gear selection

stu · Jul 19, 2018

Hi

I replaced the gearbox outer cover with a new one (don't ask) and am struggling to set up the correct pedal operation. At rest the gear pedal doesn't snap back into centreline and selection is ratchety. At speed, struggling to find neutral and first with the foot though I can pull the lever back up into first by hand. Once engaged all gears pull fine and with outer cover off all gears select cleanly.
I suspect the pawl spring and have set this several times with slightly different bends -offering outer cover to the inner with gearchange ratchet set in second gear. The outer cover functions fine off the bike with the return spring / stop plate etc all set correctly. The pawl spring is set as recommended with crank to bottom and legs running 90deg across the pawl with a bawhair gap either side. Any ideas where to look ?

Stu

concours · Jul 19, 2018

Parts quality?

We need pictures
Good one

stu · Jul 19, 2018

Thanks Concours, I'm UK and order from AN or RGM - no issues with parts quality so far . .

I've put a new return spring in the cover (though the old seemed fine) and slathered new o rings, bushes, everything in oil - seems a bit more positive with the pedal springing back better - road test tonight after tea will see

stu · Jul 19, 2018

gears are back ! Can only think the return spring was a bit tired and struggling with the friction of new snug fitting seals ??

htown16 · Jul 19, 2018

The return spring can be a bit touchy. It needs to equal space on both sides of the gearshift pawl when the pawl is centered. That assumes you put the spring on the right way round as it is easy to reverse. See the section on the outer cover towards the end of this article.
http://www.oldbritts.com/gearbox_a.html

stu · Jul 20, 2018

htown16 said:
The return spring can be a bit touchy. It needs to equal space on both sides of the gearshift pawl when the pawl is centered. That assumes you put the spring on the right way round as it is easy to reverse. See the section on the outer cover towards the end of this article.
http://www.oldbritts.com/gearbox_a.html

That's a good article - thanks. The return spring I replaced for new was the one between the stop plate and the cover - part 10 here ;
https://andover-norton.co.uk/en/shop-drawing/208/gearbox-outer-cover-kickstart-gearshift-lever

Two or three variables here but I think this might've been the issue - gears changing fine now

htown16 · Jul 20, 2018

Yes that is the one that causes the problem. If often has to be tweaked to get things to work right. You must have hit on the right position.

dave M · Jul 21, 2018

The bracket that holds the large return spring underneath the shifting mechanism can foul the tang that engages with this spring. The two bolts that hold it to the outer cover do not automatically centre the bracket. I always bolt the bracket on finger tight, put the shifting mechanism in place without the spring and make sure it can freely travel throughout it’s intended arc and only the tighten the two mounting bolts. If the tang hits the bracket the gearshift mechanism may not return to the rest position, however if you persevere it sometimes rubs enough material away to start working correctly.