harris steering head bearing cup removal from frame

[baldrick]

Hello. Im doing up my old harris and have removed the bearings from the yokes to get them powder coated. Now the frame headstock.

What were harris playing at when they designed this. the bearing cups fit flush with the inside of the headstock tube, meaning you cant drift them out like 99% of bikes.

ANy ideas on how to get them out?

The best I can come up with is attempting to weld a short bar to the hardened steel bearing cup, and trying to drift it out by hitting this welded bar, or is there an easier way?

Do tell

[bluedog59]

The only other way I can think of would be to attack the bearing cup with a Dremmel. Once you've got it out it would be worthwhile seeing if you can put a couple of notches in the bearing seat to help next time. BTW, the welding method is equally good, it's more down to what kit you have to hand.

[Dezza]

If they are the same as on my Harris frame you can get them out in the usual manner if you are careful and have a small diameter flat ended punch to get things going. It's been a long time since I have done this but I think I used the 90 degree end of an engineer's pick to find where the cup meets the frame, and then scored it a little. Having someone to hold the frame still will also help here My Spondon frame is similar and has a very tiny lip where the bearing outer meets the frame but they come out using the above method. Once one bit has moved just a little then it's fairly straightforward to work your way round with a flat punch to get them out.

Edited October 29, 2019 by Dezza

[Fazz711]

You can also weld a small bead around the inside of the race. 

This will cause it to shrink a little. 

Should then almost fall out or at least make it easier to drift out. 

[baldrick]

i cant see me getting a flat headed punch in here to be honest, I think im gonna go with the weld option.

ive got a tig, but not that good with it, but I can always try, I suppose

heres what im up against.

check out the sweet photoshop skillzzzzzz

I got the bottom one out by drifting it, but it had a small lip (very small), this one is flush or even smaller than the frame, I think welding is the way to go. 

 

thanks for your advice tho.

Edited October 29, 2019 by baldrick

[FJD]

I would weld 

[clivegto]

Ring of weld is how I got my ones out as well. 

[bandit750]

would it be worth welding a penny washer to the inside, should shrink the cup but if not enough you have something solid to drift against?

[baldrick]

update, dont weld it, i did and it ovalised the frame headstock fkin great. 

Tried to fit the cup and its not even starting to go in, measured it, its 0.8mm out, froze bearing in the vain hope and heated headstock, still no dice

maybe mig would have had less heat but hey ho, its done now

off to the machinist on Monday see what he suggests. 

[clivegto]

That's bad luck, the ring of mig weld didn't do that to my one. 

[baldrick]

probably because you did it all theway round and it wouldnt have heated in localised spots.

oh well, proper engineer bloke reckons its fixable, thank fook. 

not really enough to bore it out to next size so the reamer is gonna ream. Might have to loctite the bearing shell in, depends on how much contact area is left, hes confident it will be about 80% contact area at least. 

Just got to wait till he can fit it in.