XT600E 21" with 90/90-21 tire question
 

Hi!

Can anyone measure their front wheel size in Millimeters please?
Make a marking on the floor and a little on the tire and walk in a straight line until the wheel makes one complete revolution...

I need to know because the Trailtech Vapor computer has a maximum for wheel size...
Could you also tell me what tire you have on the bike... street, offroad or dual purpose so I can give it a little margin error...

I'm thinking of "HACKING" lol the Trailtech Vapor computer...

It uses ONE magnet for the speed sensor.
The magnet can either be glued of bolted onto the front brake disk .

For the bolted option you have to take one of the screws out of the brake disc and put the magnet-bolt to replace.


Now the big question... Why all this?!

The Vapor computer has a maximum for wheel size!
Then I thought... "What if I could put TWO magnets instead of ONE so it could read the speed in half the time?"

NOW, If I could set the computer for TWICE the actual size of what I have, if its within the computers parameters, and put TWO magnets I SHOULD get the same and accurate speed reading but updated TWICE as fast on the Vapor computer...

Do you feel me?!

I'm soo tired that I can't logical if the tire has to be twice or half the actual size..damn... :eek3:



Vando :smartass:

Don’t understand what you are trying to achieve !

My Trailtech happily reads at about 5mph with the magnet on the brake disk bolt. I used to change the wheel size when using different tyres but now don’t bother. Near enough is good enough for me.

I know where you're coming from - they do seem to "update" the speed a bit slowly.

Can't you just work on overall tyre diameter - 690mm for my Pirelli Scorpions - and do the calcs - 0.69m x 3.14159 (pi) = 2.1677m

Hi all!

Big Yellow Tractor

the theory is to cheat the Trailtech Vapor into "read" and show the CORRECT speed on the clock at twice DOUBLE rate!

In other words, all this is to decrease in HALF the total time the Vapor computer needs to take ONE sample from one complete wheel revolution...

Do you get what I'm trying to say? It's confusing I know! even I had to think about it for some time until I understood what it had to be done..



and thanks Piglord!

According to the size you gave me, theoretically, even if adjusting the Trailtech Vapor to the maximum which is 3999mm I would still get a 7.76% over speed error...

at 140km/h it would show 150.6 +/- 0.1 accuracy km/h....

I actually emailed Trailtech twice this afternoon. One on this subject and the other about making a custom VAPOR/VECTOR kit on their website...

The next 2 posts will be the emails I sent.

Piglord.... look at the measures I told them! I hit it straight on! LOol :rofl:

Vando :smartass:

Question and Product idea!
 

Hi!

I'm about to be one of your new costumers and I've got a question for you!

Is it possible for you to increase the maximum wheel size from 3999mm to 4200 or 4500 or something similar?
I have a great idea that might allow you to sell even more of these Vapor/Vector computers!

My idea is: If you increase the maximum wheel size just a notch it would be possible to DOUBLE the readout speed of your computers while showing the correct speed!

For example:

I have a 1990 XT600E with a complete 2002 Yamaha YZ250 front suspension that has a 21inch rim.
One revolution of the wheel with tire (if tire is 3 inches tall that would make the total go from 21" to 27in - 21+6") should be around 2150-2250 mm per revolution.

NOW, If people could setup the wheel size to DOUBLE of the actual size AND put TWO magnet-bolts or glue two magnets on the brake disk/rotor ON OPPOSITE ENDS that would that would make the computer able to show the readout twice as fast as with only one magnet and with the CORRECT speed!

That's just an example for a front 21" rim size bike model...
Most street/road bikes out there normally use 17" rims + tire so this should fit them.

But as for the rest of us who use other front wheel rim sizes this would be a big advantage and of course would be a priceless review points on your products against other brands!


Thanks and have a great week!
Vando Serpa

Question and Product service idea!
 

My other question is:

Why don't you create a special Vapor/Vector kit that has all the parts for a normal bike such as Vapor computer, power and tachometer cables, speed sensor and magnet so each person could choose each part individually and accordingly to their taste and bike model?

It would be fairly easy to do this and I bet all your clients would be more pleased with your products and services!

