Wattsup

I have Shimano XT brakes, and I see that the bolts have thread locker on them when I removed them to clean on my titanium frame and carb fork. . I've always followed advice and greased all parts that thread into the frame in order to prevent galvanic corrosion and seizing, but I don't think threadlock and grease are compatible. What are the best practices for brake fixing bolts in this situation? I definitely wouldn't want brake bolts to seize in my carbon fork or titanium frame, and by the same token, I wouldn't want them working their way out. What about light grease and frequent checking of the tightness? Shimano also recommends a bolt cap or wiring, but my brakes had neither.

CliffordK

I've used purple loctite which is very low strength during assembly.

I haven't thought about brake fixing bolts, as you apply the goo to the threads, but the corrosion risk is with the frame.

Wattsup

Yes, I understand that. So what about the risk of corrosion though?

Bike Gremlin

I've never had problems with bolts coming out when using anti-seize paste (more durable anti-seize protection compared to grease). For brake bolts - often without bothering to thoroughly clean the residue of the dry thread locker that is usually placed on them. No loosening, no seizing up problems whatsoever.

Of course, a safe bet in terms of preventing any loosening would be using some blue, or purple (even weaker) Loctite (the lower-powered ones, that don't require heating up in order to remove bolts, but still keep them in place).

I'm not a fan of thread lockers and don't use them unless I see there is a problem with stuff getting loose instead of being torqued properly.

KerryIrons

I've applied plain grease over thread locker compounds many times with no issues. While anti-seize is typically more long-lasting than grease, that is only an issue if you are not planning to re-grease for a LONG time. Grease works fine.

ClydeClydeson

I always used grease on things bolted to my Ti frame and never had an issue with seizing or corrosion. I did fairly frequent (~yearly) teardown and rebuilds, though, and seldom/never rode it in winter where the salty slush would seep in and act as an electrolyte.

Rdmonster69

I believe copper based anti seize is the thread lube of choice for Ti frame applications and is what I chose for my Litespeed build. Frequent checking is advised but if properly torqued I wouldn't be super concerned. That being said I am extremely fastidious with my bikes and am constantly cleaning and checking things.

Thread lockers are fine but I have seen galvanic corrosion on portions of bolts that were not coated. These are in motorcycle applications which see far greater extremes of heat and vibration as well as much longer times between disassembly but it is worth noting.

A perfect example is the belt covers on my Ducati. Steel bolts into an aluminum cylinder and head. I use only a small amount of thread locker to avoid headaches... the uncoated sections have small amounts of corrosion. Easily fixed with a wire brush and chasing the threads but I just used anti seize and torqued an checked on my last service. Botls were fines this time.

sch

FWIW I have had 3 Ti frames: now retired Teledyne Titan ( ~15k miles), a Rotator recumbent now at 36k miles
and a Lightspeed, now at 32k miles. Never had any problems with corrosion or binding of bolts, BB or seat post.
The Teledyne was built in 1976 and hung up when life got busy in 1981 in the basement. I rebuilt it in ~'99
and the seat post slid right out when the locking collar was loosened. Just used lubriplate. As to thread locker,
if the manufacturer puts thread locker on the screws, then I clean them up a bit and put more on on re-install.
Probably not a good idea on BB threads but they are supposed to be greased or anti-seized, not thread locked.

CliffordK

The obvious choice for a Titanium bike would be:

Titanium Brake Nuts from Toronto Cycles

Big red notice saying they put their online store on hold a year ago.

They also had the titanium brake center pivot bolts for certain brake models.

You can still get Titanium brake nuts from EBay, but I don't see the pivot bolts (unless you can find a brake model that came with them standard).

CliffordK

I still like my low strength purple thread lock. Especially on things like Italian bottom brackets.

KerryIrons

When I got my Litespeed back in 1998, I asked Litespeed what to use. They said grease. I put over 160,000 miles on that bike (not counting roller miles in the winter) and never had a single issue. Same story with my Lynskey now. You only need anti-seize when you plan to leave things for a long time and not do regular maintenance. Or maybe when you ride in a lot of salty environments.

