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#51
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On 8/29/2018 1:29 PM, jbeattie wrote:
On Monday, August 27, 2018 at 4:51:55 PM UTC-7, Frank Krygowski wrote: On Monday, August 27, 2018 at 5:52:47 PM UTC-4, jbeattie wrote: Getting into the 50/11 is no big deal in any area with hills. I could live without it, sure, but it does have a function ... I don't see the attraction or the function. At just 100 rpm, it's 36 mph. Aero drag is really high at that speed. Non-racers (and even most racers) can't put out enough power to maintain that for a more than a short while on anything near a flat road. And on a downhill you're better off tucking in and coasting. That's not true. There are a lot of grades where you can easily spin 50/11 and exceed the speed of merely coasting. OTOH, I don't push a 50/11 very often on flat land -- minus a draft or a tailwind. I can't argue with "there are a lot of grades" because, well, there are billions of grades of every steepness. But: Almost all downhill grades (percentagewise) will be either too shallow or too steep to allow any benefit from a 120 inch gear like 50-11, at least under normal circumstances. And on that tiny subset where you can reasonably get a speed benefit, the benefit will be small. It will be negligible for non-racers. ("Golly! I made it to work ten seconds quicker!") We could actually get (gasp!) technical and use Analytic Cycling or something similar to explore this. We'd have to agree on a power output, etc. In other words, on a downhill the power lost to air drag of whirling legs and cranks would be greater than the power put into the pedals. So it's far more sensible to coast. Instead of thinking about getting a high gear ratio, I'd think about improving the aero tuck while maintaining stability. And yet, I was riding a 50/11 on the way to work this morning on a mild downhill. It was a comfortable probably 80 RPM. 30-35mph. Who knows. I have no instrumentation on my bike. I was going way faster than just coasting, sitting on my son's wheel and staying ahead of traffic. He https://tinyurl.com/y8gzmbck Another motor pace to work. OK, slight downhill and drafting. I assume your son is big enough to poke a nice hole in the air. Yes, I can see it for that situation, especially because you wouldn't want to lose the draft. How does it work when he's not there? And how much speed benefit did you get following him, for how long? -- - Frank Krygowski |
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#52
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
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#53
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
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#54
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On Wednesday, August 29, 2018 at 12:48:22 PM UTC-5, wrote:
I went for a ride with a friend last Sunday and I was spun out on my 50/11 and he COASTED by me so fast I had to wonder if he had gone electric. But you said you spin out at 75 rpm. A 50x11 at 75 rpm is a whopping 26.9 mph. Frank, Jay, me, Lou, Andy and everyone else would have coasted by you sitting bolt upright with our arms in the air giving the victory salute at the finish line. I can coast up to 26.9 mph on the trails in my town, and they are converted railroad beds so they are very gradual climbs. 1%. |
#56
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
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#57
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On 29-08-18 18:51, Frank Krygowski wrote:
Hah! With my even MANlier 52-47 rings, I don't shift the rear at all! :-) Not nearly as MANly, but this reminded me of "half-step plus granny": My 1987 Trek 520 had 50-45-28 rings and 5 (or 6?) cogs, 13 to 26. So 20% differences in the rear and 10% in front allowed 10% between most or all gears. Ned |
#58
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On 8/30/2018 7:38 AM, Ned Mantei wrote:
On 29-08-18 18:51, Frank Krygowski wrote: Hah! With my even MANlier 52-47 rings, I don't shift the rear at all! :-) Not nearly as MANly, but this reminded me of "half-step plus granny": My 1987 Trek 520 had 50-45-28 rings and 5 (or 6?) cogs, 13 to 26. So 20% differences in the rear and 10% in front allowed 10% between most or all gears. Yep. That's what I'm talking about. It still works. -- - Frank Krygowski |
#59
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On Wednesday, August 29, 2018 at 11:19:03 AM UTC-7, wrote:
On Wednesday, August 29, 2018 at 12:48:22 PM UTC-5, wrote: I went for a ride with a friend last Sunday and I was spun out on my 50/11 and he COASTED by me so fast I had to wonder if he had gone electric. But you said you spin out at 75 rpm. A 50x11 at 75 rpm is a whopping 26.9 mph. Frank, Jay, me, Lou, Andy and everyone else would have coasted by you sitting bolt upright with our arms in the air giving the victory salute at the finish line. I can coast up to 26.9 mph on the trails in my town, and they are converted railroad beds so they are very gradual climbs. 1%. If I'm warmed up sufficiently I CAN turn perhaps 110 rpm for a while. With a very powerful tailwind I have ridden 5 miles on the flats at 28 mph with a 50/12. Coasting downhill and having some heavy guy flash by you motivates you to turn faster. |
#60
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Combining Ultegra Cassettes 11-34 + 14-28 - 14-34
On Wednesday, August 29, 2018 at 3:51:09 PM UTC-7, AMuzi wrote:
On 8/29/2018 12:43 PM, wrote: On Monday, August 27, 2018 at 4:51:55 PM UTC-7, Frank Krygowski wrote: On Monday, August 27, 2018 at 5:52:47 PM UTC-4, jbeattie wrote: Getting into the 50/11 is no big deal in any area with hills. I could live without it, sure, but it does have a function ... I don't see the attraction or the function. At just 100 rpm, it's 36 mph. Aero drag is really high at that speed. Non-racers (and even most racers) can't put out enough power to maintain that for a more than a short while on anything near a flat road. And on a downhill you're better off tucking in and coasting. In other words, on a downhill the power lost to air drag of whirling legs and cranks would be greater than the power put into the pedals. So it's far more sensible to coast. Instead of thinking about getting a high gear ratio, I'd think about improving the aero tuck while maintaining stability. - Frank Krygowski Frank, I was riding pretty hard yesterday and I don't believe I could reach 100 rpm. Now I don't have a cadence counter but simply counting strokes and estimating time showed me I was a lot closer to 75 rpm. Jobst rode low rpm too. Riders vary in what they find comfortable and that's A-OK IMHO. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 Very very low RPM. When I ran across him on a climb he was going up a pretty steep climb in a 48-19. When I questioned him about that he got angry. Yesterday I went up 2 miles of 6% in a 34-23 at 7-8 mph except at the very top when I was reduced to 5 mph. So I seem to be improving. |
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