Joined: Wed Nov 28, 2007 1:21 am Posts: 4869 Location: Seattle, WA
In the Schwinn setup there is place to set wheel circumference. Measure the distance required for the front wheel to travel one full revolution in mm and input that number into your speedometer.You should be getting a number close to 1600 mm for a 20" tire.
Remember, it's not the diameter of the tire, it's the circumference that the magnet travels. Most of the time this is the approx. circumference of the rim.
Joined: Wed Nov 28, 2007 1:21 am Posts: 4869 Location: Seattle, WA
Chris -
It is the circumference of the tire that determines the measurement. The height of the tire will determine how much ground you cover per rotation. Varying magnet and sensor placement will still yield the same number of mm per revolution. Placing the magnet closer to the outside of the wheel will cause a short duration pulse at the same interval as placing it closer tot the hub and getting a longer pulse.
It is the circumference of the tire that determines the measurement. The height of the tire will determine how much ground you cover per rotation. Varying magnet and sensor placement will still yield the same number of mm per revolution. placing the magnet closer to the outside of the wheel will cause a short duration pulse at the same interval as placing it closer tot the hub and getting a longer pulse.
I understand that...
We're saying the same thing.. Moving the magenet/sensor does have an affect on the speedometer calibration.
Joined: Sun Feb 27, 2005 12:36 am Posts: 4044 Location: In the thumb, MI
TeamHog wrote:
pghruby wrote:
Chris -
It is the circumference of the tire that determines the measurement. The height of the tire will determine how much ground you cover per rotation. Varying magnet and sensor placement will still yield the same number of mm per revolution. placing the magnet closer to the outside of the wheel will cause a short duration pulse at the same interval as placing it closer tot the hub and getting a longer pulse.
I understand that...
We're saying the same thing.. Moving the magenet/sensor does have an affect on the speedometer calibration.
Actually you're not. Rim size or location of the magnet makes no difference. The magnet makes 1 revolution with the tire regardless at what radius it's mounted. The only measurement that matters is the circumference of the contact area of the tire. There's a small "fudge factor" involved due to tire inflation & how much "squish" there is at the bottom so it's really best to play with the input number to get the speedo readout to agree with a GPS but you'll get very close with the measured circ. or by calculating it by multiplying the tire height (mm) X 3.1416.
_________________ 2 Polaris RZRs & a Dune 150. Ridge Runner--Gone. Yerfdog 3206--Gone (but you never forget your 1st!). Buggy pictures, mods, ideas, how-to's: http://tinyurl.com/8ltm8
Actually you're not. Rim size or location of the magnet makes no difference. The magnet makes 1 revolution with the tire regardless at what radius it's mounted. The only measurement that matters is the circumference of the contact area of the tire. There's a small "fudge factor" involved due to tire inflation & how much "squish" there is at the bottom so it's really best to play with the input number to get the speedo readout to agree with a GPS but you'll get very close with the measured circ. or by calculating it by multiplying the tire height (mm) X 3.1416.
You're right, I don't know what I was thinking. Too many sleepness work nights.
I was thinking of a particular pulse generation on a turbine/generator set. Similar but different....
Joined: Mon May 19, 2008 11:05 am Posts: 539 Location: Grande Cache, Alberta, Cda
You guys made my head hurt.
Just run WOT next to a vehicle and have THEM tell you how fast. Sounds a lot easier!!!!
_________________ 05' Carter Talon GSX 150 2R 39t rear sprocket (32t stock) 9g rollers (~14g stock) NGK Iridium Plug H.O. Bando Coil Dr.P Hit clutch 1500# torque spring 120 main jet @ 5000 ft elevation 42 pilot jet Uni Air Filter w/cover Drilled out stock exhaust
Users browsing this forum: No registered users and 1 guest
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum
](./images/smilies/eusa_wall.gif "Brick wall")
