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Tire-making: questions and answers, but mostly questions
I am still going on the tire-making thing. The last machine to convert
to digital control is nearly done. Some time ago I found a topic on the velomobile.de forum, that was about "DIY tires". I posted in it to later find out that it wasn't really about making tires; it was about making home-made wooden 20" tubular rims, on which to mount cut-down tubular tires. People talked anyway tho and at one point someone asked how I was folding the casings I was making: was I folding both edges over to the same side, or in a Z-arrangement (which he said was described as the "Italian method"). From that time I would occasionally search online for any information about this term, or of bicycle casing methods in general, and I've never found anything. I've even tried searching for pertinent German and Italian terms, and got nothing.... Is there any info online that any of you have come across? Or even any books (printed) that delved into the matter? There's more info about making tubulars, but then,,, it seems that most tubulars are made about 98% the same. ------ Once in a while I turn up a bit more info, but it takes a lot of looking to find even a little something new. On this page- http://www.cyclingweekly.co.uk/news/...factory-176590 tiny--------- http://tinyurl.com/ppgp5dc {points are numbered to make arguing easier} [Item #1] First is this bit: "... The first test sees the tyre run against a drum at 50kph continuously for an entire week — the equivalent of 7,000km — also receiving three shocks from various angles with every rotation, the perfect simulation for your average British road surface. ..." You see one of these machines in the "How It's Made" video for bicycle tires (that was also made at a Continental factory, IIRC) but they don't say how fast or how far a tire gets test-run. (~4349 miles @ 31mph, for the non-conformant among us) [Item #2] The next interesting part is this bit: "... Second, Continental tests how the tyre interacts with the rim. The rim is lubricated with silicone and the tyre pumped up to twice its maximum pressure (something in the region of 240psi/16.4 bar) to check that it will never pop off the rim in real-world use. ..." This would seem to cast a major question on the validity of the Brandt/Rinard cut-tire-bead tests. http://www.sheldonbrown.com/rinard/tirebead.htm Not that either test was faked--but that it represented an "ideal" circumstance, of a modern tire on a modern (dry & clean) rim, that attempted to draw conclusions about all clincher bicycle tires and rims (even those not modern, nor dry and clean). [Item #3] For a great many years, many bicycle rims did not have hooked edges and yet the tires still remained on them. If it was not due to bead strength, what other factor was there? [Item #4] Also claiming that "bead looseness plays no part" ignores the many many incidents of people experiencing broken tire beads when trying to use non-tubeless tires on Stan's NoTubes setups. Usually after a tire would break its bead cord this way, the tire was useless and would not stay mounted, even with an inner tube inside (occasionally someone would see a steel-bead break, but usually when this happened it was a kevlar-bead tire). [Item #5] If you search MTB web forums now, you may well notice that broken beads on tubeless MTB setups is not nearly as common an issue as it was 4-5 years ago. That could be for at least two different reasons: 1--tire manufacturers have adopted a more-stringent test for their products, and tire beads are made stronger now (particularly MTB tire beads...?) 2--nowadays there are more choices of tubeless rims and tires, so more people desiring tubeless setups are buying rims and tires made for that purpose. |
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