trail tech vapor speedo sensor?!?

[xa-mont]

hey kids.

Kev was nice enough to give me a vapor, including the speedo sensor.

Seeing as i have already mounted a hall effect speedo sensor for the front wheel with 4 magnets, i thought i would try just rip off 3 of the magnets, put the TT sensor in the same spot and all would be good... not so.

I got it all set and it just didn't play the game. when i have the sensor away from the bike and wipe magnets past it it registers, but it seems when it is on the fork bottom and the magnets on the rotor i have no joy.

I can even swipe magnets past the sensor when it is mounted and its all fine, it's just when i have a magnet on the rotor it doesn't trigger.

here is a pic of how i have it mocked up. Anyone got any advice? do i need bigger/better magnets?

http://i29.photobucket.com/albums/c287/xacoupe/My%20SV650/2011-09-28224648.jpg

[Fight_fan]

Whats the spacing between magnet & sensor?
And if the sensor is out and u wave a magnet in front of it, is that magnet covered in ductape? If not try it n see if that makes it not work!

[xa-mont]

i have tried without duct tape (that is just there to hold it on temporarily, originally i had one glued on) and i had the sensor within a mm of the magnet. nothing seems to make any diference. it's like maybe the rotor is getting magnetised and then the sensor isn't noticing a big enough difference from the actual magnet (the rotor isn's magnetic as in able to hold metal, but it seems like the only logical explanation)

[BANDITROD]

I have always mounted my magnets to the outer part of the disc (the steel part) rather than on the alloy centre

[xa-mont]

maybe I'll give that a go.

[Redmohawk]

try mounting the sensor away from the disk a little more and adding a non metal spacer behind the magnet. I had trouble with a hall sensor picking up a magnet in a similar setup 4mm of printed circuit board (fiberglass board) solved the issue.

[OLD SKOOL BANDIT]

Hey Trav. I just ordered a couple of bolt type magnets from Acewell with 6mm dia head magnets. You're welcome to try one of those if you want. (When they arrive).

[xa-mont]

i'll see what i can do with what i have... if i have no joy, i'll take you up on that offer.

[Dynomutt]

Some of the sensors will only read when the correct pole of the magnet passes them. try turning the magnet around to show the other pole to the sensor and see if that improves the signal. You need the magnet to pass within 4mm or less of the sensor for it to get a clean reliable trace. Also use the highest number of magnets you can as the trace will be much more reliable.

[xa-mont]

well turns out it may have just been the fact that only 1 magnet requires you to get some speed up for it to start registering.

I now have 3 evenly spaced magnets on there and set my tyre size as 1/3 of its actual size and now it is playing the game well (well it is in my little trips around the back yard :P)