The shifting lever on my machine is in a position that requires my foot to be raised higher than is normal for me to shift into a higher gear. Once in a while I don’t lift the lever up enough and the gear engagement cogs don’t get fully meshed. When that happens, it pops out of gear while under load. Very bad. So far no serious damage has happened (I think/hope).
The most likely solution is to move the lever one notch down on the shaft splines, but the result is a 25mm drop in the lever. I tried that quite some time back but it caused too much toe contact with the lever. Never gave the issue much more serious thought until today while doing some cleaning.
It came to me that if I could not lower the shift arm at the splines to the correct height, I could increase the diameter of the shift arm pedal rubber to effectively lower the contact point to my foot. Happened to have some ¾”ID clear tubing handy so I cut off 30mm length, slit it lengthwise, wrapped it around the shift arm pad then zip tied it on. This dropped the contact point about 4mm. I took her out for a spin and what a difference that made! Now when I go for a upshift, it solidly goes into a full engagement without having to make extra toe lift effort.
Now that I know this setup works, I’m going to move the zip tie ratchets forward to eliminate contact with my shoe.
If a person needed more drop of the lever arm, some thicker walled radiator type hose would probably work.
I am sure that some others may have the same issue. Hope this helps.