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Ultimate low-spoke-count rear wheel
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Ultimate low-spoke-count rear wheel
On Oct 2, 4:31*pm, Frank Krygowski wrote:
wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: *http://www.gizmag.com/spokeless-bicy...icture/110818/ *http://www.gizmag.com/spokeless-bicy...icture/110819/ *http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Those pedals better be held in with Loctite. *Because they probably didn't spend the money on a tandem front crank. -- - Frank Krygowski There is such a thing as a pedal spanner. Stand on it to tighten the pedal then bounce a little to crack it on full whack. It never shifts from this installed position in either direction despite your unfounded fears. |
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Ultimate low-spoke-count rear wheel
On Sat, 01 Oct 2011 23:17:40 -0600, wrote:
http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: http://www.gizmag.com/spokeless-bicy...icture/110818/ http://www.gizmag.com/spokeless-bicy...icture/110819/ http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Clever. Here are the original photos, which show more detail: http://imgur.com/gSiC8.jpg http://imgur.com/hL6N4.jpg http://imgur.com/PheVI.jpg http://imgur.com/fdh9R.jpg http://imgur.com/BOjDy.jpg http://imgur.com/crUMd.jpg http://imgur.com/6kxI6.jpg http://imgur.com/T03n1.jpg http://imgur.com/vukRM.jpg -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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Ultimate low-spoke-count rear wheel
In article ,
wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: http://www.gizmag.com/spokeless-bicy...icture/110818/ http://www.gizmag.com/spokeless-bicy...icture/110819/ http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel I do like the way they glued a toothed belt to the inside of the wheel for drive purposes. That was ingenious. The rest of the design seems like making your life difficult just for fun. |
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Ultimate low-spoke-count rear wheel
On Sun, 02 Oct 2011 11:31:18 -0400, Frank Krygowski
wrote: wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: http://www.gizmag.com/spokeless-bicy...icture/110818/ http://www.gizmag.com/spokeless-bicy...icture/110819/ http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Those pedals better be held in with Loctite. Because they probably didn't spend the money on a tandem front crank. Dear Frank, The "Shimano" on the crank is upside-down, so they must have used an ordinary crank that was handy: http://www.gizmag.com/spokeless-bicy...icture/110820/ There is indeed a reason why pedals come with left-hand and right-hand threads, but this oddball probably won't be pedalled far enough to reveal the problem. Cheers, Carl Fogel |
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Ultimate low-spoke-count rear wheel
On Oct 2, 7:00*pm, wrote:
On Sun, 02 Oct 2011 11:31:18 -0400, Frank Krygowski wrote: wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: *http://www.gizmag.com/spokeless-bicy...icture/110818/ *http://www.gizmag.com/spokeless-bicy...icture/110819/ *http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Those pedals better be held in with Loctite. *Because they probably didn't spend the money on a tandem front crank. Dear Frank, The "Shimano" on the crank is upside-down, so they must have used an ordinary crank that was handy: *http://www.gizmag.com/spokeless-bicy...icture/110820/ There is indeed a reason why pedals come with left-hand and right-hand threads, but this oddball probably won't be pedalled far enough to reveal the problem. Cheers, Carl Fogel It's for speed of assembly. With the bike held in the air by the seat pin, the pedals are threaded on together by turning the cranks backward. It's a simple single operation used to cut production time. A pedal spanner is applied with the wheels on the ground and cracked tight, leaving the cycle safe to operate. The direction of thread is unimportant, a pedal may still come off if it is not cracked tight. I have seen this happen with steel axles in steel cranks. |
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Ultimate low-spoke-count rear wheel
On Oct 2, 3:13*pm, thirty-six wrote:
On Oct 2, 7:00*pm, wrote: On Sun, 02 Oct 2011 11:31:18 -0400, Frank Krygowski wrote: wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: *http://www.gizmag.com/spokeless-bicy...icture/110818/ *http://www.gizmag.com/spokeless-bicy...icture/110819/ *http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Those pedals better be held in with Loctite. *Because they probably didn't spend the money on a tandem front crank. Dear Frank, The "Shimano" on the crank is upside-down, so they must have used an ordinary crank that was handy: *http://www.gizmag.com/spokeless-bicy...icture/110820/ There is indeed a reason why pedals come with left-hand and right-hand threads, but this oddball probably won't be pedalled far enough to reveal the problem. Cheers, Carl Fogel It's for speed of assembly. *With the bike held in the air by the seat pin, the pedals are threaded on together by turning the cranks backward. *It's a simple single operation used to cut production time. *A pedal spanner is applied with the wheels on the ground and cracked tight, leaving the cycle safe to operate. *The direction of thread is unimportant, a pedal may still come off if it is not cracked tight. *I have seen this happen with steel axles in steel cranks. Assembly speed? Maybe so, or at least that might be one consideration. At what point does the chain get put on? I've seen a Campy steel axle pedal come out of a Campy alu crank arm in use-- a new pedal and crank, maybe 20 miles max into the first ride, and the pedal was not, according to the post-accident investigation, tightened "tight". It was a right-side pedal btw. When I used to rent track bikes at Alkek Velodrome, one "overseer" took me to task for using the leverage available in the pedal wrench. Um, corrected later in the infield while supervision was supervising elsewhere, thank you very much. I always just figured the pedal spanner had an unusually long handle on it, compared to the other "hand tools" for good reason. Only one of which "good reasons" was getting tight pedals off g. After Reading Jobst, I would think that, while a very tight pedal spindle might still fret a crank (arm) (g) around the pedal eye, it should fret less than a looser one. --D-y |
