Quote:
Quote:
the "known fact" issue is exactly what started this thread. Everyone says it but no one has offered any real evidence other than saying that it is a "known fact".
All the major motorcycle manufacturers switched from using ball bearings in the steering head (the part of the the frame where the front suspension is mounted) to tapered roller bearings because the ball bearings would consistently develop a "notch" in the normal range of steering motion, typically right in the center where most loads occured.
Ball bearings are bicycle-grade technology. There's no way I'd run 'em in any axle application where they'd be expected to deal w/ significant side loads.
completely different application-- a steering head on a motorcycle only sees a range of motion of +/- 30 degrees max, and at high load, usually much less than that. it also sees a constant side load on the bearing (gravity).
yes, the tapered roller is a superior design, as it handles high thrust loads. but look at ford 9" and GM 12/14 bolt rears. they all use a flat roller bearing, IIRC, which doesn't carry thrust loads any better than a ball bearing....
I have been using green bearings in a hot street app for 9 years now, driving probably not _quite_ as extreme as scratchin's, but not far removed. my wilwood rear discs require them. my first set lasted only about 2k miles, but that was because I was told I didn't need to remove the thrust block/buttons in my diff. well, you don't if the axle is in the same position, but the way the wilwood kit was set up, it moved the axles inboard the thickness of the brake backing plate, which side loaded the bearings on the thrust block. when I replaced them, I put a spacer behind the brakes to move the axles out the 1/8" thickness of the old backing plate. almost 30k miles later, no issues.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
| 
