Loctite

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ossie
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Loctite

Postby ossie » 20 May 2013, 11:51am

Just built my tourer. On a previous occasion, whilst touring, a bolt holding one of my front pannier racks into the fork worked itself loose whilst heading down a very big hill to Perpignan. Needless to say I was slightly fortunate that the whole flapping mess didnt interfere with the the front spokes. Now this was probably my fault in not religiously checking every nut and bolt so will an application of Loctite prevent this sort of thing happening again and would anyone recommend using it ?

If so, how do you use it? Is it applied before hand to the thread or after things are tightened up ?

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Si
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Re: Loctite

Postby Si » 20 May 2013, 12:02pm

When I remember, I use threadlock...clean the threads and just whack a dab on the threads before doing up...instructions should be on the package.
iirc 'locktite' is a brand name that makes several different products...you could use their superglue (which is what many people mean when they say loctite) and that'll help, but you've always the risk of sticking yourself to your surroundings :oops:

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CREPELLO
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Re: Loctite

Postby CREPELLO » 20 May 2013, 12:14pm

You want to ask for Loctite 243 threadlock compound. This is suitable for small bolts, although I have used it on a bottom bracket, after checking with Loctite. Other formulas available are designed for larger fixings and shouldn't be used on smaller fixings.

It's a thin blue liquid you apply as you're mounting the bolt - just let it flow into the threads. Leave 24 hrs or so - it hardens by chemical reaction with the metal, so won't stick to paint.

ossie
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Re: Loctite

Postby ossie » 20 May 2013, 12:56pm

CREPELLO wrote:You want to ask for Loctite 243 threadlock compound. This is suitable for small bolts, although I have used it on a bottom bracket, after checking with Loctite. Other formulas available are designed for larger fixings and shouldn't be used on smaller fixings.

It's a thin blue liquid you apply as you're mounting the bolt - just let it flow into the threads. Leave 24 hrs or so - it hardens by chemical reaction with the metal, so won't stick to paint.


thats great many thanks, will give it a go.

stoobs
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Re: Loctite

Postby stoobs » 20 May 2013, 4:33pm

CREPELLO wrote:You want to ask for Loctite 243 threadlock compound. This is suitable for small bolts, although I have used it on a bottom bracket, after checking with Loctite. Other formulas available are designed for larger fixings and shouldn't be used on smaller fixings.

It's a thin blue liquid you apply as you're mounting the bolt - just let it flow into the threads. Leave 24 hrs or so - it hardens by chemical reaction with the metal, so won't stick to paint.


Actually, technically speaking, the liquid threadlockers are anaerobic adhesives, which do not cure in air, but do cure in the absence of air, such as in the restricted areas of threads.

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Redvee
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Re: Loctite

Postby Redvee » 21 May 2013, 12:03am

I bought a stick of blue Loctite from the orange car accessories shop and it's like a lipstick in that you twist the base to get more out but I just put the bolt into the stick and give it a twist.

Brucey
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Re: Loctite

Postby Brucey » 21 May 2013, 2:05am

there are many, many different grades of Loctite and similar products; they are all slightly different. But widely available blue coloured loctite is usually a non-permanent compound. If you really want to stop the bolts from turning (but still be able to remove them using normal hand tools) there are other loctite grades that give a stronger bond.

For carriers, where possible my preferred approach is to put a bolt through from the inside of the dropout or bracket, then use a nyloc nut on the outside.

In any event a loose carrier should rattle like fury and this should tip you off that there is something amiss, hopefully before the fastener backs out all the way. With nylocs, it can take thousands of miles for a nut to back out appreciably on a bicycle, even if it isn't at all tight. Bhy contrast a standard bolt can be lost in a couple of miles.

Note that carrier bolts see bending loads; these impose different (higher) stresses on the bolts which do tend to loosen them.

cheers
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pioneer
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Re: Loctite

Postby pioneer » 21 May 2013, 7:50am

I asked my daugher to get some Loctite blue' (threadlock) from Halfords the other day and they'd sold out. (Did buy one a few months ago, but cannot find it anywhere. I expect it'll surface when I'm looking for something else next week!). But she found another make that was/is cheaper. Probably very similar anyway. But I only use it on chainring bolts.It works a treat too.

Brucey
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Re: Loctite

Postby Brucey » 21 May 2013, 10:56am

re using loctite on chainring bolts;

I don't advocate this; the reason is that the bolts need to be properly tight in order for the chainring interface to work properly. Arguably the main benefit of loctite is that slightly loose fasteners don't back out and get lost.

