what needs grease/lube/anti-seize/loctite?
 

i'm going to be putting together a fixed-gear bike soon for the first time, and i want to make sure i do it right... in particular, i don't want anything falling off unexpectedly, or getting stuck when i want to change it.

so, what do you recommend i use, if anything, on:

the rear cog?
the lockring?
the bottom bracket?
the crankset bolts?
the chainring bolts?
the wheel axle bolts?
the chain?

You can use grease just about anywhere you would use anti-seize, it helps you torque more accurately, too. I use anti-seize because I already have it. If I didn't, I'd grease.
r/c & l/r: anti seize. If you were using a suicide hub you'd want to loctite the rear cog
bb: anti seize if english, if Italian use loctite on the right (drive) side cup
crank b: anti-seize
c/r b: anti-seize
axle nuts: anti-seize
chain: no grease - oil, buy some specially made chain oil (I like the dry stuff), soak the chain overnight, wipe off the excess, and install.

Nothing needs loctite and anything with threads needs grease. It never hurts to have a swipe of an oil rag over any other metal to metal interfaces. Make sure to grease the stem if it is a threaded stem and also the seatpost. And oil the chain.

cool, thanks for the answers!

when i bought my last cog the shop mechanic told me to grease the cog, use blue loctite on the lockring. that's worked great so far. if you're running a suicide cog, no amount of loctite or extra BB lockrings will hold it on securely if you are putting lots of backpresure on it. it may hold for a long time but it can still slip. I've done it.

use grease on just about anything else that screws together, and any other metal-metal contacting parts (seatpost, stem).

Grease does not equal anti-seize compound. In fact, greasing a threaded fastener will likely alter the torque reading when you use a torque wrench, most often resulting in overtorquing. The only exception would be for soft metals like aluminum, which has a tendency to gall when overtorqued dry. Because Al is extensively used on bicycles, that is why it's common to recommend greasing the threads to prevent galling. Still, anti-seize compound is widely available and far preferable.

Now it is true that modern grease formulations can be more sophisticated than the old days when grease is nothing more than oil mixed with soap. But their primary function is still to lubricate. The better it does that, the worse it is for threaded connection, which counts on preloading (elongating) the bolt for rentension. Adding a lubicant in the mating surfaces increases the chances of that preload loosing hold.

Here are some very generalized guidelines:

1. Anti-seize: all threaded connections that have mechanical locking means (lock washers, etc.) and/or have long enough mating section to develop a proper preload tension. Plus, most mating surfaces of soft or dissimilar metals.

2. Grease: (typically encased) moving contact surfaces that require friction reduction (BB, headset, brake cables, etc.)

3. Loctite (chemical threadlocker): threaded fasteners that are:
a. subjected to shock & vibration and/or assembly designed to move after been assembled (e.g. frame mounted brake caliper)
b. too small (or mating section too shallow) to apply sufficient preload tension (e.g. RD pulley screws)
c. These are actually easy to identify because most come from the factory with some blue, white, or red thread locker compound already applied on the threads.

I disagree. "Almost" nothing needs locktite. One thing I locktite on my mountain bike is the bolts that hold the brake lever and shifter clamping assembles to the handlebars. This allows you to keep the clamping bolts a little loose so the levers and shifter assemble will spin on the handlebar if/when you crash. This can prevent levers and more expensive parts from breaking in a crash. If you don't use locktite the bolts will continue to loosen until your levers won't hold position.

grease does not equal anti-sieze, but I think it's important to note that grease is a hell of a lot better than nothing for this application. the point here is that there is some layer of something between the two metal surfaces so they do not start bonding to each other and seize up the bolt or whatever. anti-sieze is obviously the correct thing to use here because it was designed for that, but a hell of a lot of people use grease and have for a long time. if you are concerned enough about precision to be using a torque wrench it may make a difference, but i'm willing to bet the majority of the people here working on bikes don't even own one.

I use torque wrenches where necessary, and I use grease/oil/anti-seize where appropriate without adjusting the torque settings. Torque is almost never specified "dry"; the default is for 30W motor oil. If you're worried about it, then set the wrench for the low end of the range when using oil or grease.

Also, for using anti-seize instead of oil, the materials are much important that the location. Titanium for instance should always use (nickel) anti-seize. Aluminum usually (copper) anti-seize.

Torque specs are definitely for dry contact, without any friction modifiers in the threads. That is the only way for the fastering torque to track preload tension (or more directly, bolt elongation) correctly. The moment you introduce oils, grease or any other friction modifiers in the threads, that torque vs. preload curve is no longer linear. So even if you "derate" the spec'd torque using grease or oil, it's difficult to hit the spec'd preload tension just right.

There is another reason not to use grease. Again, grease is mostly oil thickened up with soap or some alkyline compound like lime (not a chemist). Problem is, over time, that oil might dry out, and you end up with a residue that don't offer much galling protection.

Anti-seize compound OTOH use metal compounds that are designed to offer a barrier layer even when all the oils have disappeared, particularly for high temp applications. The choice of different anti-seize compounds have more to do with that temp rating than the particular type of metal alloys. Nickel-based anti-seize is rated at much higher temp than copper-based. Since Titanium fasteners are most commonly selected in extremely high temp applications, that is why nickel anti-seize is often used in concert with Ti.

