THROWBACK THURSDAY: MBA’S 1989 REVIEW OF THE FIRST ROCKSHOX SUSPENSION FORK

Bicycle suspension? A pipe dream! Rube Goldberg devices! Not practical! Too heavy! Too flexible! Unnecessary! Those are the responses that the MBA wrecking crew got every time it mentioned mountain bike suspension systems. Shop mechanics would groan at us. Marin County granola-eaters would chastise us. Even our buddies would look at us askew. But, we just smiled and took the abuse.

Why did we turn the other cheek when faced with ridicule and derision every time we mentioned bicycle suspension? Because we had been riding a set of Paul Turner’s Rock Shox forks on our test bikes throughout the winter, and we knew that it not only worked, but was going to be the measuring stick that all future forks would have to size up to.

WHAT ARE ROCK SHOX?
From a practical point of view, they are miniature motocross forks that have been scaled down to fit neatly on a mountain bike. Machined-aluminum triple clamps (they are called triple clamps because they clamp on the steerer tube and both fork legs without the benefit of welding) house the chromoly steel fork legs, air-spring internals, hydraulic damping and aluminum sliders.

Rock Shox are not available to the public, but will be by the end of 1989. Retail pricing has not been set, but the MBA test crew believes that the cost will be under $400; whatever the price, we’re willing to pay it! These babies work!

Rock Shox are going to blow the lid off of the critics of mountain bike suspension, because they answer all the questions that scofflaws have been asking.

QUESTION ONE: HOW MUCH TRAVEL DO THEY HAVE?
Rock Shox have only 2 inches of front-wheel travel. That may not seem like much when off-road motorcycles have 12 inches and the often-ballyhooed (but never MBA-tested) Bushido mountain bike had 11 inches. But, 2 inches of travel is more than sufficient to make the off-road bicycle absorb serious blows and still maintain acceptable bicycle geometry.

Remember that when a machine dives and moves under suspension loads, the head angle and bottom bracket height change drastically—12 inches of travel means that the fork rake could end up vertical under hard loads.

QUESTION TWO: DON’T YOU LOSE PEDALING POWER?
No! How can we be so sure? The Rock Shox do not move up and down when you pedal. The forks have an inherent travel “lockout,” which means that the forks only use any of the precious travel when they hit a ditch, stump or rock that demands fork motion. As you pedal—and that includes out-of-the-saddle jamming—the bike operates exactly as a bike with rigid forks would.

QUESTION THREE: WHAT DO THEY WEIGH?
They are one and one-quarter pounds heavier than standard-issue forks. That is an appreciable amount of weight to add to the front of a bicycle, but under hard riding conditions, on fast downhills or through rough washboard sections, that 1 pound melts away. It isn’t possible to take basic chromoly forks and add more parts to them without adding weight. The real question is whether or not the added weight pays its baggage rate in performance; the Rock Shox do!

Riders who believe that the benefits of being able to hit square-edged bumps full speed without endoing aren’t worth the deficit of an extra pound ought to weigh a full water bottle or throw the contents of their tool bag on the scales.

QUESTION FOUR: ARE THEY BETTER THAN PAST SUSPENSION BIKES?
Past efforts to produce suspended mountain bikes have not been met with wild public acclaim, but each was an imaginative effort to solve what everyone admits is a problem for off-road riders. Suspension is a plus for any vehicle attempting to cross rough ground at speeds. Its benefits are well documented. When the wheels remain in contact with the ground, a rider can go faster with less effort and maintain control.

The Moulton ATB has both front and rear suspension that everyone who rides it admires immensely. Moulton uses a leading-link-style front end with a spring, while the rear swingarm is cushioned by a rubber hemisphere. Moulton’s bikes have 2 inches of travel front and rear, but Moulton hasn’t found a ready market in the hard-core mountain bike market because of the bike’s odd multi-tube design and 20-inch wheels.

Dan Hanebrink’s SE Shocker is an aluminum-framed off-road bike that has rear suspension controlled by a rising-rate linkage and gas-charged shock. The MBA test crew spent many hours on an early model of the 4-inch-travel Shocker and felt that its true potential was held back by an over-30-pound chassis weight (the Moulton also weighs over 30 pounds).

Brian Skinner’s Descender was another rear suspension off-road bike that had moderate success several years ago. The Descender used a shock absorber (mounted inside the main triangle) operated by a rocker arm similar to Kawasaki’s Uni-Trak motocross bikes. The Descender was handicapped by its weight, too.

Kestrel introduced the Nitro carbon fiber mountain bike on the trade-show circuit in late 1987. The Nitro had front and rear suspension, and while it was a “studio hit” (a studio hit is something that everyone raves about but nobody buys) on the show circuit, it never made the showroom floor. Interestingly, the Nitro’s suspension components were designed and built by two young designers from Santa Cruz—Keith Bontrager and Paul Turner.

Roger Piper’s Bushido mountain bike was also a studio hit that never was pressed into a record. The Bushido had long-travel suspension front and rear. It claimed a low overall weight, but except for the show circuit, the Bushido has remained both an enigma and a mystery.

Paul Turner’s Rock Shox are the best off-road suspension components ever offered. By putting the travel in the front of the bike, the Rock Shox allows the bike to be more responsive to lateral and vertical forces, which allows the front wheel to stay in contact with the ground. On scary, high-speed downhill corners, keeping the front wheel on the ground can mean the difference between turning the corner or skidding off into a ditch.

QUESTION FIVE: WHAT ABOUT THE BRAKES?
Opponents of front suspension have whined about every aspect of the whole idea. They claimed that suspension would make mounting brakes difficult because the wheel would constantly travel up and down.

How could that problem be solved? Quite easily. Paul Turner mounted the cantilever brake onto the fork sliders so that they would rise and fall in exact correlation to the movement of the wheel. A fork brace, in the form of a chromoly tube, crosses over from brake boss to brake boss to increase lower-leg stiffness. The cable stop (for the housing) is brazed to the fork brace arch. Voila! Perfect brake mounting with no hassles.

QUESTION SIX: DID WE HAVE ANY PROBLEMS?
We were testing prototype units that were (and are) still undergoing development as we rode them, but the design, mounting or performance problems were almost nil. Since the MBA test crew has Bontrager forks mounted on most of our personal bikes, we were able to switch our Rock Shox from bike to bike by simply loosening the Allen bolts and making a five-minute swap. Rock Shox’s triple clamp and Bontrager’s triple clamp are identical. That allowed every tester to ride the Rock Shox on his personal scoot without having to adjust to each other’s iron (we hate to ride the other guys’ bikes).

The problems we did encounter we reported to Paul Turner, and he worked on resolving them. What were they? We couldn’t run an Avocet computer because the fork slider hit the magnet ring. We thought the fork brace was too low to the front tire. We wanted more wheel clearance. Paul made a new bracket. The cantilever bosses were slightly misplaced. Paul fixed that. The black plastic caps fell off of the top of the tubes (exposing the Schrader air valves). Paul is looking for new caps.

The biggest problem was that we didn’t want to give them back to Paul. Since we had one of only a few pairs of Rock Shox, Paul needed our test units back to do more development on them. We couldn’t have been sadder when we slipped them off of our bike and sent them back. Great forks!

QUESTION SEVEN: WHERE CAN YOU GET THEM?
You can’t! And unfortunately, we don’t have ours anymore, either. Rock Shox will be available later this year, and the MBA test crew will give you the full skinny on where to order them, how much they cost and what the latest developments are. Do we believe that these forks are worth riding on? Emphatically yes!