Hot take: I thought greasing pedal threads was a myth until I stripped one

Look, I’ve been wrenching on my own bike for about 3 years now and I always figured grease on pedal threads was just something the fancy folks did to feel important. My old hybrid had the pedals on dry for two seasons and they came off fine with a basic wrench. But last month I swapped pedals on my mountain bike after a muddy ride and the right one locked up so bad I chewed the threads trying to get it loose. Took me 45 minutes with a breaker bar and some PB Blaster to finally get it off, and the crank arm threads looked rough after. My buddy at the local shop in Portland said a dab of grease would have stopped that from ever happening because it keeps corrosion from welding the metal together. Now I keep a little tub of Park Tool grease in my bag and hit every pedal thread before screwing them in. Has anyone else had a crank arm ruined by skipping this step?

2 comments

2 Comments

thomas.piper1mo ago

Man, I feel your pain! I read somewhere that the issue isn't just about making pedals easier to install, but it actually helps the torque reading you get with the wrench. Without grease, the friction on dry threads messes up how tight it feels, so you might think it's properly torqued when it's actually way overtightened. Grease gives you a more accurate feel for how much force you're really applying. Plus, it stops that nasty galvanic corrosion between the steel pedal spindle and aluminum crank, which is exactly what locked yours up. It's like a cheap insurance policy for a part that costs a lot more to replace than a tube of grease. I'm just glad your crank survived, some folks aren't that lucky.

harris.uma1mo ago

And yeah, I learned that lesson the hard way too. A little grease basically stops the threads from seizing up from mud and moisture. Now I don't even think about it, just a quick smear before spinning them on.