Bicycle Speedometers...???

[bmt49]

I see a number of posts talking about top speed increases above what the stock Zuma speedometer can read. I assume that some use a GPS. Have any of you considered using a bicycle computer? The Sigma line of bike computers are designed to work on wheels as small as a roller blade or as large as a 5' tall tractor wheel. I have used them on my stand up scooters with great sucess. At less than $30, they are a lot cheaper than even the most inexpensive GPS and turn on automatically while the batterys last forever. They read speed, max speed (up to 99 mph), average speed, trip distance, trip time, real time, and total overall miles. They are fairly easy to install and callibrate, though some inovation and or fabrication may be needed to make a clean install. Their total size is less than the screen size on most GPSs but have large easy to read numbers.

Here is a pic of mine mounted to my 50cc stand up EVO gas scooter. They come with a handelbar mount than easily attaches with a rubber band like o-ring. Or you can custom fab a mount to go just about anywhere.

[rydah]

i used the sigma 800 on my jog and zuma mopeds they work good, but now i going to use the GPS.

[bmt49]

I will probably end up using a combo of both. There is a lot more room and places on a sit-down o_o scooter to mount a GPS without it sticking out like a sore thumb. Whereas on a stand up scooter a GPS really stands out.

[marylandmark]

A few are doing this already. I have one on my mountain bike that is wireless that works great. I have seen them for $50 recently but sure if you shop around can get a better deal. Will make install a little easier and a cleaner look....

How accurate are they?

[bmt49]

I verify and fine tune the accuracy of mine by riding a 'known' distance, then adjusting it over and over to read as close as possible, within a few feet or less of being dead on. The streets around here are set up on a north/south, east/west grid with cross streets being 1/2 mile apart. I start with my wheel on a crosswalk line and ride till the next crosswalk. Then adjust till it is within a foot or two of being exact. I figure if my distance is correct, the speed should be right on too. When I ride with someone that is using a GPS we are very very close on readings.

I was told by Sigma that the wireless models might not work on gas powered scooters due to probable interference. It shouldn't be too hard to route the wire out of sight.

[rydah]

to me the best way to go is with the GPS watch. i found one that i am goin to use and it also have a handlebar mount like the sigma's so its all good.