a good speedometer?

[2old2learn]

The challenge with an air speed meter is that it will be influenced by the general wind conditions. Imagine sitting at a stop sign with a 20mph wind blowing in your face and looking down at your speedometer and seeing it showing that you are driving at 20 mph. Now your common sense of the world would tell you that you are clearly not going 20 mph.

The best solution would be to use your smart phone. If you get the right software you should be able to just use the GPS data to show your speed and your time with very little or no data usage.

 

[butterbean]

The challenge with an air speed meter is that it will be influenced by the general wind conditions. Imagine sitting at a stop sign with a 20mph wind blowing in your face and looking down at your speedometer and seeing it showing that you are driving at 20 mph. Now your common sense of the world would tell you that you are clearly not going 20 mph.

The best solution would be to use your smart phone. If you get the right software you should be able to just use the GPS data to show your speed and your time with very little or no data usage.

All the gps speedometer apps work without a data connection. I have a spare smartphone that my dad gave me and the service has not been active for quite some time. The speedometer app recognizes around 20 different satellites. I've also had other phones without active service that speedometer apps still worked. I pretty much explained all this already.

 

[2old2learn]

Good verification butter bean. I've not tried that with some of my old off line phones. Hopefully he'll take your advice as the phone is his best option since any of us on these MAB's need to have a communication device with us for safety's sake if for no other reason.

 

[butre]

The challenge with an air speed meter is that it will be influenced by the general wind conditions. Imagine sitting at a stop sign with a 20mph wind blowing in your face and looking down at your speedometer and seeing it showing that you are driving at 20 mph. Now your common sense of the world would tell you that you are clearly not going 20 mph.

The best solution would be to use your smart phone. If you get the right software you should be able to just use the GPS data to show your speed and your time with very little or no data usage.

if the wind is that bad you're riding slow anyway. generally you can expect +-10 mph, which is no worse than most cable operated mechanical speedos

 

[butterbean]

if the wind is that bad you're riding slow anyway. generally you can expect +-10 mph, which is no worse than most cable operated mechanical speedos

A speedometer that is 10mph off is simply unacceptable to me. In fact, anything more than 2-3mph is completely unacceptable. The best way I know of comparing accuracy is by knowing your gear ratio and rpm, and finding out what your top speed should be, then comparing your actual speed to that. On my last bike, I was geared for a top speed of 32 based on another forum members educated guess of the max rpms of my engine, a 97cc four stroke minibike engine (flathead). I was able to customize my gear ratio, so I geared for a top speed of 32. Using my smartphone as a gps speedo, my top speed was consistently 32mph and I tested it several times. So I would say its quite impossible for it to have been off by more than 1-2mph. I simply would not accept a discrepancy of 10mph. Never heard of an air speed meter before, but if they're that inaccurate, I know beyond a doubt that I will never use one myself.

 

[butre]

personally I just have a tachometer and know what RPMs correspond to what speeds. I wouldn't even have that if I didn't have a bike that could break the speed limits on the main roads.

 

[butterbean]

I have a mount for a smartphone and a tachometer. Since I'm building a new bike and using an engine I've never used before, as well as different gearing than my last bike, I want to be able to compare my speed against my rpms to make sure that my top speed is correct according to my gear ratio and my rpms. Once I've ridden the bike for awhile, the speedo won't be as necessary except for at night when I can't see my tach. Just because having an accurate speedo isn't as important to some doesn't mean it's not important to others.

 

[metalzombievi]

ive been looking at the speedometer/odometers online, does anyone know of a simple reliable 2 function wireless speedometer/odometer? i dont need 15 or 28 functions. the analog speedometers dont last, ive gone through 2 in a week (broke one going too fast and the other, the odometer is stuck).i only have 1 gig of wireless data shared between 3 phones so no apps that use data can be used.

 

[butterbean]

The speedometer apps don't need data. Turn mobile data off when using as a speedo. This is my 3rd time explaining this now.

 

[metalzombievi]

is the app free? which app?