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#51
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Tomorrow's Bicycle Drive?
On Monday, June 10, 2019 at 5:55:45 PM UTC-7, John B. wrote:
On Mon, 10 Jun 2019 18:02:05 -0500, AMuzi wrote: On 6/10/2019 2:52 PM, Sir Ridesalot wrote: On Monday, June 10, 2019 at 1:33:08 PM UTC-4, Tom Kunich wrote: On Friday, June 7, 2019 at 10:01:07 PM UTC-7, John B. Slocomb wrote: On Fri, 7 Jun 2019 11:09:59 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 4:31:13 PM UTC-7, John B. wrote: On Thu, 6 Jun 2019 13:15:10 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 9:11:17 AM UTC-7, Sir Ridesalot wrote: On Sunday, June 2, 2019 at 5:49:03 AM UTC-4, John B. Slocomb wrote: See https://www.youtube.com/watch?v=-9gQ1KRhesM In the narration he mentions that a 24 speed gear set, or even more, would be perfectly feasible. No wires, no cables, either. -- Cheers, John B. I can just imaging what road grit when it rains will do to those exposed bearings and interface. Can we say RAPID wear? Cheers What exposed bearings? They are sealed ceramic bearings. But again, the frame must be custom built for it. So there's no way it would ever make it on the market. Custom Frame? You mean like a MTB with fore and aft suspension? That will never make it on the market? -- cheers, John B. There is a very strong purpose for full suspension in racing and people tend to copy racers. But ravers won't use drive shafts because they are inherently very lossy. Hydraulic brakes and electronic shifting are there just to increase the cost of a bike. But the article about this "NEW" shaft drive system says that it is 1% more efficient than a chain drive. You don't think that "racers" will want a carbon fiber bike that will likely be as light as legal and 1% more efficient? -- Cheers, John B. Any testing they did must have been unloaded. You can make a lot of things look quite efficient without a load on it. IIRC the 98% efficiency of a derailleur system is reached ONLY when the gear is equal to a one to one ratio. I might be wrong about that but my understanding is that that 98% efficiency is ONLY reached with ONE particular gear. Other gears are less efficient. With the driveshaft system shown upthread I can't but wonder how it'd wear and how soon the interface of the gears would get sloppy. Plus as was also mentioned upthread, with that driveshaft it might not be too easy to do an emergency wheel swap. Cheers Yes, there's that. For bevel gears the stated '90~95%' is per set and you need two so likely closer to 80%. According to the Ceramicspeed site they tested the DrivEN system and it is 99% efficient. The entire system. -- cheers, John B. John, I'm sure it is unloaded and clean. |
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#52
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Tomorrow's Bicycle Drive?
On Monday, June 10, 2019 at 6:56:17 PM UTC-7, Ralph Barone wrote:
AMuzi wrote: On 6/10/2019 7:55 PM, John B. wrote: On Mon, 10 Jun 2019 18:02:05 -0500, AMuzi wrote: On 6/10/2019 2:52 PM, Sir Ridesalot wrote: On Monday, June 10, 2019 at 1:33:08 PM UTC-4, Tom Kunich wrote: On Friday, June 7, 2019 at 10:01:07 PM UTC-7, John B. Slocomb wrote: On Fri, 7 Jun 2019 11:09:59 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 4:31:13 PM UTC-7, John B. wrote: On Thu, 6 Jun 2019 13:15:10 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 9:11:17 AM UTC-7, Sir Ridesalot wrote: On Sunday, June 2, 2019 at 5:49:03 AM UTC-4, John B. Slocomb wrote: See https://www.youtube.com/watch?v=-9gQ1KRhesM In the narration he mentions that a 24 speed gear set, or even more, would be perfectly feasible. No wires, no cables, either. -- Cheers, John B. I can just imaging what road grit when it rains will do to those exposed bearings and interface. Can we say RAPID wear? Cheers What exposed bearings? They are sealed ceramic bearings. But again, the frame must be custom built for it. So there's no way it would ever make it on the market. Custom Frame? You mean like a MTB with fore and aft suspension? That will never make it on the market? -- cheers, John B. There is a very strong purpose for full suspension in racing and people tend to copy racers. But ravers won't use drive shafts because they are inherently very lossy. Hydraulic brakes and electronic shifting are there just to increase the cost of a bike.. But the article about this "NEW" shaft drive system says that it is 1% more efficient than a chain drive. You don't think that "racers" will want a carbon fiber bike that will likely be as light as