sealed bearings..!!

[J1MS]

Ive had a few conversations in the past about bearings and there suitability for use when used with rubber seals fitted... This goes back to an engine my brother built ( Small frame Vespa ) that exploded when the main bearing collapsed... So when he did the rebuild we gathered as much info as was available back then... this was before the days of the Internet.... We managed to get a little info together and a book from FAG bearings... It lists the 6305 with seals (rubber or steel) and without... If you fit this type of bearing with the two rubber seals fitted the revolution safe Maximum is only 7,100 RPM.... but without the seals fitted the same bearing has in oil, a 12,000 RPM limit... The Dynamic loading remains the same for both at 3,800 Lbs... and the static load is 2500Lbs again for both.... For the same bearing running on steel seals the revolutions safe limit is 10,000 RPM... But this bearing (steel sealed) wouldnt normally be used as a drive bearing....

So if anyone decides to use a 6305 2RS type bearing as a drive bearing in a Lambretta... keep in mind the rev limit may be lower by a considerable amount...
If you do run one make sure you remove the bearings rubber seal on the side that faces the drive sprocket ( This will allow it to run in oil), this will raise the rev limit to near the 12000 RPM maximum of the standard bearing... which is what a few scooter shops reccommend... and not to use both seals.... The technical Info is from an old FAG bearing book that I obtained some 25 years ago... but as I had been asked a few times.. "should I keep both seals on"... I thought there must be others as well thinking of doing this.... and I wouldnt reccomend it... owing to FAG's technical info....

[cryogenic]

Nice one bud see ya thursday morning

[Mel K]

Were are you going thursday morning?

[davidblythe]

thanks for the post,

always run with one seal removed but it did answer the thought why dont i just rely on the grease within the sealed bearing, max revs being the answer

again ta, would appreciate more posts like this

[goldeneye]

removeing the inner seal makes the grease in the bearing redundant, it"s just trying to give some "belt n braces" to the driveside oil seal. P200 (late) run double oil seals with captured grease , with no problems. but are not subjected to the RPM of a D/S oil seal due to the gearing etc. , as these are rear hub bearings. been using Viton seals for years.... bearing services , thornaby, u.k. . just shop around .