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Fork swap project

787 Views 5 Replies 3 Participants Last post by  Norm
Good morning. I'm in the planning stages for replacing the Marzocchi forks on my '98 900CR with some adjustable Showas from a '99 900SS ie. So far it looks like the forks have the same diameter so I can keep my triples and Heli bars. Calipers are part of the deal, so the 65mm vs 40mm difference is a non issue as well. I'm currently running Marchesini mag rims on the CR, so I can't swap out rims. This leaves me with a 20mm axle and new forks that require 25mm. Apparently, I can have a spacer made that will fit the difference, but I have no idea how to go about securing one or what the dimensions would be. If anyone can provide any info regarding that issue I'd be very grateful. Also, I'm told that my current speedo housing should be compatible with the new forks as long as I keep my 20mm axle. Makes sense to me. Again, can anyone offer any info that verifies this?

I appreciate your feedback.

best regards,

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I would look for bearings first. that seems like the better way to go.
Thanks for the tip! Do you mean that I should be looking for bearings to convert my rims to a 25mm axle? Sorry, but I'm pretty ignorant regarding this sort of thing.

You can use a piece of 1" sewer PVC for a spacer. Just slit it down the middle so it clamps with the fork. Schedule 40 water pipe is too thick, make sure you get the drain pipe.
If you swap bearings, you'll have to make precise spacers (2mm?) because the 25mm bearing are narrower than the 20mm. You'll also need a new center spacer & a new speedo pick up.
Thanks again Norm! I went by my Duc shop and verified your thoughts. The bearing for my 20mm axle is 20x47x15 where the 25mm bearing is 25x47x12. I'm thinking your right about having the spacer made...
Been there - done that.
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