ball races headache

[berger]

I have not been to the pub, I am putting a box together and bought the two bearings for the mainshaft and the sleeve gear.the races are NKE [nike Austria quality assurance ],so as you do I got the bearings in the sandwich case and main body , when I tried to get the sleeve gear in it did not want to go any further than the end of the gearbox sprocket grooves *idea*so I got some old bearings[ plenty of them ,[ make good packers for millering etc]and tried them on 3 sleeve gears and they all gently tapped on and came off without *conf2*now drastic action was required so sleeevy gear went in lathe and after much emerying and trial fitting eventually sleevy gear slotted home with gentle tapping this was a long job to do. now it was time to put the sandwich plate on, NO WAY so I got mainshaft out and tried some old bearings which of corse slotted home as they should so mainshaft in lathe and much emerying again and eventually I was happy with the fit .SO all the old bearings have got the stamping numbers 6207 [ the big ones] and LS8 the small races] all made in England,The new races are stamped 6207 the biggy and LJ3/4 the small one which I understand is the equivilant to the LS8 so why is there a marked difference in these races that would never have fitted even if hit with a 7Lb hammer   ps I am going to the pub tmow to celebrate because if I hadn't got a lathe etc I would be up the creek without a paddle and riding one of those other bikes . pps thanks for reading

[duTch]

 I had the same issue, not with the pub-just with the sleeve gear, was only at a couple of spots so out came the Dremel with a stone tip, didn't take so long 

[berger]

well I had the mic on the sleeve gear and mainshaft where the smaller race fits and got a good thou  off  the buggers before I was happy with the fit because they were not going to fit in a month of sundays , and ive just remembered ive got a japenese equivelant drive side roller that doesn't want to go on a crank, whereas the others are a nice fit so there must be a thou or so difference with some makes of bearing. o well heres to tmow

[morris]

When restoring old British iron, a lathe's your mate... 

[Rex]

I may have missed the nuances in the first post, but did BSA really fit metric (6207) bearings in with Imperial LJ3/4?
Maybe something's been modified in the past to use an available bearing...probably the 6207?

[duTch]

 I think they maybe did do that but I'll let someone confirm it- I've been playing with the Gutzzi too 

[morris]

I may have missed the nuances in the first post, but did BSA really fit metric (6207) bearings in with Imperial LJ3/4?
Maybe something's been modified in the past to use an available bearing...probably the 6207?

Oh yes they did:

http://classicrider.dk/dokuments/ServiceSheets/sectionX_BSAservicesheetno703.pdf

[Rex]

That's a chart of interchangeable bearings and the relevant part numbers. For an LJ35 a 6207 would also fit, being sized at 35 X 72 X17, and an LJ25 would interchange with a 6205.

[bsa-bill]

well I'm not sure there ever was a time when it was one or the other, pistons, bores for instance, and I bet there were others