Topic: Fork swap: stem diameter

[stereosilence]

I just started my fork swap and am running into the issue described here: http://forums.sohc4.net/index.php?topic=27159.msg277362#msg277362

I don't understand how this was handled. Was the upper hole of the steer tube reamed out to match the lower?

[FunJimmy]

I assume you still need to purchase a fork & triple assembly.
It's a lot easier to understand when you have parts in hand.
The Yamaha R6 sheer tube is (essentially) straight.
30mm diameter for both the bottom & top bearings.
The Honda CB550 steer tube is not.
Diameter is 30mm bottom & 26mm top.

ALL BALLS will help you find bearings that fit this steer tube and the CB550 frame.
Easy peasy.

[stereosilence]

I have the entire front end. Here is my problem:

This stem should go all the way through the tube. According to my calipers, the opening is 28mm diameter, the stem is 30 mm diameter. So, the stem fits through the bottom no problem, but can't make it up through the top. Can I ream out that hole to a larger size with something?

[FunJimmy]

That is the top (ball) bearing race and should be knocked out.
Once removed the ALL BALLS tapered roller bearing race will press in.

[stereosilence]

Awesome! That is what I just heard on my build thread (link in my signature).

I'm going to go see if I can bust it off now.

[stereosilence]

Worked like a charm. When I took the front end apart it was pretty nasty so I didn't even know that part was frozen in there and not part of the frame. Thanks.

[754]

It is a hardened race..otherwise the bearings would wear thru it in no time..

Imaginethe hit the lower takes every time you wheelie and come down hard..

[FunJimmy]

Imagine the hit the lower takes every time you wheelie and come down hard..

Ya, cause that happens so often on a CB550

[stereosilence]

Poop. I accidentally bought the stock upper tapered bearing. Anybody want a new bearing for their 550?