So, has anyone ever seen the rear disc/rotor crack between the cooling holes? My 78 R100RS has cracks between almost every set of holes going center outwards. I had a rear bearing fail on my way home from the Stanley Stomp. The bearing failure seems to have been caused by a failed seal that let water into the wheel when I had to ride through a creek to get to the camp. I had no indication that I had a problem until I was slowing down to pull into a roadside attraction and heard a sound like I was dragging something. Of course the trip ended at that point. Fast forward, got the wheel into the shop for new bearings and seals and the mechanic pointed out the cracks. Freaked me out. What could cause the cracks? That's my question. Of course I checked my front discs very carefully and thankfully no issues. Any thoughts? 125000 miles by the way. Same with the bearings. Just lubed every tire change.
I'm in the market for a new/gently used brake rotor. (Same part # as the front disc by the way).