Front Suspension Upgrades
Posted: Thu Feb 16, 2012 2:11 am
One of my goals with my '97 Sport Tourer project is to improve the bike's handling for these local canyon roads. The stock fork feels sluggish and too soft. Reading the Seca II Challenge article, they upgraded the stock fork by modifying the damper rod, running a lower fork oil level, installing Progressive springs, adding PVC preload spacers and using a thicker (15W/20) fork oil. Here's the specific excerpt taken from the article:
The other option I see is to modify the forks with a set of Racetech cartridge emulators. I believe the set spec'd for the FZR600 could be used on the Seca II. Thoughts?
To replicate this for the '97, I can purchase Seca II Progressive Springs and heavier weight (15W) fork oil and can manufacture the spacers. My question is, does anyone have any information on the modifications to the damper rod and on determining proper fork oil level when modifying the damper rod?Upgrading the suspension was the first step. Though very compliant for around-town riding, the 38mm conventional fork and cantilevered single shock are too softly sprung and too lightly damped for back road blasting. For an affordable solution, we took the bike to Progressive Suspension in Hesperia, California. Progressive modified the fork's damper rods, set the oil level at 6 inches from the top of the fork tubes (measured with the fork collapsed and the springs removed; stock is 4.4 inches) using Silkolene 10-wt fork oil, and fitted a pair of the company's FZR600 replacement springs. Compared to the stock setup the fork was significantly firmer, but still rebounded too quickly. Replacing the 10-weight oil with the same amount of 15/20-wt Bel-Ray made a noticeable improvement. Preloading the springs with 1 11/16" lengths of PVC pipe resulted in the proper 1 inch of sag.
The other option I see is to modify the forks with a set of Racetech cartridge emulators. I believe the set spec'd for the FZR600 could be used on the Seca II. Thoughts?