Why different odometer readings?
05-10-10, 04:31 PM
#26
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For crying out loud - if you really want to "see" if the bike ODO misbehaves - then go to a track and walk the bike along a lane stripe directly after reset (.1 of a mile) -then turn the bike around and walk it back - staying on the stripe - this should rule out any "rips" in the space-time continuum -but not interference from Romulans....using cloaking technology to spy on you.
You'd really have to include the rider (or an equivalent weight) to get an accurate measure.
Anyway, a good rule is to get at least three measurements.
===============
Note that I said to start counting wheel rotations. The computer would, of course, need at least two to compute speed.
Last edited by njkayaker; 05-10-10 at 04:38 PM.
05-12-10, 08:18 PM
#27
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Even with your cyclometer being a wired model, what is the accuracy of the unit? Over 22 miles a +/- .1 or .2 doesn't seem to bad. Plus the slightly different route each ride.
Chris
Chris
05-13-10, 03:56 PM
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For any given attempted measure - the wheel can be up to 80 inches short- one rotation for a 700c.
Being off 528 or a tenth of a mile for a front wheel mounted device is meaningless.
Go ahead, and make fun of me - but the stupidity displayed in many of the post warrants childish interaction.
By the way - I remember figuring about 1300 miles equals one million rotations for a 700c. One of you guys go check my math.
Being off 528 or a tenth of a mile for a front wheel mounted device is meaningless.
Go ahead, and make fun of me - but the stupidity displayed in many of the post warrants childish interaction.
By the way - I remember figuring about 1300 miles equals one million rotations for a 700c. One of you guys go check my math.
06-01-10, 10:14 PM
#30
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I think Noisebeam hit on it. My 'odometer' shows tenths, but if I cycle through functions to 'distance' it reads out in hundredths. At times it has read xx.4 (e.g.) on the odo, but xx.48 on the dist. If the OP's is similar, it might just be a function of his 'puter rounding. Or not.
06-03-10, 06:48 PM
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I was doing course measurement for a foot race with another runner/cyclist, and the specified method for route certification uses a special meter mounted on a bike (Jones-Oerth meter). The meter is calibrated versus a carefully prepared calibration course -- that takes into account the pressure in the tires. I had measured out the course previously using the shortest possible path on the MUP and marked it. When he rode following the general curvature of the path, the difference in our readings turned out to be around 30-50 feet per mile or around 0.6-1.0% difference. Everyday you ride a little different path zigging one way or the other, and it can easily cause the distance you ride to vary. That and the difference in tire pressure and load weight (maybe somedays you carry a heavy pack, others no?) changing the effective circumference of your tires will cause different mileage values from day to day.
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