Gearbox play? Knock?

[jaleem]

Today 04:44 PMjaleem
Hi, need help, I have a 99 Blackbird with 56 k miles, I changed the chain and sprockets for the mot last month, now I heard a loud knock, I noticed that when in any gear there is about 1 1/2 to 2 inch play from the crankshaft until the wheel starts turning causing the knock, I removed the chain and can't find any play in the crankshaft until I put it in any gear then I get the play again. Anyone have any ideas? Could it be the clutch or gearbox? Thanks

 

[Howard]

Cush rubbers? :dunno:

 

[jaleem]

Hi thanks I will order them,

 

[Howard]

Hi thanks I will order them,

It's only a guess, best bet is to take the rear wheel off and check them first before ordering.
Others will be along shortly with other ideas...............................

 

[jaleem]

Hi I checked the Bike I have the chain and rear wheel off and the play is at the crankshaft I can feel it when in gear and turning the small sprocket by hand,
:bang:

 

[jaleem]

Excessive play

Hi I checked the Bike I have the chain and rear wheel off and the play is at the crankshaft I can feel it when in gear and turning the small sprocket by hand,
:bang:

 

[Howard]

I have no idea, apart from you will get a certain amount of play anyway.

Anyone else like to put forward any help? :dunno:

PS. Maybe the clue is that it started after you changed chain & sprockets?

 

[jaleem]

Hi I when moving off I can hear a loud knock A's it takes up the slack.when on the center stand and I turn the rear wheel by hand it turns almost 2 inches before the small cog turns. The noise is definitely from the small sprocket, can anyone put their blackbird on the center stand and turn the rear wheel and let me know if there is any play ? Thanks:bang:

 

[carler]

On center stand, in gear, wheel turns 1.5 inches +. Small sprocket moves all this time so the play is inside the gearbox.

 

[Centaur]

Have you checked the rear wheel alignment and more importantly the slack in the chain. The slack should be checked by having the bike off the stand and having someone of the normal riding weight sitting on the bike while you check the slack. I have the feeling your chain is too tight. IMHO Better too slack than too tight unlike some other thing that comes to mind. lol

 

[slim63]

have you checked for side to side movement on the front sprocket and or output shaft splines (rather than round & round)

 

[andyBeaker]

Have you checked the rear wheel alignment and more importantly the slack in the chain. The slack should be checked by having the bike off the stand and having someone of the normal riding weight sitting on the bike while you check the slack. I have the feeling your chain is too tight. IMHO Better too slack than too tight unlike some other thing that comes to mind. lol

Plus 1 on that - chain too tight

 

[andyBeaker]

Have you checked the rear wheel alignment and more importantly the slack in the chain. The slack should be checked by having the bike off the stand and having someone of the normal riding weight sitting on the bike while you check the slack. I have the feeling your chain is too tight. IMHO Better too slack than too tight unlike some other thing that comes to mind. lol

Plus 1 on that - chain too tight

 

[Howard]

Have a look here:

http://www.cbrxx.com/suspension-tires-wheels-brakes/17141-gearbox-clunk-standstill.html