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#11
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Phils with threaded flange?
Jay Beattie wrote:
On Apr 5, 8:03 am, Tim McNamara wrote: In article , Chalo wrote: One of my friends has an anecdote about a triplet racing team doing a hillclimb event with high-spoke-count Phil hubs of such construction, and quickly collapsing their rear wheel when the drive flange screwed further up the shell. I wondered about that possibility looking at the photos, but can it actually happen? The trailing spokes would have to stretch lots and lots to allow the flange to rotate on the hub shell, like centimeters. That was the lore in the '70s -- although it never happened to me or anyone else I knew. It always seemed to me back then that there was a need to tell tales about equipment. Everyone rode the same Campy NR/ SR. Nothing worked that well or broke that much, so we had to invent big differences and lore -- like people who could feel the difference between 3 and 4 cross.-- Jay Beattie. "It" happened to me twice (tandem, circa 1982). But let me explain - the flange the freewheel rests against didn't turn, it was simply forced inward over its threads (ripping out the aluminum threads in the process. The spokes would /not/ allow the flange to turn, no. These were both even earlier Phil hubs, where the flange had a ?chamfer? on the inner face. Hmmm... how to describe it? The flange-shell interface was narrower than later models when measured along the axle direction because the flange inner diameter was cut away for, oh, say 3-6mm on the inner face. Crude ASCII art below ____ | | | | | | -crude aluminum flange cross-section | \__ (NOT! to scale!) ___\_______|_____ | | - stainless hub shell | We sent the first one [1] back to Phil and were told they'd seen the problem before, and were working on a new design. Of course they replaced our hub with the new kind. To my eyes at least, the only change was that the inner face of the flange went straight down to the shell, increasing the number of acting threads. We killed a second original-design hub in the next year or so, and that one was replaced by Phil as well (we had both a 48-spoke set of touring wheels and a pair of 36-spoke fast/light wheels.) [1] Killed the first one on our tandem at the Fargo Street Hill climb in LA with a one-to-one gear and youthful enthusiasm. It died with just one pedal stoke that was way too hard. Second one died on a steep bit on a century ride. In both cases, suddenly the bike slowed and the pedaling "went soft" - it was clear that if we torqued on the cranks, the freewheel was turning faster than the wheel was. In the first case we probably only went about one turn of the cranks (hence one of the freewheel), it was a sickening feeling. In the second case somehow we limped back to the start of the ride (by a severe shortcut), so apparently we didn't toast the threads so badly. I'm not sure how that makes sense, perhaps we bottomed the freewheel on the hub shell. In neither case did the wheel collapse, but both were strong and treated very gingerly after the "smoosh". No problems at all with the two replacements, and we've since put over ten thousand miles, some very steep, on them. I have absolutely no idea how the Ebay/OP hub broke, but it doesn't look like it was in use, the failure mode that we experienced was radically different. Mark J. |
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#12
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Phils with threaded flange?
Mark wrote:
Jay Beattie wrote: Tim McNamara wrote: Chalo wrote: One of my friends has an anecdote about a triplet racing team doing a hillclimb event with high-spoke-count Phil hubs of such construction, and quickly collapsing their rear wheel when the drive flange screwed further up the shell. I wondered about that possibility looking at the photos, but can it actually happen? The trailing spokes would have to stretch lots and lots to allow the flange to rotate on the hub shell, like centimeters. That was the lore in the '70s -- although it never happened to me or anyone else I knew. It always seemed to me back then that there was a need to tell tales about equipment. Everyone rode the same Campy NR/ SR. Nothing worked that well or broke that much, so we had to invent big differences and lore -- like people who could feel the difference between 3 and 4 cross.-- Jay Beattie. "It" happened to me twice (tandem, circa 1982). But let me explain - the flange the freewheel rests against didn't turn, it was simply forced inward over its threads (ripping out the aluminum threads in the process. The spokes would /not/ allow the flange to turn, no. That explains the failure in my friend's tale much better. And it makes sense, really-- the freewheel's steel threads should be strong enough to shear an equal number of aluminum threads when they tighten against each other hard enough. Chalo |
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