Outer Bearing Races

[Adrian]

Hi again - the next step is to fit the steering head races - My Clymer advices putting the races into the freezer for 30 minutes or so - and the BMW genuine workshop manual - of which I have a PDF - advices a block off wood over the top of the races and a reasonable size hammer used sensibly.
.
The old races got thrown way by the shop that took them out so I don't have the old ones to use as a drift. Any suggestions would be so very welcome ....... Adrian

[Justin B.]

See if you can find a socket the right diameter...  Freezing sounds good as it will shrink them a bit and you probably won't have to whomp on 'em as hard, if you are quick between freezer and bike.

[Adrian]

Thanks Justin. I'm also going to I heat up the frame in.That area as well. I have of all things a steel shower drain.cover that is the right diameter for the race. Fingers crossed :-)

[georgesgiralt]

You can also buy an extra bearing and use it's race as a drift.

[Adrian]

Yep thanks George - I am thinking about doin that -)

[Justin B.]

If you warm up the frame, and freeze the race, it shouldn't take much "persuasion" to get it installed...

[Adrian]

Thanks Justin - the frame is powder coated but I should be able to heat it to about 100 degrees C without damaging the coating as its put on the frame at about 200 degrees. I'm having a break over the weekend and will try on Monday :-)

[georgesgiralt]

Adrian,
I do hope the powder coater man protected the hole from being powder coated. Otherwise, the Dremel is called  to clean the tube to show the bare metal before trying to insert the bearing races...

[Adrian]

yep all good George :-)

[skippyc]

I'm in the process of removing mine and replacing them, so i will be interested in how you get on.
The outer race on my bike is flush with the steering head is that correct.

[montmil]

I'm in the process of removing mine and replacing them, so i will be interested in how you get on.
The outer race on my bike is flush with the steering head is that correct.

Drive it down until it seats. If left slightly off the seat, you'll be stripping it within the first 100 miles of riding.

[Bob_Roller]

I don't know if this is widely available, but two of the local grocery stores have dry ice for sale, it's sold by weight not expensive at all, about $2.50USD for a pound, .5 kg .

I've tried it a few times with assembling things with a close tolerance fit and works great .

[skippyc]

What a pain removing the bearings. I used the welder on the shells and made puller ends and extensions to pull the bottom bearing up after removing the cage.
Is an aluminium vacuum cleaner pipe good enough to drive the bottom bearing down after heating the bearing?

[georgesgiralt]

Cycleworks made very clever tools for removing the races. And no so expensive.
I used them for the steering column, swing arm and rear wheel. Very good and easy job.
Do not freeze the races too deep. As heat, cold is used to temper  steel.
IMHO, a freezer at around -18°C is OK. But around -100°C is not.
On the other hand, when heating do not exceed 100~150 °C.

[Tony Smith]

What a pain removing the bearings. I used the welder on the shells and made puller ends and extensions to pull the bottom bearing up after removing the cage.
Is an aluminium vacuum cleaner pipe good enough to drive the bottom bearing down after heating the bearing?

An angle grinder works a treat on the bearings, once you have the cage and rollers cut off you and either gently work over the inner race until it comes free, or if you are worried the time old method of 4 90 degree spaced cuts with a sharp cold chisel will usually expand the races sufficiently.

Aluminium Vacuum cleaner pipe is unlikely to be strong enough to seat your new bearings - Alloy/steel pipe is required. You can of course freeze the bottom yoke and heat the bearing I guess - I've always just flogged them on.

Whilst you can buy the bearings far cheaper from your local bearing shop than from any BMW parts supplier - do buy the bottom "seal" it really does do an important job.