Re: [RBW] Near-Catastrophic Rim Failure
I've blown front tires on steep descents, due to over-heated rims (scary crashes). But never a rim itself. I agree with Grant, it's most likely your rim was compromised by a stress riser in the form of some grit on your brake pad. That, or the seam on the rim was defective in the first place. - Andrew, Berkeley On Dec 4, 2011, at 6:35 PM, Ray wrote: > 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 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.
Re: [RBW] Near-Catastrophic Rim Failure
On 12/4/11, Tim McNamara wrote: > > I've seen this before. Usually it is from braking wear thinning the > sidewall over time, more prevalent for people who ride in hilly or > mountainous terrain and/or in rainy weather a lot. The road grit and slurry > that gets on the rims forms a nice grinding pace. I've *had* this, as per Tim's description, happen before (Ritchey Girder rim)... fortunately however, while on the stand! Was inflating a Pasela x35 to a higher pressure than I now prefer, when kaboom! 50% of the sidewall sheared/collapsed away... The rims were *nowhere* as near pristine-appearing as Ray's though- instead, exactly fit the above description on my Boston and Pittsburgh winter commuter. Inspection afterward taught me concave rim wear is A Very Bad Sign. =- Joe Bunik Walnut Creek, CA -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
On Sun, 2011-12-04 at 17:05 -0800, Ray Shine wrote: > 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. So you've eliminated installation issues and it sounds like you've eliminated overheating as well. Rim wear is the prime suspect, in my estimation. -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
Sheesh, this is incredibly bad karma. Me, I'd stay off of that road. -JimD On Dec 4, 2011, at 4:35 PM, 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? > > Here are the pix: > > http://www.flickr.com/photos/8581354@N03/sets/72157628281638979/with/6455986331/ > > > > -- > 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.
Re: [RBW] Near-Catastrophic Rim Failure
On Sun, Dec 4, 2011 at 16:35, Ray wrote: > Could this failure resulted from the long braking over-heating the rim > and the pressure blowing it out? Seems strange, but, can that happen? I'm wondering if the heat caused the tire to blow out, and it was the force of the tire blowout that then destroyed the rim? James Black Los Angeles, CA -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
On Dec 4, 2011, at 6:35 PM, Ray wrote: > Could this failure resulted from the long braking over-heating the rim > and the pressure blowing it out? Seems strange, but, can that happen? I've seen this before. Usually it is from braking wear thinning the sidewall over time, more prevalent for people who ride in hilly or mountainous terrain and/or in rainy weather a lot. The road grit and slurry that gets on the rims forms a nice grinding pace. Sometimes the sidewall is scored by a small pebble or bit of metal that gets caught in the brake pad. And once in great a while the cause of the failure is an extrusion flaw. Glad you weren't hurt! It might be that your long braking heated the rim and caused the blowout, which took the weakened rim with it. When the rim gets really hot, the rubber of the sidewall along the bead gets hot and slippery and can lift over the rim. -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
No. I used to run these same wheels on my Canti-rom with 28s, but I've been using 32s on them for several years. Yes, and thanks to all for the best wishes. I'm fine, but can't help thinking that mountain does not want be on it for some reason… From: cyclotourist To: rbw-owners-bunch@googlegroups.com Sent: Sun, December 4, 2011 5:29:51 PM Subject: Re: [RBW] Near-Catastrophic Rim Failure Were the rims particularly narrow? 32mm isn't all that wide, but "fat" tires on narrow rims can lead to catastrophic failure. I wouldn't think this is the situation, but maybe one more variable that lined up against you today. Glad you could walk away from it and hope you're not too shaken. On Sun, Dec 4, 2011 at 5:05 PM, Ray Shine wrote: 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 >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. > -- Cheers, David Redlands, CA -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
Were the rims particularly narrow? 32mm isn't all that wide, but "fat" tires on narrow rims can lead to catastrophic failure. I wouldn't think this is the situation, but maybe one more variable that lined up against you today. Glad you could walk away from it and hope you're not too shaken. On Sun, Dec 4, 2011 at 5:05 PM, Ray Shine wrote: > 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 > *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. > -- Cheers, David Redlands, CA ** -- 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.
Re: [RBW] Near-Catastrophic Rim Failure
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 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.
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.
