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Old 31st May 2019
Tomcatt Tomcatt is offline
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Summary:
My fork mods are pretty basic:
Springs
Spacers
Fork oil weight
Fork oil levels

The left (cartridge side) fork is more complicated than the usual damper rod fork. You might want the FSM and a fork spring compressor.

Remove and drain the forks and toss the OE fork springs and spacers. Pump the forks to get the oil out. On the left (cartridge side) you need to alternate pumping the fork/slider and pumping the cartridge rod. It's a PITA and takes a while to get the oil out.

After trying both 5 and 10 wt I settled on Redline 10 wt. 6 1/2'" level in the right (damper rod) side. and an 7 1/4" level in the left (cartridge) side. (See Edit) Setting the levels is IMPORTANT, make sure the forks are fully compressed and the cartridge rod is down when checking levels. 2 pints is enough for both forks.

Once your levels are set drop in the springs (Race Tech FRSP S2938095) (see Edit) then a washer (supplied with the springs) to protect the end of your PVC preload spacer.

Cut PVC pipe preload spacers. 3/4" PVC pipe, a piece comes with the Race Tech springs. A 2 3/8" spacer for the left (cartridge side) and a 6 1/2" spacer for the right (damper rod) side. On the right side put the OE washer on top of the spacer and reinstall the cap. The left (cartridge) side is a PITA with the retainer. It's PVC spacer, OE washer, retainer under the rod nut then the cap screws on the cartridge rod.

Put the forks back in the triple clamps.

Your new springs are being installed with ~ 1 5/16" preload instead of the almost 4" of preload the much softer OE springs had. Your forks will settle ~1/2" under the bikes’ weight. They settle another ~7/16" with my 200 lbs on the bike. About right for forks with only 4" of travel. Lighter riders will want lighter springs and might want to shorten the preload spacers but I'd try these specs first. It's easier to shorten spacers than lengthen them.

Enjoy. Now you won't cringe every time you approach a pavement seam...

Edit: I've since gone to slightly higher oil levels, 6" on the right, 6 3/4" on the left, and back to the lighter Race Tech FRSP S2938090 (.90 kg/mm) fork springs, same preload spacers. The ride is better with the lighter springs and the higher oil levels keep the forks off the hydraulic bottoming stops under heavy braking.

On the rear there are 13.26" Ohlins HD 916E shocks with the light duty springs. The forks are now nicely balanced to go with them.
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2017 XL1200C in SE Wisconsin, USA

Last edited by Tomcatt; 22nd January 2022 at 03:29.. Reason: updated
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