Shifting trouble

[Dan M]

I ordered a shift pawl spring from Bonnie with the idea I'd catch it before it breaks. Changed it today, very straightforward job. After it was all together shifting the bike by hand with the engine off it felt like the shifter wasn't returning on the up shift with the same spring pressure as on the downshift. I took it out for a short ride (25 degrees here today) and I had to wiggle the shifter to let it catch the next gear on the up shift. Downshifts were fine. So with a sigh I took it back apart and found that indeed, when you move the ratchet arm against the selector on the up shift it does not return readily. (wiggling the shifter was helping the spring pull the ratchet arm back to center) I removed the spring and matched it up with the old one and it is not quite the same angle. Only off by a few degrees, but it is causing more pressure on the arm causing it to drag against the selector rollers while returning to the center position. Removing the ratchet arm from the assembly lets the selector shaft spring back to center from either direction with the same force. With the ratchet arm and spring installed there is substantially more return force from the downshift direction My first thought is to reshape this spring for less tension on the ratchet arm. I installed the old spring and the action is similar, not correct in my eyes but not as bad. I have the exploded view from the parts manual, and everything appears to be installed correctly. When the ratchet arm is in the center position it is pretty well centered over the selector rollers so I doubt adjusting the eccentric under the acorn nut would help. One more thing, I had some up shift problems last summer that were completely eliminated with the change to Redline shockproof lube. Seeing what is happening here makes me think this arm was dragging on the return to center back then. Any thoughts?

[bigbikerrick]

I ordered a shift pawl spring from Bonnie with the idea I'd catch it before it breaks. Changed it today, very straightforward job. After it was all together shifting the bike by hand with the engine off it felt like the shifter wasn't returning on the up shift with the same spring pressure as on the downshift. I took it out for a short ride (25 degrees here today) and I had to wiggle the shifter to let it catch the next gear on the up shift. Downshifts were fine. So with a sigh I took it back apart and found that indeed, when you move the ratchet arm against the selector on the up shift it does not return readily. (wiggling the shifter was helping the spring pull the ratchet arm back to center) I removed the spring and matched it up with the old one and it is not quite the same angle.  Only off by a few degrees, but it is causing more pressure on the arm causing it to drag against the selector rollers while returning to the center position.  Removing the ratchet arm from the assembly lets the selector shaft spring back to center from either direction with the same force. With the ratchet arm and spring installed there is substantially more return force from the downshift direction My first thought is to reshape this spring for less tension on the ratchet arm. I installed the old spring and the action is similar, not correct in my eyes but not as bad. I have the exploded view from the parts manual, and everything appears to be installed correctly. When the ratchet arm is in the center position it is pretty well centered over the selector rollers so I doubt adjusting the eccentric under the acorn nut would help. One more thing, I had some up shift problems last summer that were completely eliminated with the change to Redline shockproof lube. Seeing what is happening here makes me think this arm was dragging on the return to center back then.  Any thoughts?

80258[/snapback]

Dan, by any chance did you measure the diameter of the "bobbin" the spring is wound around? remember ,some were found to be 1 0r 2 mm too large in diameter. I think 16 mm instead of 15. I noticed that the spring I bought from bonnie seems to have a smaller hole in the center of the coil, and one winding of the coil is not perfectly centered. Im thinking maybe its binding on thr bobbin,or whatever you call that part. some folks filed that round part down some, Im just "shooting from the hip " here, but its just an idea....

[dlaing]

. When the ratchet arm is in the center position it is pretty well centered over the selector rollers so I doubt adjusting the eccentric under the acorn nut would help.

80258[/snapback]

I don't think that being centered over the selector rollers indicates that the eccentric adjuster is set properly

You want to be right in between the two obvious failure points, where it either won't upshift at all or it won't downshift at all.

Note the weight of the selector pedal also has some effect and ideally would be counterbalanced...

 

My fabulous instructions for adjusting it with the case closed are here

http://www.v11lemans.com/forums/index.php?...topic=6118&st=0

Check it out. BelfastGuzzi cooks up some tasty pasta, and I critique it.

 

If the case is open, you should have no trouble adjusting it...if you can loosen the aduster.

this thread also may be useful:

http://www.v11lemans.com/forums/index.php?showtopic=5866&hl=

 

If it is not the adjuster, I have no idea, I have never replaced the spring.

[Dan M]

I don't think that being centered over the selector rollers indicates that the eccentric adjuster is set properly

You want to be right in between the two obvious failure points, where it either won't upshift at all or it won't downshift at all.

Note the weight of the selector pedal also has some effect and ideally would be counterbalanced...

 

My fabulous instructions for adjusting it with the case closed are here

http://www.v11lemans.com/forums/index.php?...topic=6118&st=0

Check it out. BelfastGuzzi cooks up some tasty pasta, and I critique it. 

