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Discussion Starter · #1 ·
How universal (if at all) are the threads holding the fork bottoms onto the slider tubes on 43mm USD forks?

The specific thing I want to do is remove the bottoms from a set of KTM Duke 690 forks and swap on a set of GSX-R750 bottoms.

I want to do this because:

1. The Duke 690 has nice USD forks that should be long enough to swap onto my CBX without decreasing ride height (although spring rate and valving will have to change).

2. The Duke 690 has only a single brake rotor and I want dual.

3. A GSX-R front end including brake calipers, master cylinder, and 2 bent forks can be picked up for not much more money than just a set of calipers.


They're both 43mm forks - any chance this is doable?
 

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Discussion Starter · #3 ·
any time i've helped remove fork bottoms it was to replace the tubes, and the old ones got royally fucked in the process
That's helpful information.

Did you use heat on the bottoms? I assume that it was a vice that royally fucked the tubes?
 

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Discussion Starter · #5 ·
lots of heat, and yeah, a vice , if we wanted to keep the tubes i would have made a clamp similar to one side of a yoke (triple)
Thanks, that's good to know.


I called a buddy who is a suspension guru and he said that he's done it in the past, but it's a crapshoot. That both forks are 43mm does not mean that the Showa parts from the GSX-R will fit on the WP forks from the Duke 690. But that they're different brands also doesn't mean that they won't fit.

The only way to know for sure is to get both parts and try it.
 

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Discussion Starter · #7 ·
After doing a bit more digging, it seems that the Duke 690 forks are about 4" too long, while Multistrada 1000DS forks are just right. And they are Showa 43mm forks - same as GSX-R 750 & 600. So I think I very well may go this route instead. We'll see.
 

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Discussion Starter · #8 ·
After doing a bit more digging, it seems that the Duke 690 forks are about 4" too long, while Multistrada 1000DS forks are just right. And they are Showa 43mm forks - same as GSX-R 750 & 600. So I think I very well may go this route instead. We'll see.
A little update on this...

GSX-R750 and 600 went to 41mm in 2008. I don't know for sure what the tube dia is on the Multi, I was assuming that basically everything is 43 when that clearly is not the case.

The Multi forks are now irrelevant anyhow, as it appears that the Tiger 1050 forks are about the right length AND have radial caliper mounts.
 
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