• Progressive springs offer a soft initial spring rate for a plush ride while progressively wound design provides increased resistance to bottoming as spring compresses. Improve handling while retaining OEM geometry Made in the U.S.A.! Huge improvement over stock RD400 springs, much more firm for better performance handling. These work great with 10W fork oil, available here on the site. Sold in pairs. Note: This product has additional shipping charges
  • Race Tech Fork Springs -  Yamaha RZ350.  Available in .00kg, .85kg and .90kg spring rates. Recommneded spring rates: Rider weight up to 175lbs - .80kg Rider weight 175-225lbs - .85kg Rider weight 225-275 - .90kg A High Performance Spring has a high stiffness to mass ratio. In other words, it is light weight for a particular rate. This requires the finest materials. And, of course, you want the specific rate you’re paying for. Most manufacturers hold rates within +/-5%, this means a spring marked 5.0 kg/mm could be a 4.75 or even 5.25. (A spring marked 5.0 could be the same rate as one marked 5.4!) Race Tech Springs have extremely accurate rates because we 100% test our springs. Chrome silicon, high stiffness to mass ratio, shot peened, heat treated and pre-set (no sacking). These are the finest springs available, period! Note: This part is not elidgeable for discount or promotion. Note: This part has additonal shipping charges.  
  • Race Tech Gold Valve Fork Emulators for RZ350
    Damping rod forks are notorious for being both too harsh yet too easy to bottom. This is the nature of damping rod fixed orifice forks. In the past all that could be done to improve these forks was change spring rate, oil viscosity or damping hole size, until now. Cartridge Emulators make damping rod style forks perform like well-tuned cartridge forks. These tunable valves sit on top of the damping rods and are held in place by the main springs. This makes them both simple to install and completely tunable for all conditions and rider preferences. Track tests have consistently produce lap times that are 1 or more seconds a lap faster while Cruisers and Gold Wing owners rave at the increased control and ride quality. Note: This part is not elidgeable for discount or promotion.
  • Out of stock
    Yamaha RZ350 (US Versions) Fork Caps with Preload Adjusters CNC Billet Fork Caps with Pre-load Adjusters. Note: These are for the 84/85 US RZ350 (35mm fork tubes) The common misconception with pre load adjusters is that they increase spring tension. What they really do is allow you to adjust sag correctly. With all the suspension mods happening with these bikes it's easy to end up with the wrong sag. Even with the correct spring rate for your weight, you cannot always get the optimal sag without opening up the forks and adding spacers or cutting springs. These give you about 20mm of adjustment, which when combined with the proper spring rate, will allow you to set sag perfectly and adjust it for your weight and riding style. These also have graduation lines on the stems for easy reference when adjusting. Note: Fork tube size is 35mm,  cap thread size is 31mm x 1.5 pitch. Sold in pairs. Kit includes 2 fork caps with pre-load adjusters, o-rings, fork spring discs and installation instructions. Yes you will lose the air forks with these adjusters, but air in forks doesn't work very well as it compresses exponentially. Switching to some of the better after market fork springs and these adjustable pre-load fork caps will really dial in your suspension.
  • Yamaha RZ350/CBR600 Rear Suspension Conversion Bushings. 2 Bronze bushings for lower mounts.
  • Yamaha RZ350/R6 Rear Suspension Conversion Bushings. 4 Bronze bushings for upper / lower mounts. See instructions here: RZ/R6 Shock Conversion