Needle bearing in scooter gearbox

[vlayco985]

Hi guys,I trying to make malossi gearcover replica.
I would like to try to insert torington needle bearings in small secondary shaft,and also on wheel shaft in transmission cover.
Neadle bearing dimensions are 12x16x10 or bk1210 closed neadle bearing.
On wheel shaft I would like to put bearing with dimension off 24x19x16,this bearing you can also find in Audi 80 gearbox shaft.
I need to grind small secondary shaft from 16mm to 12,and wheel shaft from 24mm to 19mm,after grinding shaft are going to induction heat treatment,or making it hard again.
Sorry if I have mistakes in typing,my English is not so good.😁

[gsx600racer]

Most shaft bearing surfaces are hardened. Either the whole shaft or just the surface. If you machine the surface and its surface hardened the shaft may not last long.

You mentioned induction hardening afterwards, I'm not familiar with that process, just kelm heating an oil quenching tool steels and case hardening process.

You could always test the hardness before and after with a rockwell hardness tester.

[FrankenMech]

It may be easier to bore out the housing to fit a needle bearing of the proper size to fit the shaft.

[jackrides]

Frank is right. Also, the shaft in the 6th picture is worn out.