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NC30 Race-Tech Fork Specifications
(for VFR400RL-N models)

Last time we checked, Race-Tech's extensive Web site did not list specifications for the NC30 (and it only listed CBR400RRL-N specs, i.e., those with damping rod fork design—these specs may be useful to owners of "K" model VFR400Rs, however). Cliff Piper of Piper Performance Racing in Arizona, an authorized Race-Tech Center, calculated the following specifications for use with Race-Tech straight-rate springs and a rider weighing 190lbs. Your mileage may vary considerably...

Race-Tech Spring Rate Chart:

(left side values are in kg/mm)
Lbs. (combined bike and rider)

Spring Rate Calculation:

The VFR400RL-N's weight is:

  • Dry weight is 175kg (385.8 lbs.)


  • Curb weight is 192kg (423.3 lbs.)


  • Racing weight is (typically) 180kg (400 lbs.)

    • For a street bike, a combined bike and rider weight of approximately 620 lbs would indicate that 0.85kg/mm fork springs (Race-Tech pn. FRSP S3534-85) should be used; for a race bike, 0.90kg/mm fork springs would be a better choice. The Race-Tech fork springs are considerably shorter than the NC30's stock springs; NC30 forks are shorter than most bikes' forks. Accordingly, in order to set the initial sag, just 3-4 steel fork spring washers on top of the springs in each fork may suffice.

    Miscellaneous:

  • Fork oil: 460cc of 5wt in each leg [390cc specified in the Honda Manual, but it's better to measure it, anyway: 122mm (4.8 in.) from the top of the fork tube]


  • Preload spacers: [Make to measure using the Race-Tech procedure for setting initial sag]


  • Initial rebound setting: 8 clicks out [this is 1/3 of the way out]

    • Spring Rate Conversion Factors:

  • ft/in (0.0178584) = kg/mm
  • kg/mm (55.996951) = ft/in

    • Other Shocking Notes:

  • NC30 Penske shock length: 12.3in (approx. 315mm) (to mid-point of adjustment)
  • NC30 Penske shock spring rate: 850lb/in (for rider 200lbs w/gear) (but a 900lb/in spring might be a better choice)
  • NC30 Penske shock spring dimensions: 6in free length; 2in I.D.

    • VSource.org Home Copyright © VSource.org 1999-2005 [Sources: Race-Tech, Piper Performance Racing, Phoenix, AZ (602) 587-7708 and the Honda NC30 Service Manual]