(07-08-2020, 02:55 AM)RoadRacer2020 Wrote: Hello all
Do you have any brand suggestions when buying a speedometer?
Thank you. I need it to monitor my small progress as a road cyclist.
I use Cateye Padrones on my two bikes and bought one as a gift for a friend. Mine are wireless and simple to use once the initial settings are plugged in.
With each press of the front edge of the device, it gives you different readings for the time of day, amount of time riding, maximum speed, average speed, actual miles ridden, and has a trip meter setting.
For a first timer, the instructions can be a bit daunting but once you figure it out, it's easy. I ran into difficulty when the batteries needed changing (they last a long time, and it warns you when they need changing). Let's say I've clocked 3,902 miles and then changed the batteries. In setting it up, again, the miles are all back to 0000. Once the initial settings have been done again, then pressing the menu button will enable you to set the miles it had before the battery change. It reads: "ODO Set." It's not clear in the instructions that's what you have to do.
When I looked online for better instructions to set the last known mileage, I saw a number of people who couldn't reset their computers to the actual mileage after changing the batteries, and this was for other brands, too.
The instructions come with a chart for initial settings for many wheel sizes, but it's not accurate for all bikes. I have a fat bike with 26" x 4" tires but the overall diameter is 29". So whatever bike you have, I think it's best to do a more accurate measurement of the circumference of the wheel.
For that, I put a piece of electrical tape on the side of the tire and go by one edge of the tape for the reference point. Then I lay a tape measure out with the 1" mark next to the chosen edge of the electrical tape. Roll the bike forward beside the tape measure until the wheel had done one complete revolution, making sure the electrical tape is right at the bottom. Read the measurement on the tape measure and add one inch to get the actual circumference inches. I start from the one-inch mark because the zero point can be a bit off. Once you've arrived at the circumference inches, convert that to millimeters (We need to catch up with the world with metric tapes.) You will now have the the total number of millimeters around the tire. In the case of my fat bike, the circumference is 90.5" - 2299mm. That 2299 is what needs to be set on the computer. I would say that this method of measuring the tire circumference is needed on any bike you're going to put the computer on, regardless of computer brand.
The provided chart gives many tire sizes and their metric circumferences but it doesn't include all sizes. The nearest size it shows to my fat bike tires is 26" x 3" giving a millimeter reading of 2170mm. But mine are 26" x 4" which is 2299mm. That's a difference of 129mm or 5 3/4" and I'd be losing that with every turn of the wheel when riding. I don't know how accurate the chart is with all the tires it lists but I wouldn't trust it.
Whichever computer you get, an accurate wheel circumference measurement in millimeters will be needed. The computer measures the number of turns of the wheel to calculate both speed and distance.