GSAP working on up shift but not on the down shift? Read on.

I was having problems with my GSAP on the downshift on my 2005 RS. Whilst touring Scotland, in fact a little before that, the GSAP was okay on the up shift, but on the down shift was very reluctant and 'stiff' and whilst on the tour it just wouldn't down shift unless I used the clutch, it felt like it was binding up, the lever just wouldn't move. As I say using the clutch on the down shift and the change was fine.

On investigating I found the lateral movement, left to right, in the shift lever to be over 10mm (1/2 inch) at the rubber boot end. Having discovered this I change the direction I was pushing down on the lever i.e. instead of just pushing down, I kind of push the lever in towards the engine whilst then pushing down, this helped and I was able with some finessing to get GSAP down shifts - but it wasn't the easiest of things to, so stuck with the clutch to down shift on the tour.

When I got home, I took the lever off the bike and on the outside (the big Torx drive side) I made a simple washer out of an old plastic milk bottle, this still allowed the lever to pivot but reduced the lateral movement to very little. The GSAP down shift is now back to how I remember, no binding or stiffness and no 'special foot technique', push down and it activates.

I took a look at the parts involved on the microfiche and the prices for the lever and the pivot 'bolt' and for now I'm happy with my bodge :-)

Jason

I got hold of a lever and the boss it pivots on from a breakers for under £50, and can confirm that a worn lever / pivot stops the downshift using GSAP, the 'new' lever and pivot work faultlessly. So at least on my bike and the way I activate the down shift having too much lateral movement in the lever means it binds up and wont downshift, but as reported originally, will still downshift when using the clutch.

The original lever wear has occurred at about 33,000 miles.

I'm considering approaching a precision engineering workshop and finding out how much it will cost to put a phosphor bronze bush (or similar material) on the old pivot and a corresponding one inside the old lever, as the 'new' one is just as likely to wear out in 3 to 4 years.

Here's a photo of the worn (scored) pivot boss and the inside of the lever's bushing, so it's clearer what I'm talking about
20210712_175503.jpg - Bild entfernt (keine Rechte)

Jason.

Interesting.

I haven't found a problem in changing gear. The Quickshift always needs a good kick.

But having passed 32,000 miles I'll take a closer look at the lever.

I guess I use the clutch for more than half my gear changes. Only use the quick shift when I'm "getting it on a bit".

At lower speeds (including gentler acceleration), I find short shifting up with the clutch gives a much smoother ride.

Zitat von Boxerboy55 im Beitrag #3

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Interesting.

I haven't found a problem in changing gear. The Quickshift always needs a good kick.

But having passed 32,000 miles I'll take a closer look at the lever.

I guess I use the clutch for more than half my gear changes. Only use the quick shift when I'm "getting it on a bit".

At lower speeds (including gentler acceleration), I find short shifting up with the clutch gives a much smoother ride.

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