legal and 1% more efficient? -- Cheers, John B. Any testing they did must have been unloaded. You can make a lot of things look quite efficient without a load on it. IIRC the 98% efficiency of a derailleur system is reached ONLY when the gear is equal to a one to one ratio. I might be wrong about that but my understanding is that that 98% efficiency is ONLY reached with ONE particular gear. Other gears are less efficient. With the driveshaft system shown upthread I can't but wonder how it'd wear and how soon the interface of the gears would get sloppy. Plus as was also mentioned upthread, with that driveshaft it might not be too easy to do an emergency wheel swap. Cheers Yes, there's that. For bevel gears the stated '90~95%' is per set and you need two so likely closer to 80%. According to the Ceramicspeed site they tested the DrivEN system and it is 99% efficient. The entire system. With raised eyebrow I remain unconvinced of that. Open crown/spur gear set (as opposed to wet gears in a rigid case) 99%? Hell, every race car would use them if that were true. It’s not quite a regular crown/spur set. The spur gear “teeth” appear to be made from ceramic ball bearing assemblies, so there’s minimal friction as the “teeth” slide across each other. The difference in rolling resistance between a ceramic bearing and a steel one is so slight that it requires VERY high RPM to detect. This is why adding ceramic bearings to your bike is economically silly. |
#53
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Tomorrow's Bicycle Drive?
On Thu, 13 Jun 2019 14:25:13 -0700 (PDT), Tom Kunich
wrote: On Monday, June 10, 2019 at 5:55:45 PM UTC-7, John B. wrote: On Mon, 10 Jun 2019 18:02:05 -0500, AMuzi wrote: On 6/10/2019 2:52 PM, Sir Ridesalot wrote: On Monday, June 10, 2019 at 1:33:08 PM UTC-4, Tom Kunich wrote: On Friday, June 7, 2019 at 10:01:07 PM UTC-7, John B. Slocomb wrote: On Fri, 7 Jun 2019 11:09:59 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 4:31:13 PM UTC-7, John B. wrote: On Thu, 6 Jun 2019 13:15:10 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 9:11:17 AM UTC-7, Sir Ridesalot wrote: On Sunday, June 2, 2019 at 5:49:03 AM UTC-4, John B. Slocomb wrote: See https://www.youtube.com/watch?v=-9gQ1KRhesM In the narration he mentions that a 24 speed gear set, or even more, would be perfectly feasible. No wires, no cables, either. -- Cheers, John B. I can just imaging what road grit when it rains will do to those exposed bearings and interface. Can we say RAPID wear? Cheers What exposed bearings? They are sealed ceramic bearings. But again, the frame must be custom built for it. So there's no way it would ever make it on the market. Custom Frame? You mean like a MTB with fore and aft suspension? That will never make it on the market? -- cheers, John B. There is a very strong purpose for full suspension in racing and people tend to copy racers. But ravers won't use drive shafts because they are inherently very lossy. Hydraulic brakes and electronic shifting are there just to increase the cost of a bike. But the article about this "NEW" shaft drive system says that it is 1% more efficient than a chain drive. You don't think that "racers" will want a carbon fiber bike that will likely be as light as legal and 1% more efficient? -- Cheers, John B. Any testing they did must have been unloaded. You can make a lot of things look quite efficient without a load on it. IIRC the 98% efficiency of a derailleur system is reached ONLY when the gear is equal to a one to one ratio. I might be wrong about that but my understanding is that that 98% efficiency is ONLY reached with ONE particular gear. Other gears are less efficient. With the driveshaft system shown upthread I can't but wonder how it'd wear and how soon the interface of the gears would get sloppy. Plus as was also mentioned upthread, with that driveshaft it might not be too easy to do an emergency wheel swap. Cheers Yes, there's that. For bevel gears the stated '90~95%' is per set and you need two so likely closer to 80%. According to the Ceramicspeed site they tested the DrivEN system and it is 99% efficient. The entire system. -- cheers, John B. John, I'm sure it is unloaded and clean. Well, I would assume that it was clean, after all that is the way chains are tested, and I suspect that it was loaded in the sense of having resistance to the wheel turning. After all, generating 250 watts against a freely turning wheel would be somewhat of a feat. -- cheers, John B. |
#54
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Tomorrow's Bicycle Drive?
