Wanna See My Speedo???

[Doc Sprocket]

You SICK B@STARDS! I Meant SPEEDOMETER!!!

Sorry. Okay- Decided to see if my MTB's speedo would work for my kart- some will, some won't. I multiplied my tire diameter by PI, converted it to millimeters, and the unit accepted it. So I proceeded with the installation. Later, I will measure the actual distance the tire travels in one rotation, and use that number, a little more accurate. My test run on the speedo said max 71kmh, the GPS said 72. So I know I'm close.

Anyhow, the magnet is in a cylindrical housing with a slot in it that would fit over a spoke and retained with a screw. I drilled a 5/16" hole thru my axle sprocket, and inserted the mag with some epoxy. I then put the screw through. The pickup ziptied to a fork, so I bent up a 16ga braket and drilled holes in it for the zipties. Right now it's vise-gripped to my battery tray, I'll bolt it in later. The computer bracket was designed to clamp to a handleber, so I flattened bothe ends of a chrome pipe, and tack-welded it to my steering wheel spokes. I think later I'll move my kill switch up there. I still have to tidy up the wiring and zipe tie it in place. The tape is temporary. Oh, yeah- I had to cut and extend the sensor wires, too. The connections are soldered and heat-shrunk.

Not only does this show speed and distance, but it will save the max speed from a run, so when I'm tuning and tweaking, I don't have to stare at it while driving. I can check the peak later.
I definately recommend a mod like this. Cheers- Guys!

 

[gcarter95]

Way cool.

Question: is the piece that you have attached to the sprocket just a magnet? What is the gap between it and the sensor?

 

[Doc Sprocket]

Just a magnet in a little cylindrical housing. I likely could have substituted another magnet, but it was nothing to drill thru the sprocket, I didn't have to take it off the kart to do so. It passes the pickup at a distance of about 1/4".

 

[bajagokart]

only people from ontario would think that toystory lol here in alberta people are normal haha

 

[TOO FAST]

Alberta people normal? - God help us all

 

[Doc Sprocket]

Yup.

 

[Lynx_Genisys]

yes, us albertans are very normal...
hehehe.. muahahaha!!

 

[USApunk7]

Or if you have an iphone or something you can download and speedometer app. And what i did was get a heavy duty case and clip it to my steering wheel.Works great

 

[oscaryu1]

^ Aren't very accurate.

 

[Bluethunder3320]

I downloaded a speedometer app. I need to make a way to mount it on my avatar bike since im so afraid of either crashing or dropping my phone.

 

[redsox985]

The one on my droid, Speed View, is pretty good. It almost always agrees with the car +- 1MPH.

 

[lskelly]

did you build the speedo from scratch or buy it coz i really like it. always wondered how fast my kark went.

 

[mrfred987654321]

hey toystory 4wd! wat was the speedometer called that u used for ur go kart??

 

[devino246]

hey toystory 4wd! wat was the speedometer called that u used for ur go kart??

Any bike speedometer will work.

 

[Gokarts4Life-11]

That's awesome Toystory, I've always wanted to mount a bike speedometer to my go kart but I never figured out how.

 

[Doc Sprocket]

Any bike speedometer will work.

Almost any. The last time I actually looked into it, there were some models that could handle a go-kart-sized tire circumference, and some that couldn't. Since these units are built for bicycles, they are inclined toward bicycle-sized tires. Some simply are not programmed to accept numbers that small. For the record, I used to be an avid mountain biker, so I used my old Trek unit. If I had to guess, I'd say it's 10-12 years old.

 

[CaptCanadia]

darn, I thought I was original with the iPhone app.

 

[kendelrk]

im actually mounting a tom tom gps to mine,

 

[Doc Sprocket]

You guys are nuts. What happens when your iphone or GPS decides the vibrations are too much, and dies? Or it pops off it's mount at speed? Or you wipe the kart out?

Must be that "disposable income" I heard about...

 

[kendelrk]

No disposable income here. Actually it has just a mode to keep your highest mph. So if I put it in it's heavy armored case and put it in my pocket it'd work perfectly