# Loctite: where/when/which?



## pinkheadedbug (Aug 16, 2006)

Am just about to commence my first full build. Which nuts/bolts should I apply Loctite too, and at what point? Is there any use for red/green loctite in building a bike up or is it all blue?


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## ferday (Jan 15, 2004)

a) NEVER, EVER use any loctite other than blue.

b) i only use loctite after i've noticed a particular bolt (usually a pivot bolt) is coming loose. otherwise i use a bit of grease/anti-seize.


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## chucko58 (Aug 4, 2006)

I have a fair bit of experience with Loctite on automotive stuff. It's not magic. It won't save you from poor assembly technique or bad component design, but it can help stuff stay together. 

Loctite requires both parts to be free of grease - hit them with rubbing alcohol or automotive brake cleaner first.

Use Loctite blue (#242) on stuff you might want to disassemble later. Use red (#271) on stuff you won't want to take apart for a long while. Use green on parts that shouldn't ever come apart.

There is also a weaker Loctite yellow, but it's not very common.

I find the only place I would ever use Loctite on a hardtail is canti or V-brake studs. That might change if I ever get a FS bike. I use oil, grease, or anti-seize on most other bike fasteners.

IMHO Loctite isn't for spokes. If you find you need Loctite or "spoke prep" to keep your wheels from losing tension, you didn't put enough tension into them to start with.


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## hugh088 (Feb 1, 2004)

Red has it's places but they are few and far between. I have used it on parts that would be in the trash without it and saved money doing it. If you use it, the only way to get it apart is to use heat. This can be dangerous on aluminum bike parts. To do it I would use a high heat soldering iron and apply the tip to the head of the bolt until it hot. This will keep the heat concentrated in the bolt. When using any type of thread compound make sure the surfaces are clean and make sure you have some under the head of the bolt or the nut. These surfaces account for a lot of the torque in a bolt application.


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## bicyclehaven (Oct 11, 2006)

*identifying loctite*

You should always use the number to id a thread-locking compound. There are several blue loctites available, several reds, etc. You do not want to mistake one grade of loctite for another.
A good example, Loctite RC680 is green and is good for repairs in retaining bearings or press fit cups but if used on threads they are unlikely to ever come apart easily. Loctite 290 is also green but is designed for threads. It is similiar in strength to 242. It is a wicking compound and can be used when you don't know if any thread prep was applied and you don't have the time to diss-assemble the component.
To my mind the only reason not to use loctite 242 on a thread you haven't assembled yet is the cost. Those little bottles are expensive. 
Grease and adequate torque are all that is usually necesssary to keep things from coming apart


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## MikeDee (Nov 17, 2004)

chucko58 said:


> Loctite requires both parts to be free of grease - hit them with rubbing alcohol or automotive brake cleaner first.


Yes, I've heard/read that. The only problem is that the threads aren't protected from corrosion and torque values are almost always specified with lubricated threads (I don't think a drop of Loctite qualifies as adequate lubrication).


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## SteveUK (Apr 16, 2006)

Apparently, the Loctite website states that threads do not need to be completely free from grease, although the instructions on the bottles state otherwise. I usually apply a littl efresh grease to bolts and then wipe it off again, just enough to leave a thin coat. Too much and thread locks can be a little unpredictable.
I only use Loctite (243) on fork-crown bolts, rotor bolts, caliper bolts and stem bolts. Before I fit the rotor or caliper, I smear a thin layer of grease (Pedro's Syn) in the surface where the bolt head will rest, then apply the 243 to the end of the thread so that it gets distributed up the thread as the bolt is screwed in. On the caliper, I then run another smear of grease across the thread end of the bolt/caliper to seal it off, wiping away the excess grease. The procedure is more or less the same for my stem (Tioga Task Force) although I also run grease around the apertures that the bolts seat into. Once the excess is wiped away, the assembly is both sealed and locked. I have never had any problems with corrosion, parts working loose or, thankfully, creaks and cracks.
Peace,
Steve


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## the Inbred (Jan 13, 2004)

the only time i ever use loctite is when bolts come with it preapplied. otherwise, it never touches any of my bikes or components. Spoke Freeze doesn't touch my wheels, either.


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## jeffscott (May 10, 2006)

I have green locite in a red tube. 290 I use it on the rotor bolts and the bushing bolts and the chainring bolts.

Seems to work with greese on the bolts. Seems to come apart okay. Seems to stick okay.


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## KevinB (Oct 5, 2004)

I've occasionally had problems with loctite migrating to places where I don't want it. Not long ago, I started using Loctite 248. This is a medium strength threadlocker in stick form. It's handy for fasteners like pivot bolts where you want to get the threaded portion of the fastener past the bearing without allowing any of the threadlocker to migrate onto (and eventually into) the bearing.


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## skywaybuzz (Dec 31, 2003)

pinkheadedbug said:


> Am just about to commence my first full build. Which nuts/bolts should I apply Loctite too, and at what point? Is there any use for red/green loctite in building a bike up or is it all blue?


New forks, press fit steerers, press fit stanchions into the crowns, when new,290 Green Wicking Grade


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## Sorbut (Mar 7, 2006)

hugh088 said:


> Red has it's places but they are few and far between. I have used it on parts that would be in the trash without it and saved money doing it. If you use it, the only way to get it apart is to use heat. This can be dangerous on aluminum bike parts. To do it I would use a high heat soldering iron and apply the tip to the head of the bolt until it hot. This will keep the heat concentrated in the bolt. When using any type of thread compound make sure the surfaces are clean and make sure you have some under the head of the bolt or the nut. These surfaces account for a lot of the torque in a bolt application.


I do the same. Use whatever loctite I need based on application and how annoyed I am. Removal with heat works as Loctite is degraded by heat. On some a paint stripping gun is good but they do hit really high temperatures so take care. As above I try to heat only the bolt. I use a screwdriver, socket etc with heat directed onto the shaft of the tool applying undoing pressure. As a general rule try to avoid thread lock.


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## hugh088 (Feb 1, 2004)

For normal assembly you are better off with products like never-sieze thread compound or cr-40. It works much better then grease over the long term but does not stick as tightly as Loctite. That being said Loctite also makes a thread coupound that is aluminium based. I recently purchased some of this when I could not find never-sieze which is copper based in it's most comon type. When we speak of loctite we are usually refering to a type of glue. The thread coupounds are grease based with metal flakes and graphite suspended in it. What happens is that these flakes are compressed into layers and form a solid layer of flakes almost like a washer. Even if the grease is displaced by water this layer remains. When you remove the bolt the particles in the layer shear and the bolt comes out easily. I use this on just about every bolt on the bike except suspension pivot bolts which get blue loctite. Why loctite on the pivot bolts. These bolts connect two pieces of frame that rotate in opposite directions as the suspension works.. One direction they may try an tighten the other direction they try an loosen. If the bolts is made up correctly they should never get tighter, but while the same thing should be true for losening it sometimes happens. Hence glue the suckers with loctite.


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