So I heard back from Steady Garage about the RacingBros anti-dive fork kit. Apparently the 10” spring is intended to be used. In combination with the 5” spacer tube and the longer top cap, this compensates for the difference with the oem 16” spring. Apparently the stock rebound spring, pipe, and piston ring remain in the tube, and the only oem parts not used are the springs and top caps. A key component is the adjustable valve, which sits in the oil below the spring. FWIW, all the parts look very well machined. It will be a few months yet before I’m riding, so I won’t be able to report how the kit impacts the ride until then. Hoping someone in a milder climate will post a review before me.
Here’s the response from Steady Garage:
“Thanks for your patience. We were awaiting for an answer from one of the engineerings.
It has been confirmed from RacingBros that the original spacer tube would need to be reused. It would be as follows going into the fork tube first: Anti-Dive Blue Valve, Racing Bros Spring, Racing Bro Spacer Tube, Racing Bros Washer, OEM Space Tube, Racing Bros Top Cap.
Please let us know if you have any questions!
Thank you!
-Steady Garage”
Below are pictured the preload adjuster top cap and the adjustable damping valve.