Route cause of jumping out of sixth?

[babble]

Does anybody know exactly what causes some bikes to do this (aside from the ones where a sticking pedal mechanism was the culprit).

Is there a fix? I seem to recall welding the selector drum on an MZ to fix it's 2nd gear slippage.

(I've now got an XT600 with a slipping clutch and slipping 2nd gear, and a GS with slipping clutch and slipping 6th gear.... doh!)

Cheers,

David.

 

[Burra boy]

No idea. My 1150 has been doing it off and on since new - now has 120 000 kms on it and the gearbox has yet to fall out onto the road . I have discovered that it seems to be caused by a gentle (lazy?) upshift from 5th and a steady throttle after that, so I've developed the habit of rocking the throttle closed slightly after shifting, which seems to prevent the sudden downchange to 5th...

 

[John Armstrong]

I was told that changing the gearbox oil every 6000 miles instead of the scheduled 12000 helped prevent it.

 

[PIGGLET]

I've just changed to synthetic gear oil and found a big difference. It didn't jump out of sixth but when hot would often just not go in ala burra boy.
My bikes done 13k and was only serviced 2k ago by a dealer. The oil wasn't particularly dirty when i drained it but it's made it lots smoother and put the £1000 replacement gearbox nightmares to bed

 

[Bagpuss]

Gearbox blues...

Just in the process of gearbox replacement myself....

I have drained the oil out of the poorly gearbox and was surprised to see the oil looking more like silver metalic paint!!! I am sure this is not the proper colour... nor is it healthy that a lump of something poured out of the gearbox with the draining oil!!!

Anyway, now up to my eyes and ears in bits and i still haven't lifted the subframe out of the way.

These feckin GS's aren't half over engineered! My old escort was far less complicated!

Anyway, hopefully will be back on the road this weekend