[singleminded]

No It's not needed for normal road use. I have a '32 Model 9A. That's a 600cc overhead valve bike, looks like yours but different engine and i don't have the bearing or any way of fitting it..The M90 engine I have does have the fitting but i wouldn't be bothered myself..John

[Angus]

yes it is as you described, the question is now do i need it on a s.v. Lion or do i make a  copy without the bearing, if so the next thing i would need is pictures or drawings, Sorry to be a pain but down here in Cornwall Sunbeams are a bit thin on the ground so i am unable have a look at someones machine close by

[singleminded]

Is the flat around the opening where the mag shaft goes in and is there a bolt sticking out the back of the case near the mag hole?.
If there is a bolt then it is for securing an out rigger bearing to support a machined mag drive pinion, these are usually only found on the model 90's as far as I know..John

[phutton]

I can't quite visualise what you mean. Any chance of a photo?

P.

[Angus]

Hello beamers
  On my lion mag drive chaincase at the back is a machined flat surface i do not have anything that fits here can  someone help me with pictures, drawings,measurements or sell me the missing part .
    Thanks
          angus