F-Pro Microbearing Detent Arm
Hybrid Ceramic microbearing
or
Steel microbearing

Tortured by false neutrals and missed shifts?  Gearboxes last only 5-10 races?

Part of the shifting problem is that there is just too much friction in the shift mechanism. Factory Pro produces a detent arm with a slick rotating ball bearing instead of a stock scratchy riveted disc.

Reduce ugly and unattractive friction for virtually perfect shifting.
Make your transmission "snick" into gear and keep itself in gear.

Reducing the rotating friction allows the shift mechanism to rotate quicker and get the gear dogs over quicker and fully engaged - so they stay engaged under part throttle (as in when you are 15ft in the air over a set of triples).

The F-Pro arm and the recalibrated, heat treated F-Pro spring are the solution in helping the Suzuki develop bulletproof shifting.

The tough, steel raced, Hybrid Ceramic Microbearing is the ultimate in friction reduction for this use. The STD Steel arm is 98% as good as the Hybrid  (and less expensive) - and both are way slicker than the stock riveted roller.

 Installation: The detent arm and shift spring sit right under the clutch basket - so, it's just R&R the clutch basket to install.  About an hour to install.

Marc "No missed shifts" Salvisberg
Factory Pro Tuning

415 883-5620

marc@factorypro.com

    Works great!  It was easy to install.    S. Berger (rmz250)

     It's freggin awesome. Night and day difference.. I raced this weekend.. 4 motos and never a miss shift or false neutral   Dec 2013

  I had the new detent spring installed and also went with the Factory Pro arm - it doesn't have any slop/play like the stock unit does. Rode it today for the first time and it shifts like my 450 now. Not a single missed shift. That's the best spent mod I may have ever done,    Dec 2013

   I initially thought the Factory Pro arm and spring was very pricey, but what I learned, this is all these guys do. They have a niche and they do it well.
What I can say is this was one of the better mods I've done to a bike. My shifting is so predictable now. TDC51  Dec 2013

Feedback:
marc@factorypro.com

If the shift shaft fingers aren't centered on the shift shaft, Factory Pro has the fix.

To get equally good up and down shifting - you need to control how the shift shaft grabs the detent star posts.

It's a special offset "centering" stud, adjustable by almost 1mm.
More experienced mechanics will recall when almost all transmissions were equipped with parts like these. That allowed the engine builder to set the shift shaft to exactly in the center for the best possible shift performance.

Install the stud with enough threads exposed for the locknut.
Turn stud till shift shaft "fingers" are centered on detent STAR pins.
Tighten down the locknut.
Recheck indexing.

This is NOT the right picture.
The rmz has a different setup to turn the shift drum - but - it still uses "2 things" to push the shift drum around. One side for upshift and the other side for downshift. Ideally, the 2 shift shaft arm pusher "things" should be centered on the thing (or things, as in the above picture). On the rmz, you'd center the 2 spring loaded "gear shift pawls" in the notches in the shift star.
That makes equal shift lever travel in both upshifts and downshifts - improving shifting.