As I said in my earlier post, I agree with you and chunts that, with aluminum, using grease is better than not using anything at all. Most people tend to over torque, so given that situation where preload tension is not gonna be in spec anyhow, it's better to prevent galling.

It's the lesser of two evils.

Since the OP is asking to "make sure he does it right". I would strongly recommend anti-seize and a torque wrench.

Two good links on the subject:

http://www.parktool.com/repair/readhowto.asp?id=89

http://www.parktool.com/repair/readhowto.asp?id=88

Very few threads are really "dry". There's machining oils and preservatives on all of them (except very old ones where it's worn off or evaporated) whether you add it or not.

The "30W default" is for automotive assembly where the ambient oils have been removed by (e.g.) parts washing fluids. Bicycle practice might be different, but it hardly matters given the wide range of most torque specs.

I've been in the automotive industry for 35 years and unless otherwise noted by the manufacture we never oil threads to torque them.

Our rule on the race cars is no dry threads, ever. All threaded fasteners get anti-seize or motor oil, depending on the application. Always anti-seize on dissimilar metals, aluminum, titanium and magnesium (under washers here, too). Just a drop is enough. Makes disassembly soooooo much easier.

Dave.

It would be easy to argue with a lot of what's already been posted, but I'm just going to address titanium frames. Anything threaded into these frames needs anti-seize. This includes BBs, derailleur hanger bolts, bottle cage bolts, fender stay bolts - whatever. I've had bottle cage bolts gall almost immediately on me.

If you don't have anti-seize (I like the copper based stuff the best), then use grease. A lot of the silver stuff is lead based and should be avoided. It gets all over your fingers and guess where it goes next. If you do use this stuff, use rubber gloves and make sure and immediately wash off anything that gets on your skin.

I always use Loctite on Italian- and French-threaded fixed cups, which are inherently self-loosening, i.e., they have a nasty habit of coming "un-fixed" under load. Anti-seize works great on properly-engineered bottom brackets (English and Swiss).

I've worked on cars, motorcycles, and bicycles for good part of the past 25 yrs, besides being a degreed and practicing ME. Anti-seize is far and above the preferred thread protectant, for many reasons:

1. Proper torque & preload tension
2. High temp seize-up prevention
3. Galvanice reaction prevention (dissimilar metals)
4. Oxidation/corrosion prevention
5. Thread lubrication (for difficult to turn bolts)
6. Thread sealant (water ingress protection only)

Only anti-seize can do all this.

Grease makes an adequate substitute in some applications. I would never use motor oil. I've been around some master auto mechanics that would make me eat a grease burger (um, that's automotive grease) if I assemble torque sensitive parts (wheel lugnuts, cyl hd bolts, etc.) with motor oil on the threads.

Here's the reason:

Upon initial assembly, the long chain molecules (mineral oil, olefins, or synthetic ester-based polymers) in the trapped oil will resist the shearing force acted upon by of the counter-rotating thread contact surfaces. This is essentially dynamic thin-film lubrication - precisely what motor oils are designed for.

Problem #1: Motor oil is so excellent at thin film lubrication that the fastener will be over torqued.

Problem #2 Once the applied torque stops, what was dynamic is now static. The motor oil will eventually thin out between the contact surfaces completely over time. Heat, if present, will accelerate this process. Because motor oil has virtually no solids content, metal to metal contact will eventually result. This leads to two negative consequence:

a. Galvanic reaction may occur.
b. The now "dry" threads, being originally over-torqued, will now take much more force to "break" loose.

Bike fasteners are typically light-duty, small size, and low-torque. And usually not subject to high temp, so you might get away with oiling the threads. I personally would not allow anyone I have influence over to use it.

Sorry for the long diatribe. Just trying to clear some misconceptions.

The common practice is to use a lock ring on the left side. Even so, the lock ring sometimes still comes loose. It's not a bad practice to loctite the lock ring ONLY, and anti-seize the BB threads inside the frame.

I should qualify that statement, we never put “oil” on the threads. If we put anything on the threads we use anti-seize or a thread locker. The only threads we always lube are the stainless steel fittings we use on compressed natural gas vehicle and compressor stations. Stainless to stainless fittings gald when put together. We use nickel impregnated Teflon tape or liquid Teflon with nickel. The nickel acts as a lube to allow proper setting of the threads.

Bolts for rack/fender mounts.

1) Lockrings for track cogs don't need loctite, because they have opposite threading, right?

2) What's galling?

1.Not familiar with track cogs, but if it is anything like the outermost threaded cog in a regular cassette, it is because the right-hand thread naturally gets tightened by the chain when driven.

2. Galling occurs when two metals in moving contact at high pressure "weld" to each other at certain spots and then tear small chucks of material from each other.

I agree. I've had bolts holding my rack on work loose. It's a major pain when you're out in the middle of nowhere with a load on your rack. I always install those bolts with Loctite. In addition, I always carry an extra bolt or two, and I also carry Loctite.

That would be the "proper way". In reality no one is using torque wrenches to put on every bolt and nut, unless some sort of carbon part is involved. A torque wrench isn't even necessary for the majority of the stuff you do on a bike.