The bottle cage bolts on my bike (carbon frame) tend to unscrew easily. Instead of tightening harder (I stopped at ~2Nm), which could damage the bosses in the frame, I am thinking of using threadlock on the bolts. It should be safe as the bosses are made of metal and it's not going directly on carbon. The question is: which threadlock is best suitable for this kind of job?

I have some blue one (Loctite 243), but if purple (Loctite 222) is better, I am willing to buy some.

  • Would you prefer another alternative, like a cork washer to take some preload? – Criggie Oct 22 '19 at 10:48
  • @Criggie on top of the threadlock? Or by itself? does it help? – Alessandro Cosentino Oct 23 '19 at 13:26
  • 1
    a cork or felt washer would sit around the bolt, not in contact with the thread, but binding on the underside of the cap and the top surface of your waterbottle cage. When squashed a bit, that would provide resistance to rotation. – Criggie Oct 23 '19 at 19:19

Loctite 243 seems like the best bet, but 222 could work.

From https://www.henkel-adhesives.com:

LOCTITE® 243 is a general purpose threadlocker of medium bond strength. This threadlocker secures and seal bolts, nuts and studs to prevent loosening due to vibration.

LOCTITE® 222 is a low-strength threadlocker that allows the adjustment of screws including countersunk head screws and set screws. Good on low-strength metals which could fracture during disassembly

| improve this answer | |
  • I am partial to the 222 as it is designed for small screws. It appears less likely to spin the threaded insert the carbon. – mikes Oct 21 '19 at 21:35

Blue should work just fine. It's probably overly strong for this application, so purple would be "better" here, but I've never had any difficulties unscrewing anything using blue Loctite.

| improve this answer | |
  • I guess my question boils down to this: if I use blue, will I be able to unscrew the bolts in the future without damaging the frame? I assume from your answer the answer is yes. – Alessandro Cosentino Oct 21 '19 at 17:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.