I bought Race Tech fork springs for my 2016 RC390. I am confused about how much to shim them.
The only instructions in the package said to see the Rectech website, which I did. That site said to set ’Preload’ to 10mm. I am not sure how to put that into practice on the RC390. I presume it is done with shims/spacer tubes, but I don’t know if they are saying to install only 10mm of spacers in total, or what. I don’t think that could be right, since the new springs are 30mm shorter than the stock springs. Maybe they want enough spacers installed so that the cap compresses the spring by 10 mm when installed; but that seems rather clunky to figure out.
Other items I found in the package you sent were some washers totaling 12mm in thickness (6mm per leg), plus a lengthy piece of metal tubing.
When I disassembled the forks, I found that each of the stock forks had three nylon shims on top of the springs, two black ones sandwiching one white on, and totaling 12mm.
Do I leave these the in place and add more spacers?
Thrown them away?
Put a 40mm slice of the tube atop each spring (30mm to make up the difference in length from stock, plus 10mm for the recommended preload)?
Something else entirely?
Help!
One other thing: RaceTech uses a mm measure for fork oil height, instead of the volume method in the KTM service manual. Do they both accomplish the same level?
Thanks!
The only instructions in the package said to see the Rectech website, which I did. That site said to set ’Preload’ to 10mm. I am not sure how to put that into practice on the RC390. I presume it is done with shims/spacer tubes, but I don’t know if they are saying to install only 10mm of spacers in total, or what. I don’t think that could be right, since the new springs are 30mm shorter than the stock springs. Maybe they want enough spacers installed so that the cap compresses the spring by 10 mm when installed; but that seems rather clunky to figure out.
Other items I found in the package you sent were some washers totaling 12mm in thickness (6mm per leg), plus a lengthy piece of metal tubing.
When I disassembled the forks, I found that each of the stock forks had three nylon shims on top of the springs, two black ones sandwiching one white on, and totaling 12mm.
Do I leave these the in place and add more spacers?
Thrown them away?
Put a 40mm slice of the tube atop each spring (30mm to make up the difference in length from stock, plus 10mm for the recommended preload)?
Something else entirely?
Help!
One other thing: RaceTech uses a mm measure for fork oil height, instead of the volume method in the KTM service manual. Do they both accomplish the same level?
Thanks!