that they do not generate noises due to micro-movements of the parts, we expect them not to develop corrosion.
Corrosion, that can be a big problem because it can seize or damage threads, it is frequent between different metals (titanium-aluminum,
steel-aluminum). In the past there were no alternatives and grease was used in the threads, to fulfill all four needs. But grease facilitates
loosening, does not last forever, migrates, changes characteristics, is washed away, does not always offer sufficient corrosion protection, and reduces noises only temporarily.
Thread-lockers have been used for many years in mechanics. What is a thread-locker?
It is a liquid that is applied on the threads during installation and solidifies in the following hours. It is available in many “strengths”, but for the bike it is preferable to use the weak one, Loctite® 222 or Arexons® System 52A22. Thread-lockers offer numerous benefits when used on threaded couplings: 1) prevent undesired loosening without the need to use high tightening torques, 2) prevent corrosion in the interface,
3) prevent any micro-movement with associated noises, 4) they remain stable over time.
Thread-lockers solidify when air is absent, therefore the entire space between the threads must be filled with product, otherwise, if not
enough product is used, it will remain liquid.
Using a thread-locker stronger than recommended can seize the threads, especially bigger diameter threads."