On Thu, 13 Jun 2019 14:28:46 -0700 (PDT), Tom Kunich
wrote: On Monday, June 10, 2019 at 6:56:17 PM UTC-7, Ralph Barone wrote: AMuzi wrote: On 6/10/2019 7:55 PM, John B. wrote: On Mon, 10 Jun 2019 18:02:05 -0500, AMuzi wrote: On 6/10/2019 2:52 PM, Sir Ridesalot wrote: On Monday, June 10, 2019 at 1:33:08 PM UTC-4, Tom Kunich wrote: On Friday, June 7, 2019 at 10:01:07 PM UTC-7, John B. Slocomb wrote: On Fri, 7 Jun 2019 11:09:59 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 4:31:13 PM UTC-7, John B. wrote: On Thu, 6 Jun 2019 13:15:10 -0700 (PDT), Tom Kunich wrote: On Thursday, June 6, 2019 at 9:11:17 AM UTC-7, Sir Ridesalot wrote: On Sunday, June 2, 2019 at 5:49:03 AM UTC-4, John B. Slocomb wrote: See https://www.youtube.com/watch?v=-9gQ1KRhesM In the narration he mentions that a 24 speed gear set, or even more, would be perfectly feasible. No wires, no cables, either. -- Cheers, John B. I can just imaging what road grit when it rains will do to those exposed bearings and interface. Can we say RAPID wear? Cheers What exposed bearings? They are sealed ceramic bearings. But again, the frame must be custom built for it. So there's no way it would ever make it on the market. Custom Frame? You mean like a MTB with fore and aft suspension? That will never make it on the market? -- cheers, John B. There is a very strong purpose for full suspension in racing and people tend to copy racers. But ravers won't use drive shafts because they are inherently very lossy. Hydraulic brakes and electronic shifting are there just to increase the cost of a bike. But the article about this "NEW" shaft drive system says that it is 1% more efficient than a chain drive. You don't think that "racers" will want a carbon fiber bike that will likely be as light as legal and 1% more efficient? -- Cheers, John B. Any testing they did must have been unloaded. You can make a lot of things look quite efficient without a load on it. IIRC the 98% efficiency of a derailleur system is reached ONLY when the gear is equal to a one to one ratio. I might be wrong about that but my understanding is that that 98% efficiency is ONLY reached with ONE particular gear. Other gears are less efficient. With the driveshaft system shown upthread I can't but wonder how it'd wear and how soon the interface of the gears would get sloppy. Plus as was also mentioned upthread, with that driveshaft it might not be too easy to do an emergency wheel swap. Cheers Yes, there's that. For bevel gears the stated '90~95%' is per set and you need two so likely closer to 80%. According to the Ceramicspeed site they tested the DrivEN system and it is 99% efficient. The entire system. With raised eyebrow I remain unconvinced of that. Open crown/spur gear set (as opposed to wet gears in a rigid case) 99%? Hell, every race car would use them if that were true. Its not quite a regular crown/spur set. The spur gear teeth appear to be made from ceramic ball bearing assemblies, so theres minimal friction as the teeth slide across each other. The difference in rolling resistance between a ceramic bearing and a steel one is so slight that it requires VERY high RPM to detect. This is why adding ceramic bearings to your bike is economically silly. Certainly adding ceramic bearings to "your" bike is likely not cost effective but for a racing bike they may be worth the money as a second could well be worth considerable money if it was the winning margin in the TdeF :-) -- cheers, John B. |
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