#9
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Ultimate low-spoke-count rear wheel
On Oct 3, 10:55*am, " wrote:
Assembly speed? Maybe so, or at least that might be one consideration. Dear D, Reversed pedal threading has nothing to do with assembly speed. "In 1900, the Wrights announced a 'bicycle pedal that can't come unscrewed.' Pedals were mounted to the crank by threaded posts. On early bicycles, both posts had standard right-hand threads. As the cyclist pedaled, the action tended to tighten one pedal and loosen the other, with the result that one pedal kept dropping off the bike. Wilbur and Orville used right-hand threads on one pedal post and left- hand threads on the other so the pedaling action tended to tighten both pedals." http://www.wright-brothers.org/Infor...t_Bicycles.htm That's why tandem cranks are reversed on both sides. If you pedal a normal crank backward (that's a tandem crank), both pedals would tend to unscrew. If you want to see a horde of posters slowly working through the details of the light bearing friction (which isn't the problem) versus the heavy precession effect (which is the problem), see this thread: http://www.bikeforums.net/archive/in.../t-381225.html When bicycles first appeared, left-hand pedals kept falling off . The Wright brothers reversed the thread ion the left-hand pedal n 1900 and fixed the problem. Since tandem cranks are reversed, they have both pedal threads reversed. The bearing friction would seem to work in the opposite direction, but it's so light that it doesn't matter--it's the enormous effect of precession that tends to unscrew a normally threaded left pedal. Sheldon explained this: Pedal Threading Direction The right pedal has a normal thread, but the left pedal has a left (reverse) thread. The reason for this is not obvious: The force from bearing friction would, in fact, tend to unscrew pedals threaded in this manner. It is not the bearing friction that makes pedals unscrew themselves, but a phenomenon called "precession". You can demonstrate this to yourself by performing a simple experiment. Hold a pencil loosely in one fist, and move the end of it in a circle. You will see that the pencil, as it rubs against the inside of your fist, rotates in the opposite direction. Ignorant people outside the bicycle industry sometimes make the astonishing discovery that the way it has been done for 100 years is "wrong." "Look at these fools, they go to the trouble of using a left thread on one pedal, then the bozos go and put the left thread on the wrong side! Shows that bicycle designers have no idea what they are doing..." Another popular theory of armchair engineers is that the threads are done this way so that, if the pedal bearing locks up, the pedal will unscrew itself instead of breaking the rider's ankle. The left-threaded left pedal was not the result of armchair theorizing, it was a solution to a real problem: people's left pedals kept unscrewing! I have read that this was invented by the Wright brothers, but I am not sure of this. Note! The precession effect doesn't substitute for screwing your pedals in good and tight. It is very important to do so. The threads (like almost all threads on a bicycle) should be lubricated with grease, or at least with oil. http://www.sheldonbrown.com/gloss_p.html Cheers, Carl Fogel |
#10
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Ultimate low-spoke-count rear wheel
wrote:
On Oct 2, 3:13 pm, thirty-six wrote: On Oct 2, 7:00 pm, wrote: On Sun, 02 Oct 2011 11:31:18 -0400, Frank Krygowski wrote: wrote: http://www.gizmag.com/spokeless-bicycle/14216/ Intricate gearing: http://www.gizmag.com/spokeless-bicy...icture/110818/ http://www.gizmag.com/spokeless-bicy...icture/110819/ http://www.gizmag.com/spokeless-bicy...icture/110820/ Cheers, Carl Fogel Those pedals better be held in with Loctite. Because they probably didn't spend the money on a tandem front crank. Dear Frank, The "Shimano" on the crank is upside-down, so they must have used an ordinary crank that was handy: http://www.gizmag.com/spokeless-bicy...icture/110820/ There is indeed a reason why pedals come with left-hand and right-hand threads, but this oddball probably won't be pedalled far enough to reveal the problem. Cheers, Carl Fogel It's for speed of assembly. With the bike held in the air by the seat pin, the pedals are threaded on together by turning the cranks backward. It's a simple single operation used to cut production time. A pedal spanner is applied with the wheels on the ground and cracked tight, leaving the cycle safe to operate. The direction of thread is unimportant, a pedal may still come off if it is not cracked tight. I have seen this happen with steel axles in steel cranks. Assembly speed? Maybe so, or at least that might be one consideration. At what point does the chain get put on? I've seen a Campy steel axle pedal come out of a Campy alu crank arm in use-- a new pedal and crank, maybe 20 miles max into the first ride, and the pedal was not, according to the post-accident investigation, tightened "tight". It was a right-side pedal btw. When I used to rent track bikes at Alkek Velodrome, one "overseer" took me to task for using the leverage available in the pedal wrench. Um, corrected later in the infield while supervision was supervising elsewhere, thank you very much. I always just figured the pedal spanner had an unusually long handle on it, compared to the other "hand tools" for good reason. Only one of which "good reasons" was getting tight pedals off g. After Reading Jobst, I would think that, while a very tight pedal spindle might still fret a crank (arm) (g) around the pedal eye, it should fret less than a looser one. --D-y thirty-six, When do you think the pedals are installed? New bikes are shipped from the factory with the pedals not installed, to reduce the size of the packaging. I've never seen a bike shop mechanic install pedals in the way you describe - all the ones I've seen install one pedal at a time. My years in the shop happened a long time ago, though. Any current shop mechanics want to weigh in? Thanks, Kerry |
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