IME this isn't really necessary with most chainring bolts; if the bolts are not tight enough, the noises that are generated will soon tell you that there is something amiss.

If you retighten chainring bolts (which is a good idea after a few hundred miles) and they have loctite on which has even partly cured, the sleeve part of the bolt will try and turn, and any torque setting you use will be 'wrong'. If you use non-hardening threadlock, you won't easily loose a loose bolt, but you weren't going to do that anyway, were you...?

For chainring bolts, I prefer to test that the bolt halves will thread all the way into one another without any binding, then add a little copper ease to the threads (but not the outside of the sleeve) and tighten to the correct torque setting. Clean threads, correct lubrication, and the fine thread pitch ensure that the sleeve almost invariably doesn't need to be held during tightening, (or disassembly, any time in the frst five years or so).

Undoing chainring bolts with loctite on is one of my least favourite ways of spending time; the unnecessarily binding sleeves drive me nuts.

cheers
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pioneer
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Re: Loctite

Postby pioneer » 21 May 2013, 11:15am

As most of my riding is fixed' and they take a real hammering, I disagree. By experience, I can tell you that it's the only way I've found to keep the little blighters good and tight.

Brucey
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Re: Loctite

Postby Brucey » 21 May 2013, 11:38am

I have also ridden fixed for many thousands of miles, ridden hillclimbs etc. It doesn't get much harder on the chainring bolts than that, even on a 144BCD setup.

It has been my observation that chainring bolts often 'loosen' because of settling in the joint, fretting etc. It is very rare for the bolt to actually back out unless the joint was already either loose or at least not tight enough, anyway.

I guess if the BCD is smaller, and/or the sleeves don't fit the holes in the chainring very well, stuff can move round differently maybe.

If there is lubricant on the chainring where it bears against the spider, the parts are badly made (clamping faces not flat) or the bolts are not tight enough (what torque setting do you use?) then the joint can move and the bolts will eventually back out. But in this case loctiting them cures the symptom, not the cause, and the chainring will likely still be moving around. In this case every time you take the chainring off, the interface is typically full of black crud which is wear debris from fretting.

I'd be interested to hear if others also loctite chainring bolts, and how they get on when the time comes to take them apart. In a lifetime of cycling and working on bikes, it has never occurred to me that it might be a good idea; I've had a few cases where cheap parts that don't fit right have loosened in the first few hundred miles due to settling, but other than that, no slackening/backing out troubles.

cheers
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Colin Jenkins
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Re: Loctite

Postby Colin Jenkins » 21 May 2013, 2:39pm

Hello Ossie.

I don't use Loctite anywhere on a bike!

Pannier frames, carriers, mudguards etc. are best secured with Nyloc nuts and bolts. Where the frame has mudguard eyelets, fix the bolts securely into these then hold it there tight and put a Nyloc nut on the back to lock it. They won't loosen under vibration, but can easily be dismantled again with ordinary tools. I even lightly grease them to prevent corrosion and seizure, and they still never come adrift. As per Brucey's reply further up.

Regards,


Colin Jenkins.

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CREPELLO
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Re: Loctite

Postby CREPELLO » 21 May 2013, 5:08pm

Colin Jenkins wrote:Hello Ossie.

I don't use Loctite anywhere on a bike!

Pannier frames, carriers, mudguards etc. are best secured with Nyloc nuts and bolts.
Nylocs are fine where you can fit them, but what about bottle cage mounts or pannier mounts at dropouts where the cassette/chain come very close to the mounts? Some mudguard mounts are also blanked off at the back. Nyloc nuts on handlebar stems? :?

How much of an issue are bolts coming loose, generally speaking? Do we always threadlock various brake bolts, seat clamp bolts etc? I don't. I apply the appropriate amount of torque.

Brucey
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Re: Loctite

Postby Brucey » 21 May 2013, 6:39pm

quite a few bolts come fitted with blue non-hardening threadlock when new; top cap, brake bolts, pinch bolts, canti stud bolts... etc etc...

cheers
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CREPELLO
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Re: Loctite

Postby CREPELLO » 21 May 2013, 8:08pm

Brucey wrote:quite a few bolts come fitted with blue non-hardening threadlock when new; top cap, brake bolts, pinch bolts, canti stud bolts... etc etc...

cheers
Quite a few don't bolts don't as well. Mudguard screws, stem clamp bolts, seat clamp bolt etc. Just trying to work out the necessity of applying the threadlock compound. Or why some bolts come equipped with TL and others don't?