by Warkton Tornado No.1 » Wed Apr 24, 2019 5:13 pm
I must confess that if the bearings have been of good quality (basically European or Japanese) & cheap enough (or even free!) then I have gone for the standard, tighter clearance bearings.
(The designation ‘C3’ means additional internal clearance. In other words, the bearing has room for expansion if needed between the races of the bearing)
I reason that the alloy crankcase & magneto housing journals are never going to be the same fit on the outer of the bearing once the original has been replaced, that is, the fit will be a little slacker, so, as they say ‘swings & roundabouts’
As for the magneto bearing, if the crankshaft journal is wide enough for the NU2205 & the alignment is maintained, then the wider, better rated type can be used instead of the NU205.
NU2205E has a greater number of rolling elements due to the cage being moulded & therefore allows more ‘crowding’ of the rollers. They are the better type & do not cause any safety issue upon failure, unlike rear hub bearings that should never have come to market with nylon cages……