Date: Sat, 15 Aug 1998 01:14:26 GMT
From: John Woodgate
Vernon Fueston Wrote:
>>IMHO if the retainers are bronze you have the later bearings. If
not
>>they are probably R&M and need replacing.
>
>Vernon,
>what's the problem with the R&Ms... they were the original superblends
>were they not?
As in all things English there is no CERTAIN answer, but I believe the first so called "superblends" were made by FAG. This is supported by Bacon's books which of course are not infallible.
R&M made roller bearings with straight rollers (30's technology). After the war the rest of the world went to rollers with a slight barrel shape. When Norton had the main bearing problem they went to FAG "superblend" bearings. When I called FAG they had never heard of a "superblend". According to FAG all modern bearings have the barrel shape. IMHO Norton called the replacement bearing a "superblend" to avoid admitting their stone age technology. There are a lot of bearings made the same size as the original. There are at least three different clearances as well as a plethora of retainers. The bearing people I consulted said the brand doesn't matter too much but there MUST be an E after the 306 number. This designates extended duty. All such bearings I have seen have bronze retainers. I ask for a NU306.M1 But of course you should use your own best judgement.
Vernon Fueston
"It's hard to make things fool-proof
when fools are so ingenious."