David: I've seen this before on Matrix ISO rims in the 80s. They came dark anodized. Over time, the dark anodizing wore off at each spoke location. This process took years and even when worn there was only mild bumpiness when braking. If these are fairly new rims, I suspect a rim problem more than a brake problem. There may be a way to rig a dial indicator in a wheel truing stand to check the suspect surface. The wheel may be true in that it doesn't wobble, but if the braking surface is lumpy it could cause the symptoms you are experiencing.
dougP On Aug 13, 7:53 pm, "carnerda...@bellsouth.net" <carnerda...@bellsouth.net> wrote: > My 650B Sam Hillborne has Velocity Synergy rims and Shimano Deore V- > brakes with the pads that came on them. Since new the front wheel has > had a little tick with each revolution while braking. I assumed this > was a slightly raised joint line that would flatten out with normal > wear. Over the last two weeks I have had three12-15 mile rides on > gravel and chip seal roads which include some steep sections with > multiple pot holes and required heavy braking. Between these rides I > had the usual short commutes to work. I noticed that braking in the > front had become much more uneven to the point that firm application > of the front brake caused an unpleasant "thump" with each revolution. > I decided it was time to clean the braking surface. When I did I > found the front rim to be fairly deeply scored and in a pattern where > the deepest scoring corresponds to each spoke hole. This is the same > on both sides of the rim. The rear rim does not have this pattern. I > have never seen this and can't find mention of it on the internets. > The links below are to pictures I took to try to show the pattern. > Am I doing something wrong to cause this? Should I change to > different brake pads? Should I be worried about > this?http://www.flickr.com/photos/carner/4889788162/in/set-72157623654420644http://www.flickr.com/photos/carner/4889790774/in/set-72157623654420644/http://www.flickr.com/photos/carner/4889196607/in/set-72157623654420644 > David -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
