'01 Katana triple on '78 GS 750

[Dignan]

Howdy, all.

So I laid my bike down about a month ago ('78 GS750e), it hit a fence and bent the forks. Bummer. Luckily I didn't get hurt.

I have an '01 Katana parts bike that I've taken all the good stuff off in the hopes of upgrading my bike. I also have an 1100 swingarm & I can figure the back end out. My problems lie in getting this triple tree in the neck of my frame.

The Katana steering stem is the same length & diameter, except for the bottom where it flares out. This part is 3mm thicker. My lower bearing race won't fit on the Katana neck & the Katana bearing won't fit in my GS frame.

Questions:
- Does anybody know the outer diameter of the lower bearing in an '01 Katana?
- Does anybody know if there's a bearing available with the same i.d. as an '01 Katana with a 3mm smaller o.d.?
- It'd be dumb to press the neck out and machine 3mm off the bottom in order to press my lower GS race on, right?

Info that might be helpful-
- GS bearings are loose ball bearings, with lower races being like a "cradle".
- Katana bearings have cages, and half-races (sorry, I obviously don't know the tech terms).

Thanks for any input!

 

[mriddle]

First, glad you were not hurt !


I am attempting a similar upgrade (different bikes) so I have a couple of resources that some guys have posted that may help you.

I have not done the change yet.

A PDF with info for determining the size of the bearings in different bikes can be found here >>
http://www.ohiocaferacers.com/OCRStemSizes.pdf

The measurements are in mm and go (inner diameter, outer diameter, height)

A recommend source for bearings is >> http://www.goallballs.com/dealer_tools.asp

Go to PART SPEC LOOKUP
--------------------------------

I think you need the inner diameter of your NEW STEM and the outer diameter and height of your OLD setup.

If you can find the newer type (tapered) bearings, with the correct dimensions, you may not have to have your stem modified.

The more experienced folks on the forum may have info to add (or correct).

Good luck with this and keep us posted.

Mike

 

[Dignan]

I love this place

I love this place

Thanks, Mike! That was a big help.
I need a 30x48x14, which according to that list Kawasaki seems to like. Bunch of bikes with that size. I just hope they're the same style.

That size not offered on "all balls".

New question-
If the Kawasaki bearing is like the Katana bottom bearing, it has the "half" inner race that presses onto the stem, the ball bearings that snap into the basket, and the outer race in the neck. Does anybody know if the race in my steering neck will work with this newer-style bearing?
If I don't hear anything, I'll buy this bearing and be the guinea pig. I'll let everyone know how it goes.

 

[Frankenzuki]

front end

front end

Hi,

I'm pretty sure I have a Katana triple clamp setup for an early gs750 chassis. Let me know if that sounds like an easy way out for you and I'll see if it is still in the shed

 

[dardoonk]

Is your Katana triple tree from a 2001 Suzuki GSX750F?? If so, a parts search shows it uses the same bearings as the 85 GS700. If the link pic is what you you have, then the info I posted in another thread about the GS700 may work for you.


GS750 Bearings (this is what my 750B had, yours should be the same)
Upper: 25mm x 48mm x 16mm
Lower: 27mm x 48mm x 14mm
(ID X OD X Hight)

The GSX has different dimensions, so they are not interchangable:

GSX Bearings
Upper: 25mm x 47mm x 15mm
Lower: 30mm x 55mm x 17mm
(ID X OD X Hight)

To swap the whole front end, in which case you would need to order from All Balls Racing and get the correct sizes.

To swap, you would need:
Upper: 25mm x 48mm x 16mm (AllBalls # 99-3507)
Lower: 30mm x 48mm x 14mm (AllBalls #99-3503)
(ID X OD X Hight)

 

[Dignan]

I tried to spec that lower bearing out on all balls and didn't find it. Same when I search that PN. I emailed them with the specs & part number you gave me.. I'll post their response.

Otherwise, I'll take your setup Frankenzuki. Really appreciate the offer. Hopefully I'll know my plan of action tomorrow.

 

[dardoonk]

I tried to spec that lower bearing out on all balls and didn't find it. Same when I search that PN. I emailed them with the specs & part number you gave me.. I'll post their response.

Otherwise, I'll take your setup Frankenzuki. Really appreciate the offer. Hopefully I'll know my plan of action tomorrow.

Use this link to Dealer Tools

http://www.goallballs.com/dealer_tools.asp

Go to bottom right " Part spec lookup" and select "tapered bearings" from the dropdown. Put in you the dimensions & you'll get a long list.

 

[Dignan]

Here's the response I got from Alex @ all balls:

The kit you need is a 22-1015. The dimensions are as follows.
Top 25x48x15
Bottom 30x48x15


So the top will be 15mm deep instead of 16 & the bottom will be 15 instead of 14. Tapered roller bearings instead of loose ball bearings. Sounds good to me. Now to get the races out of the neck...


Thanks again, everybody.

edit FYI- Installed that bearing kit last night, and it fits just fine. The old-style races that I had are easy to pop out of the neck, too. If somebody had the parts all together & ready to go, they could probably take the old stuff off & have the bike back on the road with the new front end in an hour.