How to extract tricky head bearings from frame?

(EDIT - this first post is now irrelevant, please scroll to post no.4!!)

Hi all, my scoot got failed at MOT due to fork wobble. So I got the forks off, and the bearings I took out don't look like the ones for sale, or the ones shown in the Aprilia diagrams online.

The diagrams show the upper and lower head bearings each being a pair of circular runners/cups, and then a set of ball bearings each to go inside.

When I took my forks out, all I found for the bottom head bearing were a bunch of loose ball-bearings sitting in a groove on the fork (not enough to fill it either, space for 3-4 more), and a corresponding groove to the underside of the frame. No cups to replace. The top one had an upper cup only, then ball bearings again sitting in a groove on the frame.

Is this normal, or were these ones fitted by cowboys (I know from the service history that the head bearings were changed once already)? If there's no cups to replace how are you supposed to make good on the wear to the grooves?

Any thoughts much appreciated, cheers

 

The bearing cups are fitted into the frame, you need to knock them out to replace them.

 

Yes as marsh said. Plus some bikes can come with just loose bearings in them. My aprilia has loose bearings in the bottom and caged ones at the top.
That reminds me i have to change mine. (I didnt know they fail mot haha

 

OK you guys are right of course, they're just wedged in so tight they looked like part of the frame to me. So I'm gonna change the subject of this thread slightly - who has experience of using bearing pullers? The top head bearing in the frame has an inner lip and I should just be able to knock it out, but the lower bearing has the same inner diameter as the tube it's fitted in - there's only the slight groove between the two to get any purchase.

Most bearing pullers I'm seeing (just the 10-20 quid ones) seem to have a centre bolt designed to do all the pushing, but there's nothing for that to push against in this case. It would just go up inside the tube. Any ideas how best to go about this?

 

I use an old long pry-bar with a slight bend at the end, put it down the steering tube and get someone to force it over in the edge while you hit it! Other times I've had to use a dremel with cut off discs to cut a groove in the race to free it then poke it out. It can be a bitch off a job!

 

Well I decided to spend 30 quid on a "Sealey MS040 Steering Stem Race Removal Tool" - or should I say waste 30 quid, as the f@cking thing claims it can do 30-68mm bearings even though I can't fit it inside my 35mm one!

A pry bar isn't an option as there is no lip and so no purchase, so cutting might be the only option. Is it possible to cut a groove into the bearing without cutting into the frame?

 

Yes, it's an arse of a job but doable !

 

Well I'm no closer. I bought a cold chisel, as recommended elsewhere - the tip was destroyed within two minutes. I'm back to using this thing that I got while rooting around our local 2nd hand emporium. Looks like a glorified tent peg with a wedge end, but at least it's not made of cheese like that POS chisel. I've bashed and bashed and made a few little notches in the race but that's all.

 

Well, for the benefit of the curious and future generations - I finally got the thing out, but I'm not too happy with how it went down. I ended up getting a 2nd hand dremel and going to town on it with that. It still ended up very messy. I nicked the frame a few times with the dremel, which wasn't so bad, but my efforts with the chisel where I tried to get the tip in between the race and the frame just ended up damaging the frame (not to mention random other notches I made with mis-strikes).

I ground back the rough parts and burrs in the damaged areas and then touched up the exposed metal with some hammerite.

I think in future I would try to cut a horizontal groove in the inner edge of the race, as near the top as I dared without cutting into the frame. Then chisel into that.

 

As long as you sorted it, I've had to exactly the same in the past on various scoots !

 

Ive had to weld on one before...
Hate doing stem bearings...