LH nut question

[oehlin]

Nut starter freewheel left-hand-thread from Laverda Paradise does not fit my 750SF -73
Whats wrong here ?

 

[Thomas aus LAU]

On various crankshafts, I measure 15.97 mm diameter at the thread.
You need a 24 nut for the screw nut.
It looks like the (damaged) thread on your crankshaft has been turned off and a smaller one has been cut into it.

If this is a fine thread turning counterclockwise and the disc is correspondingly stronger, it should hold up.
Don't forget the spring ring.

Thomas aus LAU

 

[oehlin]

Seems like I have to measure the thread and get a suitable nut made.

 

[Thomas aus LAU]

Sees like I have to measure the thread and get a suitable nut made.

No Problem, Check if it is left-hand-thread or right-hand-thread and if it is a fine thread.
Here you will get nearly all scres and nuts: Wegertseder
If someone used a right-hand thread, I would secure the freewheel body and the nut with e.g. Loctite 638 or a very strong screw locking agent.

Thomas aus LAU

 

[oehlin]

The thread i left hand and I will check the pitch

 

[oehlin]

M14*2,0 LH might work. Have to order and test

 

[Thomas aus LAU]

M14*2,0 LH might work. Have to order and test

The freewheel looks like a farrier worked on it .....
A 2.0 thread pitch is definitely not a (self-locking) fine thread. => Use additional security measures such as Loctite.

Thomas aus LAU