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Cantilever rear hub offset from centerline |
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Balor 
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 Posted: 23 November 2021 at 7:52pm |
Prepreg? Over 3d printed mandrel? Printing PEEK is way above my pay grade :) Wet lay up and compression of course.
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Balor
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Posted: 05 December 2021 at 2:47pm |
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Parental advisory: explicit content:
Ok, it would likely be already ok for someone of less, ahem, bulky stature, but definitely an other wrap of the lower half needed!
No creaks and pops detected, frame seems to be quite rigid laterally, but 2 inches of vertical deflection and about 1/2 inch of torsional deflection do seem excessive... I think I want about half that. Anyone who rode ratracers, how much torsional deflection was considered 'ok'?
Edited by Balor - 05 December 2021 at 2:49pm |
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Balor
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Posted: 06 December 2021 at 7:17pm |
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Ok, after adding some wraps to keep flex in the tail under control I did test assembly, seems fine, and I think I can even fit a 24" with a narrow tire in there.
  Now I need to think about seat mountings. |
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Balor
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Posted: 20 December 2021 at 6:22pm |
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https://youtu.be/sVGFOTxVhlc
Well, at least I would test it this
way... It does feel 'funny', especially because it turns out my front
triangle is also a bit off (not by design but happenstance) and in the
SAME direction, make the bike even less balanced, but the feeling
quickly disappears after you simply learn to compensate for it by
leaning the bike a bit. I think going with (about half of rear)
asymmetric front as well in *different* direction should do the trick.
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XAPBob
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Joined: 15 August 2018 Location: Warks Status: Offline Points: 51 |
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Posted: 21 December 2021 at 1:44pm |
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If both wheels are off to the left, then can you mount the seat asymmetrically that way? i.e. make it so that the frame is offset, not the wheels?
Edited by XAPBob - 21 December 2021 at 1:45pm |
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Balor
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Posted: 28 December 2021 at 5:10am |
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First thing I've thought, unfortunately and funny enough the carbon seat I have ALSO have mounting holes offset a bit, and guess in what direction :)
Anyway, I did an asymmetric seat mount by 3d printing, but due to 'interference fit' with frame tube and seat reinforcements it is only about 3mm or so. I'll be creating a custom sandwich seat that should adress all those (and other) shortcomings. Anyway, I did a test ride and while the bike indeed feel very weird and pulled to the right considerably for a first two minutes, in a few minutes it felt pretty normal again! Too bad there is a lot of snow outside so nuances of high-speed stabilty will have to be tested much later...
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Balor
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Posted: 23 January 2022 at 7:34am |
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Yanto
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Posted: 23 January 2022 at 3:45pm |
Ooh, that looks cold and slippery, how does the bike ride in these conditions?
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RoyMacdonald
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Joined: 09 March 2007 Location: Rye East Sussex Status: Offline Points: 981 |
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Posted: 26 January 2022 at 1:04pm |
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For me that would be a no go except downhill. The seat is too far back from the front axel so I'd never get the loading to give the front tyre grip in the dry let alone ice and snow. I only managed on the Wasp by moving the seat forward so I was jammed up against the downtube and there was not that great gap from the downtube to the wheel. I was several kilos heavier in those days as well, but still managed to fall off due to wheelspin a couple of times.
All the best. Roy  Edited by RoyMacdonald - 26 January 2022 at 1:13pm |
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Balor
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Posted: 26 January 2022 at 8:08pm |
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Rides quite fine actually - the front tire is spiked, just not apparent because it is covered with snow, and I do get wheelspin in loose snow.
I should note that weight distribution is VERY front-biased, about 70% on the front, 30% on the back - due to long-ish wheelbase. I've used to manage to climb dirt tracks of quite significant steepness with minimal wheelspin when I've installed MTB tires (previous frame),but than I've once went down due to loss of *rear* traction in steep cornering, so this much of front weight bias is not optimal to be sure.
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russellbridge wrote: