BMX one piece crank removal

[Coyote]

Thought this would be the best forum to ask as BMX bikes are sport bikes :p

I'm currently fixing up my BMX after a life of torment. At this stage I'm trying to remove the crank to replace a broken ball retainer. Only I have a problem, the bearing cup closest to the chainwheel is stopping the crank from coming out. Has anyone here have to deal with this on their push bike? The bearing cups seem pretty secure and I have tried hitting them out with a flathead screwdriver and rubber mallet. How can they be removed? I want to remove them anyway as I want to paint the bike as well

[skidMark]

you usually shouldnt need to knock the cup out just get it so the sprocket is in clear area so you can wiggle it out if you get the right angle it will just pull out ...just takes perswasion...but if you cant do that stick a screwdriver or something in and knock out the bearing cup on the chainwheel side from the non chainwheel side that will make it much easier to get out. cup shouldnt be too hard to get out

[skidMark]

so the chainwheel is facing the underside of the bike basically (to the ground when right way up and youll get the angle very easily

[Coyote]

Both cups are solid and aren't budging. Whats annoying is the pic from my manual clearly shows them out and doesn't explain how to get them out.

I've tried persuading it in every direction but the bearing cup doesn't want to let go of it as the photo tries to suggest

[Coyote]

so the chainwheel is facing the underside of the bike basically (to the ground when right way up and youll get the angle very easily
Yes it is 10 characters

[skidMark]

sometimes they are stiff just keep trying to knock them out eventually the vibration will loosen them up you just have to work your way around the cup...one side then the next....they can be a bitc* to get out sometimes a block of wood on the end of a really big screwdriver usually does the trick

[marty]

i've got a nice 185mm 3 piece profile set going for $300 that would fit perfectly into there.

use a drift (or a 3/8 extension) and hit out the cup from the inside then the crank will fall out. you should fit new cups anyway - they are bugger all $$ wise. don't be afraid to hit it hard. it's only a diamondback after all.

[Coyote]

I'll give it another go trying to knock both cups out soon

[Coyote]

Also I'm having problems with the headset. I might be missing a part. The stem rocks inside the frame. Reckon this would help? http://www.trademe.co.nz/Sports/Cycling/Parts-accessories/Componentry/auction-44666600.htm

[Coyote]

Spent ages trying to whack them off but its not working. Only ended up crushing my thumb with a mallet

[skidMark]

a mallet...no wonder they won't come out use a fucking hammer LOL

[Coyote]

a mallet...no wonder they won't come out use a fucking hammer LOL
But this is a badass mallet. I did use a hammer however and it didnt work

[skidMark]

put your back into it lad :devil2:

[Coyote]

How have they been attached? Are they screwed, stuck or lock-tighted in? They seem way too solid

[skidMark]

they are just pressed in you just gotta go at them for a while to get em out....as long as the bearingings arnt still sitting in on each side you should just be able to wiggle the crank n it will pull out i don't see why you can't get it out:S and why the hell are you taking it out anyway?

you gotta think about the fact that....when they put the crank in the cups would have already been in you should just be able to take it out ive done it many a time

[riffer]

Dude - talk to Andrew at Cycle Center on Main Street.

He's a supporter of our local BMX Club (Hutt Valley Thunderbolts) and has been a mine of information for me with rebuilding Tim's Haro race bike.

He can help you out with weird parts too if you are stuck.

[Coyote]

you gotta think about the fact that....when they put the crank in the cups would have already been in you should just be able to take it out ive done it many a time
Can't see how they have, it's lodged in there fairly tight and it does look like one of them needs to come out for it too move. I need to get it out as the bearings are worn and the crank moves around. The one on the opposite side of the picture was broken in half

I've been making regular trips to the Cycle Center. They're good guys there. The bike originally came from them too. I'm trying to do the majority of the work myself but for the stuff I can't do like straighening the rims I'll get them to sort out.

[skidMark]

don't ya know how to adjust spokes?

[Coyote]

don't ya know how to adjust spokes?
Not really. Would be good to know. Half the spokes on the bike are broken or bent, same goes for my Mountain bike

[skidMark]

bike abuser i should report you to sifs (sp?) lol

[Coyote]

bike abuser i should report you to sifs (sp?) lol
It was mainly my friends who were 'borrowing' it. It's gone through 4 rear tyres in the last 6 or so months.

Anyone got some cheap MTB forks? I've always wanted to get some for the Diamondback

[marty]

get a couple of pieces of 4 x 2, and lay the bike flat over them, supporting the rear triangle and lower brace. hit the cups stright down towards the floor - they WILL come out.