Speedo Healer for the Tenere
 

The speedo on the Tenere is about 9% out. I was not too happy with this and when I changed the front sprocket to a 14 from 15 it got worse.
I like to know how fast I am going due to the masses of cameras in London.
I previously noted that the bike was doing 70 (GPS) when the speedo was reading 77 so some quick calcs:
70/77 = 90.9 x 14/15 = 84.8...... a 15.2% error.

I decided to fit a speedo healer at a cost of about �65 including postage. Small change when my last speeding fine was �550.

I decided to take pictures of the fitting to assist anyone else contemplating fitting one. My tank was half full when removed and did not spill any petrol at all.

First, all the grey plastics have to come off.
http://i310.photobucket.com/albums/k...y/sized_S1.jpg


Beware the small spacers, they fall out and have a mind of their own.
http://i310.photobucket.com/albums/k...y/sized_S2.jpg


Next is the rear tank bracket, again, watch the spacers, they fall out when the tank is lifted.
http://i310.photobucket.com/albums/k...y/sized_S3.jpg


Remove the front long silver bolts from under either side of the tank and also the two black plastic brackets in front of those (3x 8mm bolts each). At the same time, slip off the tube on the left side behind the long bolt. Mine did not spill any fuel. Note the rusty thread on the bracket. It was the same both sides and made romoval of one of the side panels a problem, had I left it much longer I am sure it would have seized solid and broken away from the bracket - rust inhibitor used for reasembly
http://i310.photobucket.com/albums/k...y/sized_S4.jpg


This is the hard bit. wiggle the tank up whilst keeping it roughly level and get someone to chock the rear up with something so you can get to the fuel line and electrics. The green and white plugs are simple enough to remove with the usual press catch on one side. http://i310.photobucket.com/albums/k...y/sized_S5.jpg


Now remove this clip from the fuel line and it will allow you to then squeeze the blue tabs on the fuel line and pull it off. http://i310.photobucket.com/albums/k...y/sized_S6.jpg


Now lift the tank off. This is what it looks like underneath. http://i310.photobucket.com/albums/k...y/sized_S7.jpg


Now you can access the speedo sensor cable. Its the 3 pin white one above the tappet cover, centre screen. Pull this plug apart. Care is needed when pressing the catch as it is a bit like a fish hook and the plug needs to be pushed together slightly before pressing the catch and then pulling the whole thing apart. (hope this makes sense). http://i310.photobucket.com/albums/k...y/sized_S8.jpg


Once apart it is a simple matter of inserting the male and female of the Speedo Healer lead into the now exposed female and male of the existing plug.
All that remains is to plug the new lead into the Speedo Healer, plug in the supplied extra 2 pin lead and switch (not absolutely required unless you want to know you max speed recorded) tidy it up and find a place under the seat for the Speedo Healer bearing in mind that the buttons need to be accessible (not easy if you have other bits attached under the seat) and then calibrate it to suit your set up. http://i310.photobucket.com/albums/k...y/sized_S9.jpg


This is where mine ended up. I may move it yet. I have a relay, an Autocom, an MP3 player and battery pack squeeze in too, so space is tight. This is probably my main criticism of the Tenere when you consider its intended use. http://i310.photobucket.com/albums/k.../sized_S10.jpg


The settings are (for my bike anyway) -9.1% for the speedo only and -15.2% with the smaller 14T front sprocket. Follow the instructions sullplied to program it.

I will calibrate the unit and test it against TomTom tomorrow. I'll let you know if it is any good.

OGR

Thanks Ray I will add this to the mod section.:thumbsup[1]:

I think I might have got it?
 

That's a comprehensive report, thanks Ray (I had my tank up the other day too, it's a bit of a fiddle as you say - I can see the price to check/adjust the valves being pretty high labour wise...)

As a thought - Presumably the speedo reads off the gearbox output shaft? - hence the smaller front sprocket spinning faster shows a higher top speed right?

Now correct me if I'm wrong (I'm no mathematician) but you kept the 15T front and you put a larger rear sprocket on instead (say 47 teeth), the rear wheel is now effectively turning slower for the same engine revolutions? - would than not correct the speedo over-reading?

If so, perhaps this is the problem - that the bike actually ought to be running slightly lower gearing (that is using a larger rear sprocket), but they put on a 45 tooth in an effort to keep the revs down at speed and improving MPG?

I'm going to try it next time I fit a new chain and sprockets...

xxx

Placing a 47 on instead of a 45 would do the same thing as going from 15 to 14 on the front (well about 65% of it anyway). The pickup is indeed in thre gearbox and the only way to make the speedo read correctly would be to put something like a 42 on the rear or a 16 on the front. Both these would likely make the bike struggle in top gear against a strong wind or slight incline and make off road a nighmare.

