A forum for owners of Yamaha TTR250 trail and enduro bikes!

Firestorm809 · Veteran Member

Aftermarket Speedo

robs · Senior Member

This looks similar to the trailtech speedos which come with a replacement disc brake bolt that has a magnet built into the end of it so my advice would be to superglue the magnet to the end of one of your disc bolts, this will also keep it as close as possible to your fork leg which will help the reed sensor or hall effect sensor in picking up the magnetic field. The sensor goes on the inside of the fork leg so that the magnet on the disc rotates past it.

Once your magnet is being detected you need to calibrate the wheel circumference into the speedo.. no idea how to do this on that model though so good luck! Maybe find some trailtech instructions on youtube or online and see if they are similar.

-- Edited by robs on Friday 17th of May 2019 08:05:11 PM

Firestorm809 · Veteran Member

Great advice thank you rob 👍

petenz · Super Guru

there is a bit of info here..... wireing etc...not sure if it is any good to yer...

https://www.aliexpress.com/item/Universal-Motorcycle-LCD-Digital-Speedometer-Odometer-Backlight-Motorcycle-for-1-2-4-Cylinders/32786164844.html?spm=2114.search0604.3.37.35675e6eXt0JGV&ws_ab_test=searchweb0_0,searchweb201602_8_10065_10068_10547_319_10059_10884_317_10548_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536,searchweb201603_52,ppcSwitch_0&algo_expid=cfe4d4bc-d753-4ea9-acf5-ccd4b336fc86-8&algo_pvid=cfe4d4bc-d753-4ea9-acf5-ccd4b336fc86

robs · Senior Member

This may be obvious but you get the circumference of the wheel by measuring the radius (centre of the front wheel axle to the ground in inches) then pi*r2, so if your radius is 9" then:

9*2 = 18
18*3.14 = 56.52"

You then need to work out how to get into the settings of the speedo and enter this into the wheel size setting.

Note:

Measuring the radius whilst sitting on the bike gives a more accurate reading than measuring the diameter directly since the tyre will compress slightly.

Check if the speedo uses inches, centimetres, or millimetres.

Should be as simple as that.

-- Edited by robs on Saturday 18th of May 2019 09:18:01 AM

650Katman · Member

How did you get on with this speedo? I'm considering one myself

Firestorm809 · Veteran Member

I would not bother. The sensors don't last offroad, I have gone through 2 to date and it's still not working. I would splash out and get a better built unit.

ttr steve · Super Guru

Thanks for the info, we all appreciate stuff like this smile

robs · Senior Member

I just bought a daytona nano 2. Seems pretty well built, cheaper than a trailtech, and smaller.

www.ebay.co.uk/itm/Daytona-Tachometer-Tacho-Digital-Nano-2-361-544/152833010171

650Katman · Member

Thanks for the heads up. Bicycle speedo it is then

robs · Senior Member

650katman: I've experimented with bike speedos, make sure you get one with a long enough cable (or go cableless) since most motorbike forks are much longer than your average bike so you might have a bit of trouble mounting the speedo somewhere visible.

Mateja · Member

I was tryng to find a good but not too pricey aftermarket speedo, but I had to realize that none of them matches my requirements.
So I decided to make my own dashboard with arduino and a Nextion touchscreen display, with my own sensors :) Haven’t finished yet, but the prototype is working.

Do you like the GUI design?

-- Edited by Mateja on Friday 1st of November 2019 10:30:44 AM

Base · Senior Member

12100 RPM, you sure you're riding a TTR? 😲

Mateja · Member

It’s not on the bike yet, these are just random numbers for testing ;)

robs · Senior Member

Mateja: Nice! Please release on github, would love to see how you do it!

If you're interested, I started making one a while ago that I documented here: ttr250.activeboard.com/t64772461/custom-speedo/

Shortleg · Veteran Member

Hi Mateja, I’ve thought of doing the same but never got that far, we’ll done, display looks great. Please do post more details as the design develops.
Neil

Mateja · Member

Thanks guys, I’m quite happy to see that you are interested in what I am doing.
Of course, I will share the development with you. I haven’t thought about github since I just barely know how it works, but I will give it a shot.

robs:
I had a look at your project, it’s fun to see that not I am the only one to try to accomplish something like this :)
I was thinking about 7-segment displays, but I had to realize that they are more difficult to use, also capable of much less than these Nextion display, so I went with these.

robs · Senior Member

Mateja: Great! Looking forward to seeing what you come up with.

If you're interested in the arduino code I wrote you can find it here: github.com/roobert/arduino-speedometer/tree/master/speedo-7s-driver

Here was a simpler first version in a single file: github.com/roobert/arduino-speedometer/blob/master/speedo-arduino-direct/speedo-arduino-direct.ino

It's a bit of a mess as I never finished it but you can get the general idea!

Mateja · Member

I wanted to check your codes, but I got 404 page not found error on both links :(

Mateja · Member

For those who are interested in the DIY dashboard I am currently working on, I made a project page on hackaday.io, with the title Motorcycle Dashboard.

Here's the link to it: hackaday.io/project/168272-motorcycle-dashboard

Feel free to comment your opinions and suggestions, how would you improve etc.

Mateja

-- Edited by Mateja on Saturday 2nd of November 2019 08:43:44 PM

-- Edited by Mateja on Saturday 2nd of November 2019 11:29:15 PM

robs · Senior Member

Mateja: apologies, the repository was private, I've made it public!

Will be following your project with interest!

Mateja · Member

I checked your codes, they are much more complex than what I am using right now. Did you test if this code measures accurately? Any experiences with it?

If my code won't work, I am gonna try yours.

-- Edited by Mateja on Sunday 3rd of November 2019 08:12:41 PM

robs · Senior Member

For calculating speed I believe this is what I ended up with: github.com/roobert/arduino-speedometer/blob/master/speedo-7s-driver/hall_effect_sensor.ino

I have not tested this so I can't speak to the accuracy!

I bought a cheap catseye push-bike speedo that I was going to use to clarify whether my calculations were correct..

Obviously adjust this line depending on wheel size to account for speed = distance over time: 1609344 / ( bufferAverage * 833 );

Mateja · Member

I am not quiet sure what these numbers are. Is 833 the wheel in mm? What’s the other big number?

robs · Senior Member

To be honest I can't remember, but yes they will be measurements of some kind!