Will not downshift

[dbarb3]

Bike stranded me and would only downshift from 6th to 5th and no more.  Assumed it was spring.  Pulled selector box and springs are intact.  Since I was slammed with work I sent selector box off to have it checked and super spring installed.  Before I went any further I checked the shifting mechanism and cleaned and lubed and its working fine and hitting nothing. 

Reassembled everything today and shifts just fine 1st thru 6th but will only downshift from 6 to 5th.  Shifting forks looked fine to an untrained eye. 

Any thoughts before I set it on fire, good grief I'm really starting to hate this thing. 

 

[KINDOY2]

Too bad Phil is not around...

[Pressureangle]

Seems like somewhere I remember shaft nuts coming loose being one cause.

[stewgnu]

is the eccentric adjuster improperly set?  

[dbarb3]

I will take a look but it was shifting OK for 6,000 miles

[docc]

On 9/24/2022 at 3:21 PM, dbarb3 said:

Bike stranded me and would only downshift from 6th to 5th and no more.  Assumed it was spring.  Pulled selector box and springs are intact.  Since I was slammed with work I sent selector box off to have it checked and super spring installed.  Before I went any further I checked the shifting mechanism and cleaned and lubed and its working fine and hitting nothing. 

Reassembled everything today and shifts just fine 1st thru 6th but will only downshift from 6 to 5th.  Shifting forks looked fine to an untrained eye. 

Any thoughts before I set it on fire, good grief I'm really starting to hate this thing. 

 

Man, this is so commonly the issue on the downshift (that the shift lever strikes the Frame Side Plate). I believe the lever travel differs between various gear changes.  Worth looking at again, specifically between the gear changes that are giving you trouble.

The clutch release action feels full and complete?

 

[dbarb3]

Yes the clutch seems to be working fine, gonna take another look at shift lever   

[Scud]

Can you get the rear wheel off the ground? If so, if will be a lot easier to see what's going on with the linkage while you rock the rear wheel back and forth.

[docc]

41 minutes ago, dbarb3 said:

Yes the clutch seems to be working fine, gonna take another look at shift lever   

 

1 minute ago, Scud said:

Can you get the rear wheel off the ground? If so, if will be a lot easier to see what's going on with the linkage while you rock the rear wheel back and forth.

Maybe with the starter removed for a full view of the entire Rube Goldberg mechanism . . .

[MartyNZ]

Could the problem be related to Cash1000's experience? 

https://www.v11lemans.com/forums/index.php?/topic/21632-false-neutrals/

[pete roper]

Nut on the top shaft has wound off?

 

Thats my guess.

[dbarb3]

Beyond my limited skills it seems, any suggestions for a shop in central NC?

[mznyc]

Just for reference,I addressed notchy shifting and false neutrals,with replacing single plate clutch to twin plate,changing spring and opening pre-selector assembly numerous times (spring had already been updated with newer spring) and multitude of control adjustments ...nothing made a difference,for yucks,took a whole pre-selector assembly off a complete transmission I bought cheap,just in case,and she shifted like new.maybe reassembling old pre-selector unit and greasing and checking for anything  amiss may make it good again,but it hadn't been touched and went from proper shifting to bad shifting in a short period,may be worth keeping it as a possibility something may be slightly out of spec in there...

[footgoose]

On 9/25/2022 at 5:13 PM, docc said:

Man, this is so commonly the issue on the downshift (that the shift lever strikes the Frame Side Plate). I believe the lever travel differs between various gear changes.  Worth looking at again, specifically between the gear changes that are giving you trouble.

I'm with docc on this. Get the rear wheel up and your eyes in close. If the shift lever touches the pork chop at any point it's enough to cause the problem.

[dbarb3]

Well, I have removed starter put up rear wheel and done about everything possible and it just will not click from 6th to a lower gear, I thought it was going down to 5th but actually is between gears.   Shift lever is clear and working.

I am resigned to it being internal at this point, only shop I can find in NC is booked until December.