Options such as:
Vapor or Vector
gray or black
Speedometer sensor: CHOOSE MAKE AND MODEL AND YEAR
bolt magnet or glued-type magnet
Water-cooled or air cooled engine temp sensor: submenus with their size options

AND
An accessory menu for adding accessories that would be added to the package for their price of course!

All for one fixed price plus the accessories and shipping!

Example:

I have a 1990 XT600E with complete front suspension of a 2002 Yamaha YZ250.
I want a Vapor black computer with tach and power cables with 2002 YZ250 speed sensor and a Raptor 660 engine heat sensor(air cooled sensor).
The Raptor engine was built based on the XT600E engine and even uses the same sparkplug DPR8EA-9 which has 12mm thread diameter.

How much would cost this combo?

Thanks and have a great week!
Vando





I know... i just noticed how the email started..."My other question is:" I was going to send it in only one email but I CUT and PASTE into a second email so each question should go for the specific department lol....

Vando

Awaiting their response with eagerness...........

yes I am lol.....

Hi Bacardi,

Shouldn't you half the value if you use two magnets?

Or am i not getting it?

I think ty8igth is right double magnet should use ½ value.
Anyway all times I use push bikes computers (Sigmas) on a bike and comparing with GPSs was very accurate with just one magnet…

hey there!

no.. it has to be double the value...

think of it like this:

What happens to your stock speedo if you go from 21"(stock) to a supermoto front rim with 17" ?
It'll show a much higher speed on speedo than it actually is, right?!


With one magnet, one revolution with the correct wheel size will tell the computer the right speed!


If you put the right wheel size on the computer and put two magnets on oposite ends it will show double the actual speed.

To counter-act this you will have to set the wheel size to double while you use two magnets.



What will happen, is, it'll shorten in half the time the computer takes to show one sample of the speed AND displaying the right speed of course lol...

Did I explain myself better?


Vando :innocent:

javkap

yes, they are accurate!

my point is, I'm trying to make a way for the computer to show updated info of the speed at a faster rate.

one wheel size A with one magnet and one revolution gives you the right speed!

same wheel with size A with two magnets will read the signal TWICE in one revolution. meaning, it'll show 2 times the actual speed because the computer will "think" it has made a second revolution when it encounters the 2nd magnet when in fact it has only done ONE complete revolution!

If you go with a size B that is half the size of A with only ONE magnet it will show 2 times the actual speed.
which is similar to what happens when people go from a 21" front rim to a supermoto 17" front rim, the speedo will say it is a higher speed than it actually is.


if you go with size B and two magnets it will show 2 x2 times the actual speed. meaning that if your going at actual speed of 10mph, it'll be displaying on the computer that you're going at 40mph.

Picture in the next post!

Vando :confused1:

Here:
http://img42.imageshack.us/img42/3893/estei.th.jpg

by "HALF" I mean half revolution
http://img97.imageshack.us/img97/9079/esteij.th.jpg

If you have a 2000 mm wheel and 2 magnets wouldnt that be the same as having a 1000mm wheel?

If 1 passing of a magnet is a "tick", the "ticks" would be twice as fast with 2 magnets then 1 magnet. So, its the same as using a 1000mm wheel.

So the thing to put in the computer is "mm between each tick" (another version of wheel size - virtual wheel size or wheelsize/2)

On a 2000mm wheel and 2 magnets, if you put in the double size the computer will think that on each "tick" the wheel has turned 2000mm thus making it turn 4000mm on each real turn.. and bigger size wheel = faster moving. ?

Hi Vando,

Sorry to disagree with you on this but it is half the value......

If your actual wheel size is 2000, and you enter double the value (4000) with 2 magnets. The computer will think you have travelled 4000mm every time a magnet passes the sensor (twice per revolution) which is 8000mm rather than the 2000mm you have actually travelled.

Whereas if you half the value to 1000, every full revolution will then become 2000 having been triggered twice, which is the correct wheel size.

Let me know how you get on with it as it's a great idea to fit 2 magnets to increase the refresh rate.......i'm quite interested in fitting this unit myself.

Hope this helps.

Steve :thumbup1: