Changing a crank set???

[ak_powder_monkey]

So how do you change a crank set on a square bottom bracket? i took out the bolt but it still won't come outbut I can't get the cranks off how do I do that? Is there a trick or just brute force?

[cumerritt]

a little brute force might be good, but so would a crank removing tool. go buy one at your LBS.

[powderhound]

you let us know if you can pull them without a tool and damaging your bike

[ak_powder_monkey]

I got the bolts out the cranks there must be something else though hmmm

[White Chocolate]

Originally posted by ak_powder_monkey
I got the bolts out the cranks there must be something else though hmmm

take a really big hammer, preferrably metal, and bash your crank arms near the pedal holes until they pop off. Don't worry, they'll come off eventually but you really gotta bash hard.

[Plakespear]

Originally posted by White Chocolate
take a really big hammer, preferrably metal, and bash your crank arms near the pedal holes until they pop off. Don't worry, they'll come off eventually but you really gotta bash hard.

This method works really well if you want to damage your cranks. Buy the proper tool for the job.

[Mountainman]

Originally posted by Plakespear
This method works really well if you want to damage your cranks. Buy the proper tool for the job.

Well ya know, he never really specified if he wanted to damage them or not. He just wants it off!!!

[jayfrizzo]

Originally posted by powderhound
you let us know if you can pull them without a tool and damaging your bike

That's a crank puller (heh) and won't help him get his BB off (other than you have to take cranks off to get to the BB).

AKPM, if you've never done it take it to a bike shop. Or buy a book and the right tools

BBs on mountain bikes are threaded -- they screw in -- and you'll probably need a special tool to get 'em out, depending on what kind you have.


J-

[powderhound]

after further review, i don't understand what you are trying to do
Are you trying to take off the arms that hold your pedals? Or the crankset?

[CS]

Originally posted by powderhound:
Are you trying to take off the arms that hold your pedals? Or the crankset?

Those are one and the same.

[powderhound]

yes indeed

[Telenater]

I believe that he's trying to remove his crankset from the bb.... But I could be wrong. He might just be trying to change the inner chain ring.

[powderhound]

by this time he has the whole thing fuckered up.

[UTdave]

use a crank puller to remove crankarms from the bottom bracket spindle. If you intend to remove the bottom bracket use the proper bb tool and remember the drive side of the bottom bracket is left hand thread. if you are already pulling the crankarms you might as well remove the bb to clean and grease the threads.

[jayfrizzo]

Originally posted by Telenater
I believe that he's trying to remove his crankset from the bb.... But I could be wrong. He might just be trying to change the inner chain ring.

I think you're right. I read it wrong, cause I am dum.

I've banged off crankarms using wood as a tap to not mess up the aluminum by hitting it with a hammer.

But crankpullers -- the thing powhound posted -- work much better.

[ak_powder_monkey]

Yeah I'm trying to get the crank set off leaving the BB on, I removed the two bolts this crank puller thing how does it work?

[powderhound]

the black piece with threads screws into where the bolts came out, then you turn the blue handle, repeat for other side. to reinstall cranks put cranks on and tighten with bolts you took out, make sure they are very tight

[flowtron]

This has been a funny thread.
The only remaining issue is that he uses the correct crank puller, the one pictured is for splined BBs, its got that wider diameter plate on the tip. If you go buy one, make sure you get a square taper kind. When you put the cranks back on be sure to clean the hell out of the BB spindle surfaces,rubbing alcohol works well, evaporates with no residue.
Then we'll all argue about whether or not you grease the spindles, I've recently changed my vote to no grease...just real clean.

[jayfrizzo]

Originally posted by flowtron
Then we'll all argue about whether or not you grease the spindles, I've recently changed my vote to no grease...just real clean.

Pfft, clean, no grease -- what an idiot!



Just don't do what I did: Get some cranks in 1997. Grease the spindle. Never grease or clean it again, even when reinstalling in different bikes. Though, my cranks still work fine. But they're Profiles. One good thing about buying good stuff and being a beater is that it lasts forever.


J-

[flowtron]

Originally posted by jayfrizzo
But they're Profiles. One good thing about buying good stuff and being a beater is that it lasts forever.


J- [/B]

Ahhhh, Profiles...hence the "use a hammer advice". Thats one of the few times a mechanic won't get heckled or double taked..took(?) in the pit when the hammer gets busted out.

[Big Hit77]

Flow-Why no gease? Does this help things out?

[flowtron]

It is genrally thought that with grease its possible to push the cranks too far up the spindle flat surfaces, damaging the cranks.

This is only for square taper BBs/cranks...with splined systems grease em up like you were a monkey who worked at..uhhh..Grease Monkey.

Honestly, I've used just the tiniest amount of grease possible (get it to a film on my fingers then lightly apply to flats) on the spindles for a long time with no ill effects. I felt it gave me a better idea of torque on the crank bolts, but I've changed my ways and now just clean the hell out everything: spindles and surfaces in the crank holes.

I've said waaaay too much here.

[jayfrizzo]

Originally posted by flowtron
I've said waaaay too much here.

No way, dude. Let's beat this into the ground.

I learned you're supposed to grease to keep the aluminum in the crankarm from fusing with the steel in the spindle. So do you need to grease with something like a profile, that's CroMo on Cromo?

<hijack > Also, where in SLCizzy do you ride? Trails? Street? DJ?


J-

PS: I just remembered I figured out a way to get Profiles off W-O banging on the crankarm. Take off both bolts, get a 2-inch bolt that'll thread into the spindle and thread it in halfway. Tap it.

[ak_powder_monkey]

Originally posted by powderhound

the black piece with threads screws into where the bolts came out, then you turn the blue handle, repeat for other side. to reinstall cranks put cranks on and tighten with bolts you took out, make sure they are very tight

Perfect just what I need,

here are no more screws onto the bb though right? I'm using old crap and just making my bike work so a hammer should work fine (I'm gonna replace my whole drivetrain once I get the money)

[flowtron]

The thought of a hammer still makes me cringe a bit..I've done it on bikes with the crank threads all stripped out and resorted to blowtorch use, but that was for replacement.
My vote is to take it to the coolest bike shop you know of and ask really nicely if they'll pop the cranks off for you. You don't need that tool to get them back on. It might be a few bucks or fo free...If they hook it up for free bring them some beer, just make sure they don't look Mormon or like reforming alkies....not so much of a problem outside of Utah I suppose.