calling all flat-tire forensic detectives ... - The Chainlink2024-03-28T09:07:17Zhttps://thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?id=2211490%3ATopic%3A701560&feed=yes&xn_auth=noYou have a cut tube and a cut…tag:thechainlink.org,2013-06-10:2211490:Comment:7047052013-06-10T13:53:43.170ZChristopher Wallacehttps://thechainlink.org/profile/ChristopherWallace
<p>You have a cut tube and a cut tire just above the bead. Normally cut tire carcass at the bead is caused by tire removal using a tool scraping along the tire bead cutting the cords of the carcass. A new tire should not have be removed yet. A tire with nylon cording can be cured to over 200 degrees Fahrenheit melting the fibers. Once in a while the rubber will not fill the tire mold fully and cause thin bead on edges of a tire making it very hard to seat correctly, this will not normally cut…</p>
<p>You have a cut tube and a cut tire just above the bead. Normally cut tire carcass at the bead is caused by tire removal using a tool scraping along the tire bead cutting the cords of the carcass. A new tire should not have be removed yet. A tire with nylon cording can be cured to over 200 degrees Fahrenheit melting the fibers. Once in a while the rubber will not fill the tire mold fully and cause thin bead on edges of a tire making it very hard to seat correctly, this will not normally cut the tire at the bead. </p>
<p>If I were you mechanic I would inspect the tire to see if the carcass was cut or if it tore. If it was cut by a scraping motion the rubber over the nylon cord would be removed, if it tore the rubber would be split but not scraped off. A tear is a manufactures issue, a cut would be either a mechanics installation or a consumer removal/ tool usage issue. </p>
<p></p> One other note about brake pa…tag:thechainlink.org,2013-06-09:2211490:Comment:7041412013-06-09T04:22:27.342ZGreen Machine Cycleshttps://thechainlink.org/profile/EzraHozinsky
One other note about brake pad adjustment as it relates to tire sidewall preservation and damage: if your brake calipers are flexible, as is often the case with sidepull brakes on road bikes from 30 or more years ago, and with department store bikes of any era, the attitude of the pad to the rim will change upon hard braking. As the pad grabs the rim from the friction created on contact, the caliper will flex in the direction of wheel rotation, lifting the leading edge of the pad toward the…
One other note about brake pad adjustment as it relates to tire sidewall preservation and damage: if your brake calipers are flexible, as is often the case with sidepull brakes on road bikes from 30 or more years ago, and with department store bikes of any era, the attitude of the pad to the rim will change upon hard braking. As the pad grabs the rim from the friction created on contact, the caliper will flex in the direction of wheel rotation, lifting the leading edge of the pad toward the tire. If the pad was already set close to the tire, hard braking could cause the pad to cut a groove into the sidewall. Similarly, if the pivot(s) of your brakes are too loose and have play, the pad could behave the same way as above. This issue won't be noticeable if you simply squeeze the brake while the bike is stationary, as it requires the friction of braking action to manifest. Unlikely situation, but theoretically possible in your case.<br />
<br />
I think it's more likely the tube was pinched under the bead, given how new the tire was. Straight side rims are still…tag:thechainlink.org,2013-06-08:2211490:Comment:7037902013-06-08T15:11:39.262ZJohn C. Wilsonhttps://thechainlink.org/profile/JohnCWilson
<p>Straight side rims are still useful and can be used safely with modern tires. The first well-distributed approximately modern tire was the Schwinn LeTour, introduced in 1973 and labelled for 85psi. There were darn few hook-edge rims around to mount it on and the Schwinn engineers were extremely conservative.</p>
<p></p>
<p>Bike shops are super cautious about this one because they know the customers do crazy shite to bikes and the shops can become liable. Here are some cautions-- We are…</p>
<p>Straight side rims are still useful and can be used safely with modern tires. The first well-distributed approximately modern tire was the Schwinn LeTour, introduced in 1973 and labelled for 85psi. There were darn few hook-edge rims around to mount it on and the Schwinn engineers were extremely conservative.</p>
<p></p>
<p>Bike shops are super cautious about this one because they know the customers do crazy shite to bikes and the shops can become liable. Here are some cautions-- We are talking old bike parts. Inspect thoroughly before use. Use a wide tire. Wide tires need less pressure. Old tires were all wide by current standards. The rims are wide too. Big heavy people or riders who always carry expedition loads are better off with new parts. Above 200# rider weight the old rims won't last long. Above 220# forget it.<br/> <br/> <cite>Allen Wrench said:</cite></p>
