Anyway, I managed to source them from a friend who has an allez so had a few spare laying around. Sorry if I annoyed anyone with my question, the numbers initially baffled me.

I did try to fit them yesterday and the top one fit without issue. the bottom despite being the same measurement when i compared it to my old one, wont fully seat into the headtube, is it normal for new bearings to require a bit of a hit into place? Dont want to hit the bearing if it should just fit easily without force.

Good lord, the a$$#0les really came out for this thread.

If the OP felt comfotable knowing exactly what to look for, he would not have started the thread.

BTW, if I wear out a headset bearing in under a year, I would probably get the head tube faced (if it was not already done) before spending the money on another bearing.

Even a cheap bearing should last a very long time in a properly aligned headtube, whereas the nicest bearings out there will get destroyed in sort order if the head tube is off.

The only two headset bearings I have EVER worn out were in new frames. In each case I got the head tube faced and the replacement lasted indefinitely.

Most modern non-BSO frames don’t need the head tube faced these days, but sometimes they do

Yes, it is normal to press a cartridge bearing in to place. The idea is the tight fit prevents any slop so that every bump you hit doesn't have a running start to smashing into the bearing. Generally, the fit should be tight & require a bearing press. Though there are also headsets that fit hand tight.

I had a headset that developed a bit of slop in the crown race. Eventually the steerer cracked when I was braking very hard & hit a pothole. It was an interesting ride home.

Make sure the bearing is not upside-down when you install it. The outer 45 degree chamfer goes to the cup; The inner chamfer goes to the crown race. Don't forget to install the cartridge with a bit of grease to prevent any creaking. You should be fine.

I’ve never had to tap a “headset” bearing into place, sealed or otherwise. Even more so, if the old bearing fits easily.

If you have digital calipers, you can measure old and new bearings and make sure they are the same.

Obviously if it measures out correctly and bearing number is stamped on the new bearing, it brings up questions if the cup was damaged.

John

Yeah, measurements were identical so weird the old one fit without much issue. The new one went in quite easily but wouldn't fully seat so I had to force it a bit and then followed an hour of using a soft blow hammer to get it back out as it was lodged in an angle. Very longgggg, i will try fitting it again tomorrow being careful to push it in as square as possible

I don’t have the background to state that the head tube ends not being faced and not parallel will cause a deformation of the cup.

I think the above suggestion about non-faced head tube has merit based on bearing longevity and the tight fit of the new bearing. With the pounding the headset takes it is within reason.

Spending a hour to remove a cartridge headset bearing, is not within reason.

John

I agree, although I think this was error on my part by pushing in the bearing too much on one side causing it to be lodged at an angle

In all the headsets I have worked with with cartridge bearings (I’ll guess 30?) not one needed to be pressed or tapped in. They should go in and out very easily. Heck they sometimes just fall out.

yeah, not ideal. Perhaps poor tolerances on my frame!

Il try one more time tomorrow and then I will take a trip to the LBS

I had the same issue when I installed the lower bearing also. Park makes a tool, a tube that slides down the headtube to keep it square as you tap down. I didn't feel like buying the tool for something I would seldom use so I used a piece of PVC pipe that fit around the head tube and tapped the bearing into place with it. Worked great.

ah good to know its not unheard of. was yours a threadless sealed bearing too?