2005 Suzuki GSX-R750 Race Tech Fork Mods for Heavier Riders | Mod of the Month

From the November, 2011 issue of Super Streetbike

By Chris Riesenberg, Justin Fivella

Photography by Josh Geraurd

Riders modify their suspension for many reasons, whether it’s in pursuit of better ETs at the drag strip, quicker lap times around a race track or in search of a supple ride. Sometimes it’s necessary for a physical reason—weight.

In the past we’ve covered several projects that took a stock-height bike and lowered it to better fit a person of shorter stature, but what about those individuals who simply outweigh the stock suspenders? What are they to do when their sportbike wallows and sags under the load, not because the parts are worn out, but simply because their weight is outside the limits of the stock suspension? Modify it, of course.

When a local rider brought his 2005 GSX-R750 by our office complaining of suspension problems, it only took one glimpse at his size for us to immediately understand why. Standing a few notches over six feet tall and tipping the scales on the north side of 240 pounds meant he was too large for the stock suspension setup. Even with the settings tightened the forks would bottom while on the brakes (and we’re not talking race track braking, but rather a semi-aggressive street stop). A stock sportbike suspension setup is designed for a 150-170 pound rider, not someone who’s well over 200.

Since the GSX-R750 had amassed nearly 30K miles we decided to start with a full fork revamp. Along with new fork seals, dust seals and Race Tech oil, the crew at RT also added a Gold Valve rebound valve along with a Gold Valve compression valve. These golden goodies not only offer more compliance over slow-speed bumps, but they’ll eat up the bigger stuff as well. While the techs at RT were at it, they also added some burly 38x36x250 1.0kg springs and even crosshatched the inner tubes to ensure the oil would adhere to them long enough for proper damping. Since oil will run down a smooth tube faster than a rough one, crosshatching the surface makes the oil hang around a little longer.

Although you can buy the parts and do the work yourselves, we thought it best to leave it to the pros, so we sent the forks to Race Tech.

Follow along as the suspension gurus show us how it’s done, and check back next issue as we address the sagging rear shock and finish up with a full ride report. ssb