SHFT-EVO-HON-91
$199.95
(replaces 24315-MW0-791 stock vfr star)
Trans Detent Arm Kit

EVO Shift STAR Kit available for the vfr800

As a professional engine builder (but less and less these days, marc), I've done most everything you can do to a set of gears, and shafts.

• A great (read as 5 to 10 hours of labor) gearbox job generally includes:
   

  • Shimming to minimize lateral play on the gears. (to builder's judgment)

  • Shimming to move each fixed gear closer to it's sliding mate (but not too close) (to builder's judgment)

  • Shimming shafts to move the assembly closer to an optimum position. (to builder's judgment)

  • Using a surface grinder to make your own custom thickness shims.

  • Making sure that you place the "rounded" side of the circlips against any shim or gear

    • That puts the "sharp" edge of the circlip nicely in the circlip retaining groove on the transmission shaft so it doesn't "ramp out" under side loading..

  • Checking and adjusting shift mechanism "fingers" on the shift star "pins". (to builder's judgment)

  • Checking, replacing gears with worn engagement dogs and slots - or undercutting worn engagement dogs.

    • I tend to try to use as little angle on the undercut, as the more undercut angle, the more you have to let off the power to get the gears to separate - important when not using a "quickshifter" or "air shifter".

  • Deburring of most gears, most shafts, the shift drum and the shift forks

    • A commercial facility, such as Supertech, owned by the iconic Dennis Zickrick, in Colorado, does metal finishing and low friction coatings.

  • I don't recommend cryogenically treating powdered metal gears, like most Japanese type gears are - I don't feel it's a good use of the process. I know that I'll get some flack on that. I'm not saying that "cryo" is bad, as I do use it at times for pistons, springs, knives, unfinished gun barrels... just not powdered metal gears or large finished machined castings.
     

• Additionally, separate from the gears and shafts, there's the shift mechanism (shift shaft, selector device, shift fingers, detent arm and spring, detent star)
   

  • Checking straightness of shift shaft (sometimes they get bent on the left, shift linkage / rear set side)

  • Polishing sliding parts in the shift mechanism (to decrease friction of shift drum rotation - and "quicker is better")

  • Reducing friction of the detent arm (arm needs a bearing - which we make as a model requires and "quicker is better")

  • optimizing detent arm spring pressure (if the spring pressure should be changed, we make - and "quicker is better")

  • optimizing detent ramps (if the ramps aren't right, we make replacement "stars" - making it "quicker")
     

• Adding an EVO Shift STAR kit - In general, if the gearbox is setup "alright" (I would say that most stock, original, undamaged transmissiona are "alright"), that just adding the EVO Shift STAR kit is going to be 80% to 90% of what is theoretically possible in improving shifting quickness, reducing missed shifts, decreasing rider effort and protecting the shift forks and gear engagement dogs from damage caused by missed shifts.
   

• How do you know that a transmission is shifting quicker and more reliably?

  • You can feel it when riding.

    • Even when hand shifting on the bench, it's easier to get out of gear and "snicks" into gear, rather than "clunks" into gear (yes, most Kaws won't shift into 2nd unless the output shaft is spinning :-)

  • You notice that you only have time to slightly "twitch" the throttle off a teeny bit between shifts and hardly have time to pull the clutch lever even a little before the bike's already in the next gear.

  • You "try" to miss a shift on bench or riding and almost can't.

  • Your "quickshifter" equipped bike shifts clunkily after an EVO Shift STAR kit install and you have to decrease "shift kill time" by 15 to 20ms to accommodate the EVO STAR's quicker shifting.

    • That 15 to 20ms is now converted to "engine power" time, rather than "engine kill" time. That will improve power delivery time on a racetrack and at the drags.

    • Funny story - an AMA team called up and said the bike's shifted awfully clunky after the Shift STAR - I was mystified and in talking, we couldn't figure out why the riders claimed the clunkiness - as in the pits, it was def. quicker - and didn't even think to ask about whether they were using a quickshifter.
      They called up later and said that they figured out that the "quickshifter" was now killing the power too long and it was perfect when they decreased the shift kill time.

      • BTW - for roadracing, a perfect QS system will have several factors to program. Should still be pretty easy to sort out - and there's nothing commercially available as or Feb 2009, and that includes the guy who supposedly built his own Suzuki ecu, (well, he did make the box at least - the ECU seemed to be a repackaged EFI Technologies ECU according to the software) on the market that's "right" for roadracing, though most all are are fine for drag racing and  "alright" for roadracing.

Adding the EVO Shift STAR kit makes shifting so sweet that you'll want to ride just so you can slip the bike into each gear with silky precision. The Marc Salvisberg designed Shift STAR has optimized compound arcs, peak heights and valley depths that almost do the impossible - it's easier to get out of gear and shifts quicker into the next gear -
The normal, original lag in shift completion rate is what makes the transmission feel "clunky" around town.

Make shifting MUCH quicker and virtually eliminate missed shifts. Helps address missed shifts caused by poor shift detent "star" profile.

The kit includes the new Factory Pro Shift STAR and the Factory Pro detent arm and spring, as described below.

User's comments

Most Excellent user (rlkoster) install webpage - click here

FI-BMC-18704S    $89.95
Factory Pro BMC Street Filter

Factory Pro / BMC Street air filter

Cleanable cotton gauze type filter.

FI recalibration is not required, but even a stock bike will perform better if the FI is remapped.

"This project is a collaboration between Brandon Monnig and I. Brandon installed a Factory Shift kit in his '93 VFR and photographed his install. I volunteered to write-up this article based on my install............"

http://www.one-ring.net/strider/stable/shiftkit.html