Top Yoke Kawasaki gpz600r

Today I finished a nice little job. I really want a handlebar on my Kawa, so no clip-ons, no original gpz600r clip-on ish steer that came with  the forks The base is the standard stuff of a gpx600r. Why not use the forks of a gpz600r, the same bike is’nt it? No it isnt, the inner forks are 37 mm and the gpx are 38 mm.

Original Kawasaki gpx600r top yoke and handlebar mounts

I scored 2 items on our local ebay called Ebay tried it here but never succeeded in our country so in the end they just bought en left it as it is.

First item is a pair of KTM handlebar mounts and the seccond item is a cool Rizoma steer. But watch out and pay attention if you think like buying some. The mounts I bought are meant for 1-1/8 inch diameter mount area. That is 28, 6 mm. Another more common size is 7/8 inch, which is about 22 mm. It seems that motocrossers don’t like broken handlebars and therefore use a variant that is thick in the middle and tapered to 22 mm at the throttle and clutch ends. So a bit stronger but also less common.

Luckily for me a nice lady bought the wrong one for her bike, needing the 22mm version so they will be mine soon 😀

RIZOMA steer

To fit handlebars you can do a number of things. Looking for aftermarket parts suppliers and find a special top-yoke plate that fits the gpx forks, buy an adapter that fits on the original top-yoke plate. You can also make one yourself on a CNC machine, or with skils and mill it one a conventional mill. I went for the poor mans solution and took the original stuff and faced it down.

To mount the top yoke Iused the turning machine to make two brass  38mm buses. These buses are on the bottom side a nice fit of 14,7mm to the t-slots of the milling table, saves me the trouble clocking it straight. Its hard to mount the top yoke because its an aluminium casted part and the only machined surfaces are the 3 holes.

Start milling
Almost done!


Kawasaki gpz600r top-yoke Mount for machining

Beneath the risers that I found on our local Ebay, it comes from a KTM.

KTM risers or steering mounts
KTM risers or steering mounts

The best plase to drill holes for the risers is from the center of the yoke pen hole 38 mm to the right and up 29 mm, the left hole mirrored of course.

Kawasaki gpx600r adapted top yoke for handlebar.
Kawasaki gpx600r top yoke machined down to fit GT 550

Next project will be little disc to fill the gaps above the forks and a clean way to hide the central nut.

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