<blockquote cite="http://www.thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?id=2211490%3ATopic%3A701560&page=2#2211490Comment703465"><div><div class="xg_user_generated"><p>older (up to 1970s?) rims didn't have the hook edge that modern ones do. Even most racing bikes could manage only about 65 lbs pressure. If you have say an old Schwinn and put a new tire on it that says 90 lbs, if you fill it up higher than 65 the edge slips off, the ride gets wobbly, and it goes bang with a big long gash in the tube. Could that be it? Probably not with the tire injured too, but hmm.</p>
<p></p>
</div>
</div>
</blockquote> older (up to 1970s?) rims did…tag:thechainlink.org,2013-06-08:2211490:Comment:7034652013-06-08T03:57:59.268ZAllen Wrenchhttps://thechainlink.org/profile/AWrench
<p>older (up to 1970s?) rims didn't have the hook edge that modern ones do. Even most racing bikes could manage only about 65 lbs pressure. If you have say an old Schwinn and put a new tire on it that says 90 lbs, if you fill it up higher than 65 the edge slips off, the ride gets wobbly, and it goes bang with a big long gash in the tube. Could that be it? Probably not with the tire injured too, but hmm.</p>
<p></p>
<p>older (up to 1970s?) rims didn't have the hook edge that modern ones do. Even most racing bikes could manage only about 65 lbs pressure. If you have say an old Schwinn and put a new tire on it that says 90 lbs, if you fill it up higher than 65 the edge slips off, the ride gets wobbly, and it goes bang with a big long gash in the tube. Could that be it? Probably not with the tire injured too, but hmm.</p>
<p></p> Some months ago I read that i…tag:thechainlink.org,2013-06-08:2211490:Comment:7033592013-06-08T01:21:14.465ZSlowCoachOnTheRoadhttps://thechainlink.org/profile/SlowCoachOnTheRoad
<p>Some months ago I read that it would be better for my chronic low back pain (no spasms in a year now) to keep the tires slightly less than fully inflated, so that they have a bounce and they minimize the impact of each bump in the road. I was getting lots of flats. In the end, inflating the tire fully put an end to that. It was that simple. I too was looking over the rims carefully for something sharp, but no, it was just me bouncing over a less than optimally inflated tire.</p>
<p>Some months ago I read that it would be better for my chronic low back pain (no spasms in a year now) to keep the tires slightly less than fully inflated, so that they have a bounce and they minimize the impact of each bump in the road. I was getting lots of flats. In the end, inflating the tire fully put an end to that. It was that simple. I too was looking over the rims carefully for something sharp, but no, it was just me bouncing over a less than optimally inflated tire.</p> Got enemies with knives?tag:thechainlink.org,2013-06-08:2211490:Comment:7033562013-06-08T00:58:14.574ZGene Tennerhttps://thechainlink.org/profile/GeneTenner
<p>Got enemies with knives?</p>
<p>Got enemies with knives?</p> Simple way to tell if it was…tag:thechainlink.org,2013-06-08:2211490:Comment:7034412013-06-08T00:19:50.633ZJohn C. Wilsonhttps://thechainlink.org/profile/JohnCWilson
<p>Simple way to tell if it was a brake pad: Where is the pad rubbing now? I assume you've got a tire on the rim at the moment. Are you still braking on a tire? Squeeze hard. This is also a good time to check and see if maybe the brake pads are flopping around, changing position just from taking wheels in and out. If all answers are negative, it wasn't the pads. If any answer is positive, move those pads before you destroy the next tire.</p>
<p></p>
<p>Yes, it could be a manufacurer's defect…</p>
<p>Simple way to tell if it was a brake pad: Where is the pad rubbing now? I assume you've got a tire on the rim at the moment. Are you still braking on a tire? Squeeze hard. This is also a good time to check and see if maybe the brake pads are flopping around, changing position just from taking wheels in and out. If all answers are negative, it wasn't the pads. If any answer is positive, move those pads before you destroy the next tire.</p>
<p></p>
<p>Yes, it could be a manufacurer's defect and covered under warranty. That is a one in a thousand shot. Even if you can get it replaced that way. Better to search for the cause before you go there.</p> Forensic work without directl…tag:thechainlink.org,2013-06-07:2211490:Comment:7033322013-06-07T22:58:01.444Zbradford powellhttps://thechainlink.org/profile/bradfordpowell606
