Sprocket ratio change & Speedo readings.
 

If you want to correct your speed reading after a sprocket ratio change. I recommend fitting a Speedo healer, this little control unit plugs directly in the Yamaha speedo wiring & requires a ignition live wire to the Speedo Healer. It takes about 20 min to fit & set up.

I now have a 100% accurate speedo after my ratio change.

http://www.amcmotorcycles.com/ Look under Instrumentation.

http://www.speedohealer.com/eng/intro.htm

http://cgi.ebay.com.au/Speedo-Healer...QQcmdZViewItem

A new Speedo Healer is out, version 4.

http://www.bikersdiscountstore.co.uk...do_Healer.html

Is the speed not determined from the front wheel , in which case sprocket ratio is irrelavant?

Kev,

As i have fitted a smaller front sprocket would it be advisiable to fit one of these??

Cheers

WB

unless you wanna have your bike runs virtually faster :nos:

i can recommend this. It has 2 memory banks for storing different wheels/sprocket size. Easy to install
http://www.speedohealer.com/your_pic...4/tutorial.htm

Yes WB I will recommend one of these any day they are great tools, you set your speed to your GPS or road markers to get your speedo to read 99% of the true road speed.

I am surprised that only a hand full of us run them.

Kev

Just ordered the V4 one this afternoon.

Hopefully should receive it at some point next week

Cheers

WB

Here in south africa, I dont think we will get this device :( Does it fix both your speed, and distance? how does this device do this?

The device intercepts the speed signal from the gearbox & can change the signal inpulse to run faster or slower which will effect speedo & trip meter readings.

It can recall your top speed at a push of a button, as I said before it's a great little tool.

Do I read correctly that it does not change the normal Odometer. Just the trips.

I now have the 46 tooth rear sprocket fitted and notice about 5% difference in the Mileage readings before and after would this fix this or just the speed and trips??:smilies0337:

Thanks again Kev, How is Autumn???:111:

A Speedo Healer will correct all 3, speedo, trip meter & odometer. As they all get there signal from the one sender which the Speedo Healer intercepts.

No worries mate, the speedo healer will sort your sprocket change.:evil5:

I fitted one also last week, (went +2 at the rear) it is pretty straight forward to install, I also corrected the assumed 5.5% factory false reading..

Someone correct me if I'm wrong here, but most bike speedos are optimistic (ie: they over-read) and going up 2 on the rear (ie lowering the overall gearing) will make it even more optimistic. You need to raise the overall gearing to "fix" the assumed optimism.

I don't think that you would get a different reading if you change the back sprocket, because the front is still doing the same amount of revolutions.

If you add three teeth to the rear that is the same as 1 less at the front, you would need a new chain because of the size of the rear sprocket, and it would make the engine more lively because it will be easier to turn the back wheel, same has riding a push bike the larger the rear sprocket the easier it is to pedal

Unfortunately you do get a different speedo readings if you change the rear sprockets, front sprocket or tyre/ wheel size.

The XT gets its speedo pick up from the gear box out put shaft by the front sprocket.