Locked Up

[DaveinCanada]

Hi All,

I've installed a new chain on my '73 Norton Commando 850 (yes, I counted the right links). I tried rolling the bike but it locked up 3/4 wheel turn, almost as if the brakes kicked in. I'm assuming because a new chain is on, the gears are engaged because now my kickstart lever is stuck and my transmission arm won't change gears (stuck in 2nd). Any advice what this could be or what I can do to unlock it all?

Dave

 

[htown16]

You need to get it into neutral. Try to turn the wheel forward as you lift up on the gear lever.

 

[TBW]

Dave,
Yep sounds like it’s jumped into gear. basic suggestion till the brains of the group chime in:
Get the bike on the centre stand - on a plank of wood -so rear wheel clear of the ground.
Plugs out, hand rotate the rear wheel and try changing gear into neutral…

 

[DaveinCanada]

Gave it a try but not working. The back wheel is fully locked with no movement. No chance to hand rotate it. Tried shaking it and playing with the trans lever but no luck.

 

[L.A.B.]

I've installed a new chain on my '73 Norton Commando 850 (yes, I counted the right links).

How many links? How many teeth on the front sprocket?

 

[DaveinCanada]

How many links? How many teeth on the front sprocket?

Counted 99 links (pitches) per the manual

 

[DaveinCanada]

Counted 99 links (pitches) per the manual

According to the manual the sprocket should be 26 teeth, but i didn't count

 

[L.A.B.]

According to the manual the sprocket should be 26 teeth

21 not 26. Crank sprocket is 26.

 

[DaveinCanada]

21 not 26.

Odd because in my Technical Data section it says 26. Maybe because it's a Canadian bike? Do I have the right amount of chain links?

 

[DaveinCanada]

Should I take the change off to try an free up things? Should I open the gearbox to check the spring and gear? I'm stuck like my bike at this point. Nothing is moving.

 

[Fast Eddie]

What chain ?

Sounds like it’s too wide and the split link has jammed up … ie it’s wedged in between the gearbox shell and inner primary case somewhere.

 

[DaveinCanada]

What chain ?

Sounds like it’s too wide and the split link has jammed up … ie it’s wedged in between the gearbox shell and inner primary case somewhere.

The drive chain. The new chain isn't riveted, it's a slip on master link. So you think it's getting stuck? Would that prevent the transmission from shifting?

 

[L.A.B.]

Odd because in my Technical Data section it says 26.

"Engine 26T" not gearbox.

Andover Norton - CRANKSHAFT (ENGINE) SPROCKET - 06.0383

CRANKSHAFT (ENGINE) SPROCKET

andover-norton.co.uk

Do I have the right amount of chain links?

For a 21T sprocket yes (99 pitches so the chain should have a half link).

 

[Fast Eddie]

The drive chain. The new chain isn't riveted, it's a slip on master link. So you think it's getting stuck? Would that prevent the transmission from shifting?

I meant what kind of rear chain? Some are too wide, and the split link is obviously even wider.

If it was in gear when you wheeled it and then the whole gearbox could be jammed up.

 

[DaveinCanada]

I meant what kind of rear chain? Some are too wide, and the split link is obviously even wider.

If it was in gear when you wheeled it and then the whole gearbox could be jammed up.

I was able to change the gears. Once I started rolling it, the gears stopped in 2nd.

 

[DaveinCanada]

Ok, so I definitely know it's not the master link getting stuck. I can see the master link and would be able to remove it.

 

[DaveinCanada]

Should I start opening the gear box to have a look inside?

 

[MichaelD]

If you were rolling the bike forwards when it locked up, then I'd try rolling it backwards to unlock it

 

[ashman]

Remove the chain and see if it frees up, how tight is the chain, has it got free play movement in the chain, how tight is the primary chain or has your rear brake locked on, I be looking at these things first up, but has only happened when you installed the new chain so that be the first thing to look at, the rear wheel has to turn freely to change the gears.

 

[bmepkid]

Dave,
Take the chain off first and see if you can get the gearbox into neutral. If it was ok before you replaced the chain then it's likely that there's something going on with the chain. Take your time and look for the problem. Tearing into the gearbox right off is going to make more work. Hell, maybe you had the chain too tight.