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How do I know if the pawl spring is broken?


Frenchie

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for the cover... others have described well. once the dots are aligned, look under one of the cogs (the one over the neutral switch) and you'll find a small indent (about 1/8" concave) and turn the cogs till the neutral switch plunger pops into the indent. thats neutral.

 

for the gearbox, I just (as others have said) moved the selectors around (very scientific) until the rear wheel turns freely. The selector ends facing the cover form a sort of rectangle pattern as I recall.

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Thank you so much for the helpful replies.  I have managed to get the spring replaced.  The arm looks slightly different to other pics I have see as there is a specific mounting point on the arm where the spring seats, instead of just bent around the arm.  I'm presuming this was a later design.

 

To address some of the replies - the dots align on the selector wheel when the gearbox is in first.  I also noted that both of the adjusters can be adjusted externally, at least on my bike.  Others have commented that the smaller adjuster can only be accessed when the selector plate is removed.

 

I just did a test ride and the gears seem to select well, and neutral is easy to find.  However, I noticed that I had a few false neutrals in 4th & 5th.  I also noticed that that the false neutrals only occurred when using the clutch to shift up, when I shifted without the clutch, it engaged perfectly.

 

Can anyone suggest which of the adjusters might be affecting this? I didn't change the large one, but inadvertently changed the smaller one, so I had to reset it by testing the preselectors.  They seemed to work fine at that stage, but the road test gave intermittent false neutrals..

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Here is a link to LuckyPhil's definitive tutorial on "V11 Shift Improvement" . . .

 

http://www.v11lemans.com/forums/index.php?showtopic=19547

 

I would definitely do this. You can't do it with the cover on the gearbox. I don't think you will ever get perfect shifting otherwise, like my bike has now.

 

I think the two most important things to address are the overtravel of the shift mechanism and the adjustment of the small eccentric, which prevents over-rotation of the selector wheels. 

 

Phil welded both sides of the slot in the shifter arm but I found you can weld just one side, then set the eccentric to perfection on the non-welded side and don't touch it again. Then file the welded side a little at a time for perfect travel on that side.

 

I adjusted the small eccentric so the shift claw just touches the pin at full travel. Don't get it too tight or the shift mechanism will stick, but you don't really want any clearance to speak of there. This keeps the inertia of the selector wheels from continuing to rotate the wheels past the detent, into a false neutral. I believe that's what causes the false neutrals.

 

And if you smooth the ramps on the shift claw, don't take off much material, because those ramps are critical to stop the over-rotation.

 

Just do it!  :grin:

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Thanks all again for the inputs. 

Before I start welding, polishing, filing, straightening (all of which I'm happy to do), I haven't yet figured out how I know if I have made the right changes or improvements before reassembling and riding it again.

 

I have the selector on the bench - see this short video of it being operated just now .  You can see from the video that the selectors (at least to my eye) seems to be working fine.  So can anyone identify what specifically I am doing wrong?  

  • Are there specific clearances for the small eccentric adjuster? 
  • Where do I measure the 0.7mm clearance on the large adjuster? 
  • Since my issue is only on shifting up the box, which of the adjusters affect this? 
  • Is it possible to say which direction that adjustor should be rotated to address this specific issue?
  • Lastly how do I remove the plate which ties the two selector wheels together?

 

Thanks

- Paul

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Update!
I’ve straightened the arm which had a bend and twist in it and polished all components and reassembled.

On the bench, the selector seems to work fine (just as before), but I have not figured out how to position the eccentric adjusters. At which stage of travel does the clearance need to be measured?

I’ve read and re-read Luck Phil’s post several times but I can’t figure out where to take these measurements and at what stage of travel.  If it’s not necessarily a question of measuring the clearance, what other ways are there to set up the eccentric adjustments when it’s on the bench.
Thanks
Paul

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I wish I could just swing by your house and point at things, it would be so much easier. Not likely, though.

 

You want to do the big eccentric before the small one. The problem with the big eccentric is that the "window" in the shift shaft is too wide and no matter where you set the eccentric, the travel is too much in one or both directions. If you do a shift and hold the shifter against the eccentric pin at full travel, and play with the selector wheel you can see that the shift arm is either rotating the wheel past the detent a bit or not quite all the way to the detent. 

 

You want the hook on the arm to rotate the wheel exactly to the detent position when the big eccentric pin stops the travel. You need to narrow the window in the shift shaft so you can get the travel perfect in both directions, hence the welding. Set it up perfect in one direction, then leave the eccentric alone, add weld to the other side of the window and file until perfect in the other direction.

 

You can see that the small eccentric can be positioned 2 ways, kind of to the left or right as you are looking straight at it. I don't remember which is correct. The idea is that at full travel of the shift mechanism in either direction, the shift arm will just about or barely contact the pin. That causes the pin in the selector wheel, contacting the ramp on the shift arm, to be unable to push the arm up, so the selector wheel is locked in position at full shift travel, and unable to over-rotate into a false neutral. Let me know if that doesn't make sense, I don't know if I'm making it clear.

 

If you try the small eccentric to the left and right it should be obvious which is correct, because the shift arm will be equally close the eccentric pin at both ends of travel. I think the .7mm is meant for the small eccentric, but I think the less clearance the better. Mine works great at 0, just make sure it doesn't stick/jam.

 

This stuff is hard on the brain to describe!  :wacko:

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CoreyTrevor, Well if you ever come to Ireland you would be most welcome to stay at our house !

 

Your explanation is very helpful, though I’ve packed in for the night, I’ll have a go at it tomorrow.

 

I came to the same conclusion regarding the small eccentric clearance as having a Gap didn’t seem to make any sense apart from perhaps allowing for heat expansion.

 

Can I use a stick inverter welder to weld on a tab, or should I braise on a tab?

 

Sorry for all the questions, but I’m very grateful for your help!

 

Paul

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I think I broke a pawl spring on my LeMans today. I was able to sneak in a few shifts after braking (which throws the arm forward). Fortunately, it happened close to home. One I got it in 3rd, I left it there and tried to time the remaining stops so I could roll through - but it can be coaxed to start in 3rd from a standstill.

 

Oh joy... I get to smell gear oil tonight or tomorrow.

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Scud, it may be time to investigate the Japanese coil spring mod for real. Didn't footgoose do it?

 

I was thinking very much about that on the way home... in between the curse words echoing in my helmet.

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Scud, it may be time to investigate the Japanese coil spring mod for real. Didn't footgoose do it?

 

I was thinking very much about that on the way home... in between the curse words echoing in my helmet.

 

If you need something machined, just say the word. It's time we fixed this thing once and for all.

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