 

If the case is open, you should have no trouble adjusting it...if you can loosen the aduster.

this thread also may be useful:

http://www.v11lemans.com/forums/index.php?showtopic=5866&hl=

 

If it is not the adjuster, I have no idea, I have never replaced the spring.

80286[/snapback]

 

Thanks for the replys. After reshaping the ratchet spring for far less tension the action is perfect. I loosensd the eccentric and played with it watching the position of the ratchet against the selector rollers. You can get a good feel for the position in the middle gears, I found that if you position the ratchet very slightly "low" (maybe 1/64 or less") giving you more play on the upshift side of center the return action in both directions is more positive. Also while I had it apart I polished the "ramps" on the ratchet arm where they slide on the selector rollers. When operating by hand it feels much more smooth, almost, dare I say it, Japanese

[dlaing]

You can get a good feel for the position in the middle gears, I found that if you position the ratchet very slightly "low" (maybe 1/64 or less") giving you more play on the upshift side of center the return action in both directions is more positive. Also while I had it apart I polished the "ramps" on the ratchet arm where they slide on the selector rollers.

80329[/snapback]

Very interesting!

Now if we could only get you to cook up some pasta ala BFG (meaning photos with diagrams would have been great...or )

[Dan M]

Very interesting!

Now if we could only get you to cook up some pasta ala BFG  (meaning photos with diagrams would have been great...or    )

80335[/snapback]

 

Can't right now, I'll be out of town tomorrow thorugh Sunday. I'll try to snap some shots before I put it together and post later.

[kerowako]

I changed the pawl spring on an '03 Le Mans last month, using the same "improved" aftermarket spring. Identical symptoms: less force on the upshift than the downshift; wouldn't quite return to catch the next gear up. I was puzzled as well, until I examined the geometry of the Guzzi shift change design.

 

It is inherent in the basic design that the up shift will require less force than the downshift. Just wiggle the gear lever from neutral on any V11- there is a measurable difference. The reason is the bias of the pawl spring force relative to the heavier centering spring. The moment arm that the pawl spring has adds to the otherwise neutral centering spring force in the down direction, and subtracts from it in the up direction.

 

The Guzzi engineers accounted for this when determining the force (coil angle) of the pawl spring. Unfortunately, the "engineers" for the aftermarket spring did not, and made the spring too heavy. Compare the angle of the stock spring to the aftermarket item. The aftermarket spring has just slightly too much force to allow clean return of the shift lever to center.

 

I ended up putting a new Guzzi spring in. The original spring (with roughly 5K miles on it) show NO signs of impending failure, but since the customer was concerned with probably failure, I changed it anyway. He now carries THAT as the spare.....

[bigbikerrick]

I changed the pawl spring on an '03 Le Mans last month, using the same "improved" aftermarket spring.  Identical symptoms: less force on the upshift than the downshift; wouldn't quite return to catch the next gear up.  I was puzzled as well, until I examined the geometry of the Guzzi shift change design.

 

It is inherent in the basic design that  the up shift will require less force than the downshift. Just wiggle the gear lever from neutral on any V11- there is a measurable difference.  The reason is the bias of the pawl spring force relative to the heavier centering spring. The moment arm that the pawl spring has adds to the otherwise neutral centering spring force in the down direction, and subtracts from it in the up direction.

 

The Guzzi engineers accounted for this when determining the force (coil angle) of the pawl spring. Unfortunately, the "engineers" for the aftermarket spring did not, and made the spring too heavy. Compare the angle of the stock spring to the aftermarket item.  The aftermarket spring has just slightly too much force to allow clean return of the shift lever to center.

 

I ended up putting a new Guzzi spring in. The original spring (with roughly 5K miles on it) show NO signs of impending failure, but since the customer was concerned with probably failure, I changed it anyway. He now carries THAT as the spare.....

80539[/snapback]

I assume you tried the racecrafter spring from oklahoma, correct? I have one I was going to install before the original failed, but am hesitant now... maybe we should bring this issue to the attention of "Bonnie in OK." sometimes stronger is not necessarily better!

[Dan M]

I assume you tried the racecrafter spring from oklahoma, correct? I have one I was going to install before the original failed, but am hesitant now... maybe we should bring this issue to the attention of "Bonnie in OK." sometimes stronger is not necessarily better!

80558[/snapback]

 

Yes, that is where I bought my spring. It is not any stronger than the orignial but the bend was different causing it to be wound tighter when in use. Also, I measured the inside diameter and it was not any bigger than the stock one so I don't think it will solve the short life problem by simply replacing one. I did file down the boss that it rides on to about 15.4mm and reshaped the spring for a more "relaxed fit". (kind of like the jeans I need to buy at my current age & girth) I don't feel any binding (unlike my waistline) at the end of it's travel so I believe the problem is solved.

 

I took some photos before I reassembled to help explain and I'll post them soon.