Series "B" RFM

[mr.hutch]

Hi Albervin,
I have fitted iwis chains on the last three occasions and have never had any problems. They all got a regular dose of spray grease and lasted very well.
The last set of bearings I replaced came from a local bearing outlet, I don't think they were NTN, but they had the same numbers stamped on them as the originals and were, yes, about a third the price of Timken. Again, no problems, they have been installed for many thousand of miles, sorry I can't remember the name though. ( might have been SKF) I suppose if I was feeling really kind I'd go out in the freezing cold and do a bit of dismantling, but it's dark now, please forgive.

go carefully, mr hutch

David, thank you for both your input and humour. Yes, I have a 19" rear wheel. I would have thought the change in RFM was more about tyre width than diameter but I admit I know little about the reality of engineering. Surely no-one fitted a 21" rear wheel!!? There was a change of nomenclature when wheels were referred to by overall diameter (wheel + tyre) then wheel only which reduced sizes from 26" to 21" or 20"....
Anyway I reckon I should get by with a 4.10 even if I have to "push it out". Now does anyone have any experience with iwis chains? While we are at it, has anyone used NTN bearings that cost 1/3rd the price of Timken?