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I understand that a good grease for bike bolts is the Parktool grease.

The "gel squeeze threadlocker blue" pictured below is sold at my corner hardware store for curbside pick-up. Will this do to lock water out from pedals and shoe bolts? During this lockdown, I'm weary of placing yet another online order (and likely someone is worn out of packing and mailing).

Since grease inevitably stays in small amounts on one's fingers, not just on the bike's components, if you are in California and can confirm that this product manages to escape California's Proposition 65 warning, please do.

Permatex

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    Hello and welcome to the site! Make sure to NOT confuse threadlocker with grease, their purpose and applications on the bike are very different. Many people learned it the hard way after trying to unscrew a bottom bracket or pedals installed using threadlocker insstead of a grease. Commented Apr 9, 2020 at 18:44
  • @GrigoryRechistov If the two parts move with respect to one another (bottom bracket, handlebar) ==> use grease, never threadlocker. If the two parts do not move (all bolts, pedals) ==> use threadlocker, but grease will also be fine. Do these two statements summarize it?
    – Sam7919
    Commented Apr 9, 2020 at 18:47
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    I personally use a copper-based assembly compound on every bolt that I will want to undo again in the future. The only time I use threadlocker is when the bolt has already exhibited an inability to hold its position due to vibrations etc - specifically the front derailleur braze-on mount bolt. Bearings get grease of course.
    – Criggie
    Commented Apr 10, 2020 at 0:09
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    @GrigoryRechistov Ah, I think I see where I was confused. I expected "threadlocker" types 1- to keep the threads where they are, as long as there is no torque, 2- not allow me to over-torque, as grease would, 3- give in and break after a small tug if/when I need to change something. From your comment I see that (3) may be entirely wrong. The two parts may well become near-fused.
    – Sam7919
    Commented Apr 11, 2020 at 13:01
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    @Sam, well, as I understand it, (1) is indeed the purpose of threadlocker, but additionally to prevent unscrewing under vibration, i.e. varying load/torque. Regular dry friction does the same job, only that it is weaker. There is no protection against (2), i.e. if a user goes nuts on a bolt, the threads will become stripped. (3) is also true for the types of threadlocker used on bicycles, but "a small tug" may become quite hard one if threadlocker is used where it is not supposed to be used, or a wrong type of the stuff is used. Commented Apr 11, 2020 at 15:47

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"I understand that the "perfect" grease for bike bolts is the Parktool grease." Parktool has a great reputation (and often a premium price) but it has no patent that would make every product they make The Best Thing(TM).

There are many good greases for many various manufacturers. There is not much to make wrong with a traditional grease (petroleum jelly), just choose the right viscosity. There are many modern greases with various additives (teflon, ceramic) from many manufacturers.

The main point of a grease is to maintain the surfaces easily separated, screwing and unscrewing possible, prevent rust and bonding of those surfaces. A thread-locker, on the other way mainly joins those surface and will enable firm connection with a smaller torque.

But also, some threads are to be greased and some are to be thread-locked. The manufacturers normally say which is supposed to be used. For example, pedal threads are normally greased, while stem and handlebar bolts are usually thread-locked. Also, bolts on derailleurs are usually thread-locked. Carbon on carbon in seat-tubes usually calls for carbon-paste while metal-on metal seat-tubes normally call for a grease. For shoe cleats you should read the recommendation of your manufacturer. Mine calls for a grease but I would expect a thread-locker to work fine too.

You should use what the manufacturer calls for especially when you are screwing to a certain torque setting. One could over torque the threads when greasing what was supposed to be thread-locked. Or the opposite.

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    I use "marine grease" on any bearing in my bikes - sometimes branded as trailer grease, because it resists being washed out, and has a resistance to salts.
    – Criggie
    Commented Apr 10, 2020 at 0:10
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Park Tool does not make grease. They buy from someone, probably Mobil, then rebrand it.

NLGI-2 grade marine grease is a good, general purpose grease for bikes, like Mobil SHP 222. For the price of Park Tool, Shimano, Sram or any other "magic" grease, you can buy off-the-shelf, half a kilo of great marine grease like SHP 222 and a nice grease gun. This will probably outlast the bike, you and few generations.

However, grease is not something that will stop galvanic corrosion, that is, steel "welding" to aluminium. The most effective compound to buy off-the-shelf is, copper grease. There are fancier montage pastes from manufacturers like Molykote, which are crazy expensive.

I use copper grease on bikes, cars and almost on every equipment I own, with huge success.

Still, it's a best bet to at remove seatposts, pedals, etc and re-grease them. Grease is much better then having nothing. Copper grease is much, much better.

A light threadlocker, not medium or high, when applied correctly, will also help SLOW galvanic corrosion due to no water ingress (electrolyte, in this case). It's much more expensive, shelf life is very limited, and not effective as copper grease, though.

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  • Neat. I'm just becoming aware of "copper grease". Question: How do you apply it to, say, the pedal-to-crank connection? Is there a "grease gun" for the particular tub in which copper grease is sold? I'm hoping to avoid the "pick a bit with a random wooden stick and gently slather it" approach.
    – Sam7919
    Commented Dec 6, 2022 at 21:15
  • remove your pedal, rub it to threads, thread back on... Commented Dec 6, 2022 at 21:29

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