<p>Forensic work without directly seeing the evidence is not impossible . What would help me and anyone else following this as an exercise in forensics, is a photo. Or an explanation of what you mean't "tire was blown out"... several people who have responded took that to mean tube had been sitting under the bead of your tire and eventually lifted the bead (which has a fixed circumference) higher than the rim flange.</p>
<p></p>
<p>If that is what happened , why did it happen?</p>
<p>1.…</p>
<p>Forensic work without directly seeing the evidence is not impossible . What would help me and anyone else following this as an exercise in forensics, is a photo. Or an explanation of what you mean't "tire was blown out"... several people who have responded took that to mean tube had been sitting under the bead of your tire and eventually lifted the bead (which has a fixed circumference) higher than the rim flange.</p>
<p></p>
<p>If that is what happened , why did it happen?</p>
<p>1. Is there a "flattened" (out of round) section of your rim. That is one way, the bead can be lifted over the edge of the rim flange.</p>
<p></p>
<p>2. Did, as some suggest , the bead of the tire never get seated properly when the tire was mounted? Better than any bike repair book I've seen, go directly to Michelin tire company 's website to learn how a section of the tube under a section of the bead can lift the bead up an over the rim. The bead seat and bead seat diameter are concepts seldom discussed in bike repair books, but if one is going to be the master detective of ones own flat fixing I would recommend learning the exact minutia of this problem.</p>
<p></p>
<p>Under or over is a relative term and responders have gone in two distinct directions. Several took the phrase "just under the wire bead" to mean poorly seated bead , but Dave interpreted the casing of the tire separated "above" the bead.</p>
<p> If the <strong>tire casing</strong> in the vicinity of the "blow out" has a two inch separation from the bead of the tire my guess is that repeated abrasion with a brake pad caused the separation. </p>
<p>Is your rim "out of true" or out of "round" (does wheel spin in a <strong>true</strong> plane without wobbling, or does your wheels rim have a section of the rim that has been flattened)?</p>
<p></p> Started doing this after I ac…tag:thechainlink.org,2013-06-07:2211490:Comment:7031332013-06-07T18:21:58.479ZJulia 3.5/7.5 mihttps://thechainlink.org/profile/JuliaC
<p>Started doing this after I accidentally blew out the sidewall on an older tire by inflating to full pressure right away. Baby powder is awesome stuff.<br></br> <br></br> <cite>Bob Kastigar said:</cite></p>
<blockquote cite="http://www.thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?page=1&commentId=2211490%3AComment%3A703389&x=1#2211490Comment703389"><div class="xg_user_generated"><p>All good advise, let me add on thing: use baby power to coat the tube, it allows it…</p>
</div>
</blockquote>
<p>Started doing this after I accidentally blew out the sidewall on an older tire by inflating to full pressure right away. Baby powder is awesome stuff.<br/> <br/> <cite>Bob Kastigar said:</cite></p>
<blockquote cite="http://www.thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?page=1&commentId=2211490%3AComment%3A703389&x=1#2211490Comment703389"><div class="xg_user_generated"><p>All good advise, let me add on thing: use baby power to coat the tube, it allows it to move easily when inflating-deflating-inflating the tire/tube.<cite><br/></cite></p>
</div>
</blockquote> All good advise, let me add o…tag:thechainlink.org,2013-06-07:2211490:Comment:7033892013-06-07T18:18:32.996ZBob Kastigarhttps://thechainlink.org/profile/BobKastigar
<p>All good advise, let me add on thing: use baby power to coat the tube, it allows it to move easily when inflating-deflating-inflating the tire/tube.<br></br> <br></br> <cite>Jeff Schneider said:</cite></p>
<blockquote cite="http://www.thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?utm_source=7+June+2013&utm_campaign=7June13&utm_medium=email#2211490Comment701367"><div><div class="xg_user_generated"><p>My guess is that the tube was not seated entirely inside the tire -…</p>
</div>
</div>
</blockquote>
<p>All good advise, let me add on thing: use baby power to coat the tube, it allows it to move easily when inflating-deflating-inflating the tire/tube.<br/> <br/> <cite>Jeff Schneider said:</cite></p>
<blockquote cite="http://www.thechainlink.org/forum/topics/calling-all-flat-tire-forensic-detectives?utm_source=7+June+2013&utm_campaign=7June13&utm_medium=email#2211490Comment701367"><div><div class="xg_user_generated"><p>My guess is that the tube was not seated entirely inside the tire - i.e., that part of it was pinched under the wire bead of the tire.</p>
<p>When I mount a tire, I inflate the tube partially, then deflate it and squeeze the tire all around to make sure the bead is seated on the rim, the tube stem is straight, etc.</p>
</div>
</div>
</blockquote>