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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
On Mon, 8 Sep 2003 13:49:52 -0500, johnfoss wrote: So I'm fine with a nice, median number. That's why I would be interested to hear the results people are getting, in the form of circumference numbers, listed along with those other factors mentioned above. If several people do this, the rest of us (the lazy ones) may be able to make pretty accurate extrapolations from that data. Even though I don't own a Coker yet, I volunteer to process the data (if enough comes in) into a formula that estimates rollout from A. rider weight, B tyre pressure and C tread wear (as an estimated percentage). Please state also whether the rollout is 1) unloaded and in a straight line, or 2) loaded and in a straight line, or 3) from a ridden distance so that wobble is included. You may want to include additional data (speed, surface type etc) but it may be overkill. Data are best posted here (as opposed to sent via e-mail) so that they are publicly available. The few that have been posted in this thread need no repeat but you might want to elaborate on them. As for wobble, this is another factor that varys not only with the individual, but I think also with the speed you are riding. I'd rather not factor in wobble, unless it happens automatically as part of the calibration method. That is stinky. That way you will have wobble in some data but not in others, depending on how it happened to have been measured. Contamination of the data set! Klaas Bil - Newsgroup Addict -- If the crank is moving then it really sounds as if it's loose. - onewheeldave trying to pinpoint the cause of a clicking crank -- Klaas Bil - Newsgroup Addict ------------------------------------------------------------------------ Klaas Bil's Profile: http://www.unicyclist.com/profile/3442 View this thread: http://www.unicyclist.com/thread/27640 |
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PING ALL COKEURS: Share your rollout data (Was What circumference did
Cokerhead writes:
OK, Here's my scientific method. I stole data from other people. I entered it into my computer. I adjusted from time to time, based on observations from other road markings and bicyclists and car odometers. I am happy to get within 2% accuracy(I usually ere on the fast/long side). I give myself a break and don't try to discount for wobble(I don't wobble as much as some) To add to Mark's methods, here is what I do: I rode over a 'measured mile' on a bike path and counted the revs, getting about 577. I made sure the cycle computer gibed with that. This takes into account the wobble of my riding. Here are the calcs: Wheel height: 35.75" Theoretical revs per mile [5280/(35.75 x pi)] = 564 Actual revs per measured mile: 577 Wobble effect: 2.3% (I ride an extra 23 feet for every thousand revs) This means I'm riding an extra 115' or so every mile. If you factor your measured mile (revs per mile) into the cycle computer, you get a truer idea of your actual speed than if you just go by circumference. Now to answer the questions: A:230-245lbs(lately) 190-195 B:45-50psi 50-55psi C:Varies from ride to ride I did a rollout(unloaded) long ago and don't remember the number Right now I have 281 entered into my cyclometer and I'm happy with that number. I can't recall the # I entered. It's certainly around that one. -Mark David |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
2776mm
A. rider weight 170 lb B tyre pressure 50 psi C tread wear (as an estimated percentage) 50 3) from a ridden distance so that wobble is included. Distance is 3 revolutions, averaged over multiple runs ---Nathan |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
2782 mm calibrated via 0 UPD known distance 2.65 mile ride -- duaner - - ------------------------------------------------------------------------ duaner's Profile: http://www.unicyclist.com/profile/4297 View this thread: http://www.unicyclist.com/thread/27640 |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
duaner wrote: *2782 mm calibrated via 0 UPD known distance 2.65 mile ride * FYI: that's with the tire at 32psi and moderately warn down (about 1/2 of it's life), and I weigh 150lbs -- duaner - - ------------------------------------------------------------------------ duaner's Profile: http://www.unicyclist.com/profile/4297 View this thread: http://www.unicyclist.com/thread/27640 |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
Can't remember the exact figure I used, but my view is that a 1/2 inch error on a 36 inch diameter = 1.3%. That's more accurate than my car speedo or scooter speedo. My weight fluctuates; the weight of water in my Camelbak fluctuates; the tyre pressure varies throughout a ride. I reckon if the tyre's a bit softer, then the mileage and speed are 'rounded up', but pedalling is a bit harder, so it's self-compensating. Then again, I only use the computer for comparing my own performances. -- Mikefule - Roland Hope School of Unicycling Why does no one shout, "Where are your steering head bearings, derailleur mechanism and your other inner tube?"? ------------------------------------------------------------------------ Mikefule's Profile: http://www.unicyclist.com/profile/879 View this thread: http://www.unicyclist.com/thread/27640 |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
These rollout posts are fragmented and I don't want my post to get lost; it's in 'this thread' (http://tinyurl.com/mru8). Basically I argue in detail for eliminating all rider characteristics from the rollout that we share. -- U-Turn - Mounting a Revolution Weep in the dojo... laugh in the battlefield. 'Strongest Coker Wheel in the World' (http://www.unicyclist.com/gallery/albup39) -- Dave Stockton ------------------------------------------------------------------------ U-Turn's Profile: http://www.unicyclist.com/profile/691 View this thread: http://www.unicyclist.com/thread/27640 |
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PING ALL COKEURS: Share your rollout data (Was What circumference did you ent...
-Originally posted by johnfoss- Because we are the nerds, not them. Very well placed post, John! We can get pretty nerdy over a millimeter or two sometimes. For my 2 cents worth on the rollout though...when i first fitted a computer to my coker, i did an unmounted rollout...just pushed it down the road and took a measurement. I knew it wouldn't be very accurate, but i couldn't figure out any way to do an accurate rollout mounted. Then i spent several days making small adjustments after riding on routes of "known" distances until the computer reading matched what i thought the distance was. Not very scientific, i know...you've still got the argument of "how did you arrive at the known distance?" Anyway, the number i arrived at was 280...my cheapo computer only accepts cm, not mm. _______________ A man with a watch always knows what time it is... a man with two watches is never quite sure. -- Chuck Webb I live in my own little world but its ok...they know me here! ------------------------------------------------------------------------ Chuck Webb's Profile: http://www.unicyclist.com/profile/1450 View this thread: http://www.unicyclist.com/thread/27640 |
#9
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PING ALL COKEURS: Share your rollout data (Was What circumference did
On Tue, 9 Sep 2003 11:38:07 -0500, U-Turn
wrote: Comments? First of all, I respect your opinion which you have so carefully phrased. Thanks a lot! From the data that people post I hope to be able to assess a typical (or 'best') Uncalibrated Rollout. And I will include that number as a key result. Only I don't like the name. Uncalibrated sounds as if no care has gone into it, e.g. you just take the nominal 36" and multiply by pi. I'll try and think of another name. He or she can easily determine a single multiplier that takes into account of wobble, weight, typical tire pressure, etc.. Call this multiplier the -RCF-, or *Rider's Characteristics Factor*. I wouldn't say that the effects of wobble, weight etc can /easily/ be determined. Indeed, that is precisely what this little project is about. But I like your way of reasoning and ideally the results of my endeavour should include the Uncalibrated Rollout (by whatever name) and a formula that calculates an estimated RFC from the parameters mentioned in my 'original' post. I won't have time, BTW, to do the math until after next weekend. Klaas Bil - Newsgroup Addict -- If the crank is moving then it really sounds as if it's loose. - onewheeldave trying to pinpoint the cause of a clicking crank |
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