Rivet advice - gearchange selector arm

Again I analysed the issue of the failure to downchange at length, read every post, advice etc. The hook doesnt quite slide over the pin on the selector shaft. A stronger spring may sort, but I found just one post that mentioned dressing the profile of the back of the hook ,I think it was a Ray Shone ,former Iloc chairman, tip, , and of course that is a logical solution, assuming the eccentric adjustment is as good as it can be. It is so simple and once done you can hardly believe that the problem is solved.
 
Nothing replaced internally - did remove the cable to lubricate & had a DAM easy lever fitted for a while - now back to the original.
Always had issues with selecting neutral since I've had the bike, hence the tinkering. Resolved that only to get the problem in not being able to change down from 5th to 4th. Tried my best to sort that with the original parts - will have one last go before fitting all the new stuff.
Why did you remove the DAM lever?
 
Again I analysed the issue of the failure to downchange at length, read every post, advice etc. The hook doesnt quite slide over the pin on the selector shaft. A stronger spring may sort, but I found just one post that mentioned dressing the profile of the back of the hook ,I think it was a Ray Shone ,former Iloc chairman, tip, , and of course that is a logical solution, assuming the eccentric adjustment is as good as it can be. It is so simple and once done you can hardly believe that the problem is solved.
Was there a photo?
 
Read somewhere that the longer lever transmits extra forces to the cover that could cause cracking.
Lubed up the cable and changed back to the original lever, clutch action seems fine to me.
Seems you missed most of your physics classes.

The forces at the pivot and thrust part of the longer lever don't change, only at the very end where the cable connects. No free lunch, remember... the reduced (but now easy-peasy) lever travel also reduces the throw-out at the pressure plate, often causing clutch drag and poor gear/neutral selection, especially at standstill. It's a thin line and can be a pita at the best of times. The only way to increase the pivot or thrust forces that could endanger the sprocket cover is to increase clutch spring pressure.

I very much doubt your gear change issues will be solved with a new selector pawl. The set-up and cure for iffy selection has been done to death on these pages.

piet
 
Seems you missed most of your physics classes.

The forces at the pivot and thrust part of the longer lever don't change, only at the very end where the cable connects. No free lunch, remember... the reduced (but now easy-peasy) lever travel also reduces the throw-out at the pressure plate, often causing clutch drag and poor gear/neutral selection, especially at standstill. It's a thin line and can be a pita at the best of times. The only way to increase the pivot or thrust forces that could endanger the sprocket cover is to increase clutch spring pressure.

I very much doubt your gear change issues will be solved with a new selector pawl. The set-up and cure for iffy selection has been done to death on these pages.

piet
Thanks, no harm in trying though
 
Seems you missed most of your physics classes.

The forces at the pivot and thrust part of the longer lever don't change, only at the very end where the cable connects. No free lunch, remember... the reduced (but now easy-peasy) lever travel also reduces the throw-out at the pressure plate, often causing clutch drag and poor gear/neutral selection, especially at standstill. It's a thin line and can be a pita at the best of times. The only way to increase the pivot or thrust forces that could endanger the sprocket cover is to increase clutch spring pressure.

I very much doubt your gear change issues will be solved with a new selector pawl. The set-up and cure for iffy selection has been done to death on these pages.

piet
This was the post I had in mind - relates to hydraulic clutches though (dohh 😅) Post in thread 'Series 2 Mirage 1200 Clutch Cover removal' https://laverdaforum.com/threads/series-2-mirage-1200-clutch-cover-removal.103045/post-506852
 
So it looks like i have finally cracked it :) and have just returned from a test ride where I was able to gear up,down and even find neutral gear at junctions,Very Very happy (sunny)

Came down to a collection of things really but thanks must first go to everyone who posts and supports with information and their experiences on this forum,it really does help,Carlos your link to SteveioLaverda a great help (goodjob).

So here's what i did,........removed the slack from the gear change spindle selector fork by bending one of the tangs slightly on the doglegged spring, that enabled any movement of the gear shaft to be directly imputed to the linkage and then passed on to the hooked selector arm.

Checked that the eccentric adjuster cam was forward facing,and with the bike in 4th gear adjusted the hooks to give equal movement up and down to the 2 drum selector pins.


Even after doing this and now with a more positive upward selection 1-5 it was still sticking dropping down from 4th - 3rd,I then loosened off the inner gearbox casing and let it find its happy place,also giving it a gentle nudge forwards.

All nipped up and checked with all gears selecting up and down a few times to confirm all was working.

