LCGB Forums

Come to fit my pm tuning forks and the lower bearing seat (to house the bearing race)
won't go to the bottom of the forks where the fork stem widens. Do I need to heat the seat/ cup to get it on?

Hi Jim
when you say it wont got to the bottom where it widens how far off is it ?
Any chance of a pic?

I may have it the wrong way round but looking at the parts diagram it goes dust cover, seat, bearing.
Or does the seat fit up into the lower cup withe bearing sitting on the dust cover?

Phil D wrote:Hi Jim
when you say it wont got to the bottom where it widens how far off is it ?
Any chance of a pic?

Hello Phil, I've tried to post photo, can you see it?

You have it the right way,but the lower bearing race needs knocking onto the fork stem so that it traps the dust cover.

Is it supposed to be that tight?

How tight? The bearing race needs knocking on until it traps the dust cover.Then grease the bearing and fit the forks.

The seat the bearing sits in would need to be hammered down for it to go to the bottom of the fork stem and trap the dust plate

Thats how its done,its usually knocked on with a piece of tubing that fits over the fork stem and rests on the race.

HxPaul wrote:Thats how its done,its usually knocked on with a piece of tubing that fits over the fork stem and rests on the race.

Ok thanks

Place the bearing race in boiling water for a couple of mins will make things easier getting it on.

jonno wrote:Place the bearing race in boiling water for a couple of mins will make things easier getting it on.

Cheers bud

Forks outside in the cold, bearing seat in hot water, hammer and wooden stale......... It's on.
My next post will be when I try and and do the fork internals, just need to check forks fit frame.
Thanks everyone.

Sorry Jim .just seen the pic .(phone went flat and charger broke ffs)

The bottom race needs to be tight because it needs to stay put and not move. As Paul & jonno said it will need heating to give the clearance needed for it to be able to be fitted.
Avoid a blowlamp try steam from a kettle ,the forks should be bloody frozen if you leave them in the garage overnight .
I had a look at those forks you've got, do they have buffers ?
They look great dont know how they make em for the price
Can you post a photo or two when they're fitted

Phil D wrote:Sorry Jim .just seen the pic .(phone went flat and charger broke ffs)

The bottom race needs to be tight and as Paul & jonno said it will need heating .
Avoid a blowlamp try steam from a kettle ,the forks should be bloody frozen if you leave them in the garage overnight .
I had a look at those forks you've got, do they have buffers ?
They look great dont know how they make em for the price
Can you post a photo or two when they're fitted

Absolutely, I'm building an sx150 from scratch - frame only, really enjoying it but I need loads of tips and parts.

Im in the same boat great isn't it building one from a frame up.

I had the same problem with my PM forks ,even after heating up the race and freezing the forks the race split!
So in the end after measuring the fork and another race there was nearly 2 mm differance (hardly an interference or tolerance fit) I had to dremmel a bit off the fork for the race to fit.
And you ring to explain and they have no clue, it's not rocket science ,And I used to do that!

I seem to remember I had the same problem with the PM forks but I have a few lower races so I find one that fits as they can be different sizes.