Front disk wheel bearings

Hello,

I'm trying to change out the wheel bearings on a spare front wheel pre-MkIII wheel that I bought off Ebay several years ago. I got the bearings in, but they don't want to turn. Maybe one could be cocked? They look straight. The way I understand the thing works is that when you tighten down the nut the shoulder on the axle presses on the left dust cover, which presses on the inner race of the single row bearing, which presses on the spacer tube, which presses on the right side dust cover which presses against the right fork leg, so I wouldnt' think you could put the bearings in too tight. That being said, I just reread the instructions on reassembling the wheel and they said to press the double row into place using the axle. I did it by using a socket against the outer race, so I wouldn't be transmitting the taps through the bearings. Perhaps by pushing the double row bearing in from the outside, the preload of the spacer tube on inner race of the bearings is causing them to bind?

Is there a way to get the thing apart other than to do use a drift against the inner race of the single row bearing? My drift keeps slipping on the inner race the sealed bearing I put in there. I've heated the thing with a tea kettle, but it still won't budge. A heat gun won't do much on a hunk of aluminum this big. Maybe if I grind down the tip of my drift it will bit a bit more against the inner race? When I get the thing apart, I wonder if grinding a little bit off the "wings" on the spacer tube might let it wobble a bit more when you're trying to drive the bearings out.

-Eric

Eric,

Did you turn the spacer down to accommodate the wider sealed bearing setup?

bpatton said:

Eric,

Did you turn the spacer down to accommodate the wider sealed bearing setup?

Click to expand...

I held it up next to the bearing that came out, it didn't look any wider than the original. I would think that the bearings would stop against the shoulders in the hub, so the spacer width wouldn't matter.

-Eric

It's been years since I made the sealed bearing mod on my front wheel but the sealed double row bearing is wider. I followed Fred Eaton's instructions and turned down the spacer by 0.056". You can see his instructions on their website by bringing up the parts list and following in the 'alt' parts available for the bearing and clicking the sealed bearing option. "Wheel Bearing Upgrade Instructions."

ewgoforth said:

bpatton said:

Eric,

Did you turn the spacer down to accommodate the wider sealed bearing setup?

Click to expand...

I would think that the bearings would stop against the shoulders in the hub, so the spacer width wouldn't matter.

-Eric

Click to expand...

That applies to the single row bearing but not the double row. It seats against the spacer and needs to be free in the hub.

bpatton said:

It's been years since I made the sealed bearing mod on my front wheel but the sealed double row bearing is wider.

Click to expand...

However, there doesn't appear to be any problem obtaining the correct width double-row sealed (2RS) bearings now.

bpatton said:

ewgoforth said:

bpatton said:

Eric,

Did you turn the spacer down to accommodate the wider sealed bearing setup?

Click to expand...

I would think that the bearings would stop against the shoulders in the hub, so the spacer width wouldn't matter.

-Eric

Click to expand...

That applies to the single row bearing but not the double row. It seats against the spacer and needs to be free in the hub.

Click to expand...

That must be what's wrong, I must have driven the double row bearing a bit too deep in the hub. By the way, I'm not using a sealed double row bearing, just the single row bearing is sealed.

-Eric

Ive just built up my 74 850 single disk stock hub. New bearings double
row from Andover single stateside both sealed.
Unlike the problem of too tight mine seems too loose! Both were drifted
down to their shoulders with stock unskimmed spacer inside. Ballpark
guess on the gap? Uh, not a lot. 40 thou maybe?
What am I missing?

The axle step bares on the slider leg bore to pull slider against the spacer/dust cover, ie: axle will not pass all the way through sliders.

In perfect world the outer races seat in hub just as inner race spacer gets clamped. I'd had factory open bearing/spacer make the screw ring not seat flush down with hub and another with sealed bearings leaving the spacer to flop inside as turned. But should not matter a whit worth as long as the slider ends are not too close or too far apart that it binds the fork action out of parallel, the wheel won't care.

The front axle ain't under much side loads so no need to squeeze side loads on bearings w/o spacer back up, than enough to keep the nut on.

Alas to get bearing back out means impact shocking the balls more than axle clamp would. I've ended up breaking hand and crying-runing into woods blindly trying to catch bearing edges with a spacer fully trapped immobile to move aside. I now grind out 3 V notches in one end of spacer to ease the next fella's trauma. This is is another of the times I grab 3 lb sledge and no longer show any mercy to get bearings out brute fast then start again as polite proper mechanic.

Ill have to drag out the sliders and have a look. Thx.