I did touch the rim, and it was hot. However, I've touched other rims on the same descent and they seemed hotter. I never rolled faster than 10 mph when I started the descent. I scared. So, I was on the brakes for about 3/4 mile on an 18% descent. The tires, tubes and wheels have been mated for several months, and I have ridden the bike a lot, maybe 3 or 4 hundred miles. This was the second trip down this grade on this bike this week. I normally do inflate to about 80, but thought they seemed "squishy", so I added 5. The sidewall says 95.
I checked the brake pads and the sidewalls of both wheels like Eric suggested, and see nothing out of the ordinary. ________________________________ From: Steve Palincsar <palin...@his.com> To: rbw-owners-bunch@googlegroups.com Sent: Sun, December 4, 2011 4:43:48 PM Subject: Re: [RBW] Near-Catastrophic Rim Failure On Sun, 2011-12-04 at 16:35 -0800, Ray wrote: > Took a nice ride across the bridge and up to Hawk Hill, planning to > get home in time to catch the 49er game at the end of 1st quarter. I > didn't make it. My rear rim blew out as I took a slow (translated: > continuous braking down 18% descent to hold speed at 10(-)mph.) > descent down back side of Conzumel Road toward the lighthouse. > > Because I crashed on the same section of this road in January and > broke my collarbone, I have been taking this descent extra carefully > and slowly now that I am back on the bike. Just as I was in the last > tight turn before the road levels out to a reasonable grade, my rear > tire popped and blew out. > > I managed to stay upright and bring it to a stop against a bank. > There, I discovered that my rear rim blew out and a 18" section of the > sidewall bead just blew out and tangled up in the spokes and > chainstay. The wheel rims are Araya. Just prior to leaving home, I > pumped up the rear Pasella x32 to 85 pounds. The wheels are about > three years old. No prior wheel trauma. > > Could this failure resulted from the long braking over-heating the rim > and the pressure blowing it out? Seems strange, but, can that happen? You didn't happen to touch the rim to see if it was actually hot, did you? Just to cast a glance over the usual suspects -- is this by any chance a non-hook bead rim? Is 85 psi a usual pressure for you, that you've used successfully with this particular tire/tube/rim combination before? Was the tire recently installed, or has it been in service in this configuration for some time? And by the way, I'm very glad you are unhurt. -- 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-bunch@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. -- 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-bunch@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.
