GS750E roller bearing headstock GSX1100E fork swap ?

[petrolhead]

I just got me a nice GSX1100E fork with air pressure support.
When I removed my old T-part from my GS750E 1977 8V i found to my surprise a roller bearing with loose balls.
Just like a classic bicycle
Not what I like to see on my retro racer...
Anyone with any experience swapping it for the conical bearing ?
Especially with a GSX1100E fork with 29.5 mm. stem ?

Keep on rolling

[yekrahs]

Allballsracing.com will have what you need...

[hillsy]

All the 1100's run 25 x 47 x 15mm upper bearing and 30 x 55 x 17mm lower.

Not sure where you are getting 29.5mm from unless you are measuring above where the bearing seats.

[petrolhead]

Thanks for the replies !
I live in Holland so I will try to find for a local supplier.
The width of the 750 headstock is 43.1 mm upper and lower.
The height of the bearing race 5.5 mm
So this might be a problem.
You're right Hillsy; I measured it wrong (above the race)

[hillsy]

Maybe you need some help measuring or some new Verniers. GS750 first gens have 48mm top and bottom neck bearing OD, not 43.1.

The 750 top bearing is the same ID as the 1100 stem so that's OK.

So for the bottom bearing you need to find a 30x48x15mm.

If you Google that you'll find it's a 33-1006 bearing.

[petrolhead]

Yes, you are right again.
Don't now why I'm having trouble reading the verniers these days...
But the problem is in the height.
The 5.5 mm height for the ball bearing is not enough for the outer race of the conical bearing.
So I went to the Dutch specialist today and he gave me a 750D frame suited for conical bearings !
Now I have to get the T-stem to the metal shop to have it rotated at 25mm
Thanks for the input !

keep on rolling

[hillsy]

The 5.5 mm height for the ball bearing is not enough for the outer race of the conical bearing.

Pretty sure you are only measuring one half of the bearing - you need to get the other race and the ball bearings together to get the full height. No way it's just 5.5mm......

Anyway, glad you found a solution.

[hillsy]

Now I have to get the T-stem to the metal shop to have it rotated at 25mm

Why do you need to do this? You just need a 30mm ID bearing.

[petrolhead]

about the ball bearing.
yes the complete race is higher but only the inner ring is enclosed in the frame tube.
There is very little height so a conical inner ring would be sticking out of the headstock.
I have the 2 frames next to each other to compare and the headstocks are different !
The newer frame still has the seat mounts; so that's a bonus.

about the T-stem bottom bearing.
I will see if I can find the right bearing, thanks for the input !

Keep on rolling

[hillsy]

If your new frame has the lower bearing OD of 55mm, then you need a 32006 bearing. If it's still 48mm, then you need a 33-1006.

The good thing about buying a kit from All Balls or Pyramid is you get a new dust seal for the lower bearing.

[mrbill5491]

Loose the air pressure system, you don't need it. A set of straight rate Sonic fork springs, 10 or a 15 weight fork oil with a set of cartridge emulators along with a fork brace and you'll have one hell'va of front end set up.

[petrolhead]

Ah, thanks for the input, just what I wanted to hear !
Do you tap the holes from the air pressure link and put small bolts in ?

About the bearings, I found out they are exactly the same as my Yamaha XJ 650 Seca...
(Still have a headstock in my crawl space...)

keep on rolling

[petrolhead]

Hello Mr. Bill,

You have got rid of the air support.
How do you plug the holes ?
Do you weld them ?