Here’s an entry about 15 years late. The Rock Shox Paris-Roubaix SL fork, created to contest the legendary professional road race across the aged and treacherous country roads of cobbles in northern France. The fork was developed from the venerable Mag21 cross-country mtb fork; the main differences being modified internals and a taller bolt-on fork brace to accommodate a caliper road brake.
Did it work? Well, 2 consecutive Paris-Roubaix were won using that fork, so arguably it did. But the late-90s domination of the event by the Mapei team pushed road suspension out of the way, since Mapei’s bicycle supplier forbade the use of suspension forks. Rock Shox developed a ground-up road fork replacement, tritely named the Ruby, but that fork never caught on.
I have owned a Paris-Roubaix fork for more than 4 years. During the winter I use it because the fork gives better braking control on wet and bumpy descents on Seattle roads. I can also ride in the drops more comfortably at high speed, for longer periods of time. On cold, dreary training rides and commutes, I feel fresher and less stressed by the combination of cold muscles and punishing pavement. The fork doesn’t really help unless you are going faster than 18-20mph, though. Slower than that, and larger volume tires would likely be a better choice. And the P-R SL fork will not accommodate anything larger than a Michelin 25mm. Contrary to the elastomer and coil spring of the later (and from personal experience, inferior) Ruby fork, the Paris-Roubaix SL’s air-spring is easily tunable with air-pressure. The rider can also lock-out the travel by adjusting the dampers to maximum; the damper dials are on the op of each leg at the crown.
The fork also has two main drawbacks. The first is weight, and at about 2.6 lbs, the P-R SL is scintillatingly light for suspension forks but a gigantic boat anchor compared to an Easton or 3T carbon fork. The second is more annoying: the P-R SL, like its Mag21 forebear, is exceedingly flexible. Even under my weight, a trackstand puts the front rim against the brake pads. How I wish that Rock Shox would develop a road suspension fork with the features of the newest SID xc-fork. As it is, I cannot recommend my fork to any rider over 180 lbs.
I’ve customized my Paris-Roubaix SL fork. Since forks of the Mag21 family bolted together in many places that current suspension forks are either cast in one piece or are press-fit together, I have hot-rodded a 1-1/8” crown and steerer onto a fork that was only available stock with a 1” steerer. Also, back in the day before suspension forks standardized on 35-38mm of rake, Rock Shox made some forks with a 45mm rake. With the rake built into the crown and not the legs, this makes my fork probably unique with a the rake and steerer more suitable to my bike geometry. Well, not quite unique. I have a back-up P-R SL. They haven’t made these things in over a decade, so I’m planning ahead.
Thanks to HippieTech Suspension for doing the fork maintenance. Not a fast turn-around in my experience, but he does good work for these old forks.