TWF Racing - Forums

No announcement yet.

TWF Racing - Forums

  • Filter
  • Time
  • Show
Clear All
new posts

  • SV650 emulators bouncy

    Hi all, first post here.

    I've got a bounce in the front end of my bike. It's a 2003 SV650N, and I weigh 210 lbs in the shower.

    The shock is from a 2006 ZX14, and in the front I've got sonic 0.95 springs and race tech emulators in the landing gear, err, I mean fork. Haha. I also put new pilot power 3 tires on about 1000 miles ago.

    I drilled and chamfered the existing damper rod holes to 7/16" (no new holes) and brazed the rebound holes closed, per Zoran's method. I also replaced the bushings and seals while I had them apart.

    The emulators have the yellow 64# springs with two turns of preload. For some reason they had all four compression bleed holes open when I got them (directly from race tech), so I soldered two holes closed on each one, as the race tech DVS sheet said two holes.

    I started with PJ Fork Tuner 15 weight, and I've increased it to PJ 20 weight.

    Sag is 35 mm front and 30 rear.

    I took her for a 250 mile ride up to Austin and back over the weekend for the MotoGP race, and she feels pretty good for the most part, but there's an annoying bounce to the front end. It's a pretty quick oscillation on most roads, and it does it over surface bumps small enough that I can't even see all of them. On visibly washboard pavement it turns into a front/rear bucking, especially at low speed (30-40 mph).

    It's definitely worse on acceleration or cruise than it is on deceleration, so it's sensitive to front end load, and it's definitely worse at low speed.

    It was there with the 15 wt, and with all four compression bleed holes open, which is why I soldered two holes on each bumped up the oil weight, and that might have made a marginal improvement, but it's definitely still there.

    Any suggestions?

  • #2
    I have used emulators in my 2009 SV650S as well as used them for a few seasons on my 1999 SV Race bike.

    I started on the street with 10 wt oil, it wasn't until I put 30 wt in which seemed to smooth things out a lot. I also did this on the track bike before switching to a cartridge kit and it helped with the overall feel a lot as well as reducing the pogo or bounce effect.

    Someone else may have some other ideas but that's what worked for me.


    • #3
      Thanks for the reply!

      Did you go so heavy for rebound damping, and just adjust the compression to suit the oil once you got the rebound where you wanted it? Also, did you close the rebound hole on the damping rods?

      I was hoping to avoid really heavy weight oils, because the riding season in central texas goes from 50ish degrees to 105+, and the heavier I go, the less consistent it will be.