IPassGas

After removing/cleaning rear disc caliper, I added a bit of blue loctite to mounting threads. Bad idea?

Over time, most everything on my bikes is, at various times, removed, cleaned and greased. Loctite can make parts difficult to remove, possibly striping hex heads. So I don't use it except on some things like brake mountings. Is the blue stuff a bad idea in general on any bike bolts? Rather, I should instead just set the bolts properly tight and check stuff now and then for looseness.

jadmt

blue loctite is great as it also acts as a anti-seize agent making it possible to remove bolts that would otherwise corrode especially on two dis-similar metals. Blue loctite does not make it impossible to remove without heat like red loctite does.

Iride01 

I've never used loctite or any thread locker on a bike. If it's already pre-installed on a bolt or screw of something new you are putting on, then by all means use that. If you have something that keeps getting loose after being properly tightened, then sure, give thread locker a try.

Most screws and nuts have been staying on securely without thread lockers for a very long time.

afm199

I use only blue and only on bolts where is was used as a preinstall method. There are only a few of those.

blinky

The only Loctite product that I've used is Loctite 660 - used it a few years back to solve a creaking issue at the BB when honking up gradual grades - put a small amount on each surface of a Chorus tapered BB bearing where the cups slide on , letting it cure overnight - was at the recommendation of a friend and great bike mechanic - worked wonders and solved the issue - personally wouldn't mess with Loctite willy nilly .

byscott

I can’t see that much downside to using blue Loctite on many fasteners — stem, seatpost, brake mounts, etc. I’m not sure it’s necessary for most of those fasteners, assuming that they have been properly torqued, but by the same token I can’t see any harm, either.

Where would I insist on it? Rotor bolts, chainring bolts, and crank arm pinch bolts are a few places that come to mind.

Dan Burkhart 

For anyone planning to buy blue Loctite I recommend 243 rather than 242. Same strength but it will tolerate a bit of oil or grease on the thread

rm -rf

I don't know rotors. The two crank arm pinch bolts need grease and a torque wrench. Then they won't get loose. Grease and torque on the stem bolts. I've never needed to do chainring bolts, but grease sounds correct there too.

I do use loctite on bottle cage bolts and on blinky light clamps. I don't want to tighten those too much, and the thread locker is good there.
Loctite on my adventure bike's fender and rear rack bolts.

2_i 

Use only an amount that will spread over several threads. If you flood a long thin bolt, you may have serious problems unscrewing that bolt without damage even when you use the blue Loctite. there is also a fallback option of purple Loctite, with a still weaker holding power than the blue.

byscott

No argument there, I guess. The bottom line is probably that properly torqued fasteners are unlikely to come loose, though I do notice that I’ve received several rotor bolts with thread lock pre-applied. I think I had some FSA pinch bolts with thread lock pre-applied also, though I could be mistaken.

I’ve always assumed that many fasteners will need some sort of compound or lubricant — grease, anti-seize, or thread lock — as a consequence of being inserted into a dissimilar material. It’s usually a steel fastener in an aluminum part. That takes us to the “grease vs anti-seize” discussion, which I think has been beaten to death in several other threads ;-)

FWIW, I would never argue with someone who uses “rm -rf” as a handle <g>.

*Scuba 

I will use blue medium strength thread locker on canti or v-brake mounting bolts. The canti brake studs get a very thin film of grease to prevent corrosion. Also use the same medium strength thread locker for disc brake caliper mounting bolts and the rotor bolts, just as a preventive for stuff to vibrate loose and act as a barrier against metal on metal contact.

easyupbug 

Touch the head of a screw/bolt with a soldering iron and blue loctite will release easily, commonly done on small screws in firearms. Even with proper torquing for safety I use blue on my daughters and granddaughters bikes stems and crank bolts.

3alarmer 

.
...on a bicycle, I think I only use blue Loctite on fixed BB cups that are RH threaded (Italian, French). But I use it routinely on those.

zandoval 

Things I have successfully used instead of Loctite: Elmers, FIngernail Pollish, Linseed Oil, Pipetite-Stik pipe thread sealer

Just remember that your not supposed to cover the entire length of the bolt.

Camilo

I used blue locktite on my one and only Italian bottom bracket. It works. Theoretically not needed with proper torquing, but the first time I installed it, it worked loose and I didn't want to mess with it, so the locktite.

Nofiltercycling

If at all

on things that keep coming loose after torquing to spec

or if something small is stripped
and there is no room to use a larger bolt a little would help there too

thats about it

pdlamb

Most bolts just get grease. I'll use Loctite on rack mounting bolts and perhaps water bottle cage bolts. I've seen Loctite on new clipless cleats, but if I have to remove or replace those bolts they're probably near end of life, so I'll grease them and hope I can get them out when the cleat dies. I think I've seen Loctite on some new threadless stem bolts, but again, they'll get grease from me on a re-install.

icemilkcoffee 

So given the hear of the disc rotor, would the rotor bolts self-release?

easyupbug 

For lead based solder you need to get to 700ºF and irons will do that. Rotor temps vary a lot with disc size and use but on serious downhill mtb runs I have heard of over 200ºF. I believe cars/trucks can go twice that and in Nascar runs at night the rotors can glow red which means Blue would be long gone.

Reynolds 531 

A trick is to heat any fastener until you smell Loctite, and remove heat. It can only be a second or two.

But its me 

I find the blue Loctite 248, the stuff that comes in a stick form, to last longer in storage than the liquid version. Easier to apply too.

2_i 

You can typically dilute liquid Loctite with acetone. It is usually superglue with some additives.

But its me 

I found it thinned with age, oddly enough. Always wondered if it picked up contamination from the applicator tip, such as grease. Either way, the stick is the only stuff I use now.

2_i 

I have the stick version for one of them, maybe red. Following this discussion I will try it when an occasion occurs. One benefit for the liquid ones, I found, is that you can buy them in large containers and pour into small for the road. Sometimes I am stuck at remote locations without much infrastructure and small quantities of Loctite go into my toolbox.

easyupbug 

Red Loctite 262, 263 & 271 and the Red 268 stick are for essentially permanent assembly. I am hyper cautious with the front end of the kids bikes but think these are way over the top. If you like the stick I would go with the medium blue 248 at the most or any of the blue liquids, they will do the job and disassembly will not be an issue.