@Mark, the symmetry of the bulge was diagnosed in a truing stand. Everything looked great about the rim except for a <2mm bulge on each side. There wasn't excessive wear observed by eye or finger. I did not measure the thickness of the wall to confirm wear, though. And admittedly there was not a flat spot to indicate impact damage to the top of the walls. The reason I'm convinced it is impact related is that a buddy and I were bombing down a rutted gravel road at about 30mph and I hit a rock and bottomed out badly. We stopped to see if I pinch-flatted, but I had not. The bulging did not happen that day or even that week, but it was soon thereafter that a slight rub started and I put the wheel in a truing stand. It is entirely possible (maybe probable) that brake wear contributed to the weakness of the rim. I chose to ride the rim another 1000 miles because the rim seemed fine otherwise. I'm not sure that was advisable.
-Patrick On Wednesday, February 28, 2018 at 3:12:11 PM UTC-5, Mark Anderson wrote: > > On Wednesday, February 28, 2018 at 9:06:40 AM UTC-6, Patrick Cronin wrote: >> >> >> I'm pretty sure an impact caused the bulging as both sides were equally >> protruding when the rubbing first happened. >> > > Is your evidence that both sides were bulging equally the observation that > the rim would strike both brake pads at the bulge? > > Striking both pads does not imply a symmetric bulge. A one-sided bulge > will rub both brake pads as long as the bulge is big enough to take up the > total pad clearance on both sides of the rim. The bulge pushing on the > proximate brake pad will cause the opposite brake pad to be pulled against > the other, non-bulging, side of the rim. > > I have a similarly worn-out and cracked rim that I should get around to > fixing someday. It binds both brake pads, but only one side bulges, as > measured on a truing stand. BTW, the bulge can only be measured with an > inflated tire. Take off the tire, the bulge relaxes and the rim seems > perfectly true. > > -- > Mark > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