Wattsup

Yes. Someone here on these forums made the comment, it's not the kind of soap one uses but rather the frequency that's important. Just regrease periodically. But....my question had to do with brake fixing bolts. Why are we not concerned that they will corrode right into the titanium frame?

Andrew R Stewart 

That's me. But my stating this (and I have so many times here and at work) usually references the people around you being glad that you use some sort of soap frequently Like them, we here don't so much care that a specific lube or compound is used but that one is used and the bike gets routine attention. Andy

HillRider

I have three Litespeed Ti frames, one 1996 (85,000 miles), one 2005 (58,000 miles)and one 2006 (54,000 mil;es) and all three have carbon forks with recessed brake mounting nuts. I have never used grease, anti-seize on threadlocker on the bodies of brake fixing bolts, only grease on the threads, and they have never shown corrosion or any damage when removed for semi-annual routine maintenance. I do use grease on the seatposts and most other threaded fasteners and anti-seize on the bottom bracket cups but the brake bolts get little attention and don't seem to need it.

Rdmonster69

Interesting!! .... Im trying to remember if my Chris King BB recommended anti seize and I think it did. Not sure though.... For my recent rebuilds I simply greased the BB on my other bikes. Working on motorcycles has made me a slave to service manuals. Different loctites, anti seize and lubes. To me anti seize is like fancy grease lol.

Ironfish653

How much time is your bicycle spending subsea? The way you guys talk about corrosion, it seems like your bikes spend more time underwater than my ROV.

If you’re using a passivated stainless steel bolt , then it should take a long time before corrosion should become a factor. Any barrier material in the threads, whether it’s threadlock, antiseize, PTFE paste, or even grease will only extend that time.
What you use will depend on how much torque the fasteners require, how much vibration it sees, an how often/ easily it’s required to be removed.

Wattsup

I use grease on the brake fixing bolts too. It seems though that Shimano and others recommend threadlocker on those threads. That's the whole point of my post....best practices for brake fixing bolts threading into a titanium frame.

Ironfish653

I missed the Deore XT in the OP; these are canti's or V-brakes, yes? You're talking about the M6 bolts that secure the brake arm on to the pivot post? Those usually come with a 'patch' of threadlocker already applied; a dab of plain, blue, Medium LocTite will be sufficient to keep the bolts from working loose under the twisting and pulling forces they may be subject to.

You're hung up on the wrong aspect of titanium. Ti is more corrosion resistant than stainless steel, and far less reactive than Aluminum. In a mixed-metal, galvanic environment, the Aluminum will be affected first, and far, far faster than SS or Ti.
What you need to watch out for is that Ti fasteners or threads cut into a Ti part will deform or break much more easily than steel fasteners. Do Not over-torque Ti fasteners, or steel fasteners into Ti.
If you're concerned about the part loosening up, use your thread locking compound.

Wattsup

No, they're disk brakes. As for the corrosion, I 'm not concerned about the titanium per se. It's the less noble metal that will corrode, the threaded bolt, possibly damaging the threads of the titanium. I often ride in soupy, muddy condition. Anyway...I've decided on a course of action. I'll grease (or use copper antiseize ) those bolts every other bolt. I'll check them often to be sure they haven't loosened, and I'll apply lock caps to prevent the worst case scenario.

Ironfish653

Unless you leave your bike underwater for longer than this thing; you’re worrying far too much about something that has little likelihood of happening the way you imagine it will.
SS and Ti is pretty stable, Aluminum and Ti isn’t bad, but Aluminum and SS is pretty reactive, to the detriment of the aluminum.
We use Ti and SS for the really high-tolerance precision stuff, Aluminum for where we can keep an eye on it.
So, unless your bike spends weeks at a time, surrounded by seawater at 3000psi, carrying around a 6400 VAC, 250 hp electro-hydraulic control systems, your fears of rampant, rapid, galvanic corrosion are a little unfounded, IMHO,

Rdmonster69

That's super cool. I am not too concerned about anything on my Ti bike developing corrosion. I just (seem) to remember the install instructions on my BB stating to use anti seize. Most likely because they do not know what type of metal it is going in. My Ti bottle bolts got a dab of Loctite blue and gently tightened. I've used a fair amount of Ti fasteners on RC cars and motorcycles. You def. have to be careful there.