Julian_S wrote:Sadly all Imperial bearings now cost the earth, especially the larger sizes. I rebuilt a series Landrover gearbox a bit ago and I had a long hard think and reused the ball races in the transfer casing as they were about 50 squids each. Metric would have been a tenner
Strangely enough it is metric bearing 55 mm o/d 15mm width and 32 mm i/d weird for a 1960 bike especially as none of these measurements match up to an exact imperial size. it's expensive cos it's odd I think
Paul
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
Hmmm. that's 2-5/32" 9/16 " & 1-1/4 to allow for clearance and an interference fit? Certainly odd but I'm not convinced it's metric - that makes no sense to me....
Julian_S wrote:Hmmm. that's 2-5/32" 9/16 " & 1-1/4 to allow for clearance and an interference fit? Certainly odd but I'm not convinced it's metric - that makes no sense to me....Julian
nor me either and actually I got it wrong, it's 52 mm not 55 so that makes it 2-3/64" . even the correct bearing part number 041266, which I have, measures the same??? BTW Not to take anything away form the club, they have these in stock (041266)and I have looked at the picture and it is the same as the "old bearing" picture above, still expensive at £68 though..BUT AT LEAST THEY STOCK THEM!!
Paul
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
I must say I'm never convinced about the freezer idea (although have dutifully used it). Freezer temperature is about -20C - if ambient is around 20 then you're only 40 degrees cooler. That would have the same effect as heating the alloy up to 60, ie not that much (plus of course the coefficient of expansion of the bearing will be less than the alloy).
The other problem is of course that my chips taste of gearbox oil.....
iansoady wrote:I must say I'm never convinced about the freezer idea (although have dutifully used it). Freezer temperature is about -20C - if ambient is around 20 then you're only 40 degrees cooler. That would have the same effect as heating the alloy up to 60, ie not that much (plus of course the coefficient of expansion of the bearing will be less than the alloy).The other problem is of course that my chips taste of gearbox oil.....
Well it worked, so much so that the bearing did literally drop in, when the bearing heated up and the case cooled down it is now a tight fit or are you saying that when the case heats up the bearing will become loose again?? It certainly never went in all at room temperature and would have required a bit of tapping..
Paul
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
No, I just don't think it's much of an advantage over being at room temperature. When you say "never went in all at room temperature" is that both components (which is what I would expect) or the bearing (with the case heated up)? If the latter, then I am clearly wrong in my view and am happy to accept correction.
No you are right Ian, case in the oven gas mark 6 for 20 mins and a room temperature bearing will just fall in.
don't forget to baste the case with castrol ahhh bisrto and season to taste.
iansoady wrote:No, I just don't think it's much of an advantage over being at room temperature. When you say "never went in all at room temperature" is that both components (which is what I would expect) or the bearing (with the case heated up)? If the latter, then I am clearly wrong in my view and am happy to accept correction.
Yes, both components at room temperature, I didn't try the bearing at room temp with a heated casing so I don't know.
Paul
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