Test ride confirmed a major improvement and a gentlemans box :D

Big thanks to all,now to get in that Jota groove (Lavflag)

Steve
When I first got my Jota I was told there was an issue issue with the gear selection and sure enough on riding it for the first time I was forced to pull up to junctions in 3rd gear as it wouldn't select 2nd,1st and neutral until I came to a complete stop.
Even after multiple successes of going through the gears with the bike on the centre stand and moving the rear wheel by hand I couldn't seem to create it back on the road.
After scouring the gearbox threads on the forum the one which made the most difference was the one which mentioned the doglegged spring and removing the slack out of the gear change selector fork.
Problem solved!

Good luck with yours.
 
a chain rivet press in the vice! what a brilliant idea, I like it a lot, plenty of pressure and very controlable, good call Russ
CLEM
 
Went in again yesterday trying to get a one-shot deal for 1st gear, thought I had it till I noticed a sudden absence of a neutral light. So another 30 minutes flaffing about with the bike tipped over on a left lean. I must have miss alined that horizontal etched mark. Russo where did you get your replacement C hook gadget? Might be time to replace mine as well. My big spring is pretty far from a square orientation as well. For some odd reason that spring has a 3mm gap between its legs on that flat steel plate, it's hard up against the adjusting peg cam gadget but that still allows a fair bit of up and down play on the gear lever, a good 3mm of movement unregulated by that spring.
 
Went in again yesterday trying to get a one-shot deal for 1st gear, thought I had it till I noticed a sudden absence of a neutral light. So another 30 minutes flaffing about with the bike tipped over on a left lean. I must have miss alined that horizontal etched mark. Russo where did you get your replacement C hook gadget? Might be time to replace mine as well. My big spring is pretty far from a square orientation as well. For some odd reason that spring has a 3mm gap between its legs on that flat steel plate, it's hard up against the adjusting peg cam gadget but that still allows a fair bit of up and down play on the gear lever, a good 3mm of movement unregulated by that spring.
Hello Vince, unfortunately still some messing around with my gear change required 😶, my parts were sourced from different suppliers:-
Main gear change plate with splined shaft from DAM in Australia.
Springs, rivet & selector pins from THORNE ENGINEERING in England.
Hook from MOTALIA in England.
Maybe I really should have bought a new eccentric too even though the spare I have shows absolutely no sign of wear. Setting up of this assembly really seems like a dark art that I am still determined to crack.
20240217_142441.jpg
 
Went in again yesterday trying to get a one-shot deal for 1st gear, thought I had it till I noticed a sudden absence of a neutral light. So another 30 minutes flaffing about with the bike tipped over on a left lean. I must have miss alined that horizontal etched mark. Russo where did you get your replacement C hook gadget? Might be time to replace mine as well. My big spring is pretty far from a square orientation as well. For some odd reason that spring has a 3mm gap between its legs on that flat steel plate, it's hard up against the adjusting peg cam gadget but that still allows a fair bit of up and down play on the gear lever, a good 3mm of movement unregulated by that spring.
Vince, you can grind a small groove into the eccentric screw shaft where the spring sits, which reduces the width of the legs of the spring. Take off just enough that the legs make contact. Doesn't alter adjustment but removes slop, which is where a lot of problems arise (because the hook won't fully travel to drop over the pins in the selector 'drum').
 
If you look at the pic above that rectangular bit just to the left of the eccentric is what the spring doesn't touch on mine, there is approximately 3mm of clearance that produces more free play than I like in my gear lever. So you're saying Q grinding a grove where the spring touches the eccentric deep enough so the spring contacts both would help and not hinder? I guess laying a bead of weld on the rectangular section and building it up a bit would have the same effect. My spring tends to lay over on its side a bit as well. Job for a Swish clockmaker. Russo thanks I will look into those bits.
 
If you look at the pic above that rectangular bit just to the left of the eccentric is what the spring doesn't touch on mine, there is approximately 3mm of clearance that produces more free play than I like in my gear lever. So you're saying Q grinding a grove where the spring touches the eccentric deep enough so the spring contacts both would help and not hinder? I guess laying a bead of weld on the rectangular section and building it up a bit would have the same effect. My spring tends to lay over on its side a bit as well. Job for a Swish clockmaker. Russo thanks I will look into those bits.
Change the spring?
Paul
 
four points of contact are required without gaps.
bend the spring to fullfill that and then set the adjustment.
Did so on my bike and everything is great.
 

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