The calculation is a simple division sum. e.g.
Standard ............45T/15T = 3.00
Mine ..................45T/14T = 3.21
Your proposal ... 47T/15T = 3.13

I have now calibrated the speedo and I have programmed in an 18.5% (Yes 18.5%) correction to get the speedo to agree with TomTom. This is all very dandy and I now know exactly how fast I am going but the downside is that the odometer is now out by about 7%. After 100 real miles my odo thinks I've only done 93.

It appears that in the stock setup the gearing is correct for the odo but way out for the speedo - possibly in a vain attempt to slow us down.

Please educate me. Why would a GPS speedo reading be necessarily more correct than an OEM speedo reading? The former is being read off from a satellite which is thousands of miles above where the bike is. From what I've read so far, it seems to me that there is a general assumption the GPS reading is more accurate than the OEM's, why?

If GPS was inaccurate it would be no good for telling you where you are :)

The satalites may be a long way a way but by triangulalting the distance from up to 6-7 satalites at one time a gps unit can give you a pretty good indication of your actual land speed which is going to be quite accurate.

An oem speedo may not be necessarily inaccurate but are usually made to show a higher speed than is actually done in an effort to keep actual speeds within legal limits (as most people seem to speed by just a few mph)

I understand what you say but as DEIACCORD states they are as about as accurate as you are going to get and I have tried it over long distances in order to get as accurate reading as possible. The GPS and the speedo very nearly agree with each other to +/- 1mph at 70mph.

Over a short distance it would be innacurate as sometimes the fix can be 10m out and if the next fix it gets a few seconds later is 10m away it could record you as doing some ridiculous speed even when standing still. the better ones average the speed out over a time for accuracy.

Thats a very good point!

Ah yes, but,,


and,

The statalites are controlled by the US military, and can be made very innacurate at the click of a mouse. I'm not sure about other countries ability but in the UK we also have WASS (Wide Area Augmentation System - bet you didn't know that one, eh ??) which is a land based system that can increase the accuracy to within a few feet. This is a system favoured by maritime GPS, but devices like the Zumo also support it. The downside of WASS (being land based) is you can often loose the signal if you are 'out of sight'

So, the GPS system bases your speed on time between two points, ergo it is more accurate the faster you go. However, I belive that the calcualtion is based on 2 dimensional movement (even though your GPS operates in a 3 dimensional plane), so descending a steep hill will give you a slower reported speed that actual speed (going up hill, your reported speed will be slower than you actual speed) If you want accuracy, then a Road Book is the way to go, but then over rough terrain when the wheel is spinning (off the ground), or your wheel circumference has changed (like you've used some tread) you again loose accuracy.

The problem is that the only real way to check your speed is to measure the time between points, but this is only average. To get real accuracy, you'd need something like a laser speed detector (even so this is still only an average over a very short distance). So here we are agaim, the Police have access to the right gear, but we don't - and we're the ones who'll get shafted as a result!

All of this is academic realy, the more accurate you become, the closer you have to watch your speed.......... :signthankspin:

Waas
 

Actually we don't.... we have EGNOS or the European Geostationary Navigation Overlay Service

Nah, nah, de, nah, nah

:boxing:


:rotf[1]:

Actually, we do - it's the same bl00dy thing - different name!

I've used it in the past to give better accuracy to maritime navigation - OK, I use it to get back to to good fishing marks.

I know that, I was just trying to make out I was clever and failed...

and just a bit extra to that - when GPS first appeared selective availability (the US govt. scrambling the GPS signals) was built in to stop foreign users and naughty civvies from doing things with it they shouldn't. That 'feature' though was disabled as of May 2000 and the govt. publicly said they won't turn off or otherwise disable the system. Hence about a year ago our aviation industry finally woke up to the value of the system and started designing and trialling various GPS approaches at some UK airports. About time; the Americans have been doing it for years. NDB approach to a dodgy fading beacon at night with low cloud and strong crosswinds or a nice GPS approach in the same? No brainer. Don't get me started on the issue!
Regarding the 2D vs. 3D speed computation, interesting question. Next time I'm able I'll try some zero groundspeed autorotations, see what happens. Standard 1500 - 1600 ft/min ROD = about 18mph if my maths is correct

3 teeth extra at the back = 1 tooth less at the front. You would need a longer chain, changing the front to one less you could get away with using the same chain. Having a smaller front sprocket would also wear out quicker.

Hi Rick -

This is all true, I realised my maths was up the spout after I'd written that...

Certainly lowering the gearing causes the speedo to over read even further, although for anyone interested, once you fit an 18 inch rear wheel, I'd say the stock gearing would be pretty much bang-on - I am running 15/46 with the 18 inch rim and it only over-reads by a couple of miles per hour now...

Of course the 18 inch rim also has had the effect of gearing it higher, so i will be needing that 48T rear sprocket after all, just to get it back to somewhere near normal!

xxx

Just used this thread to help me fit the Speedo Healer I took off my old FZ6 onto my new Tenere. Very helpful.

Cheers!

As an extra to the GPS discussion, neither the Americans or the UK military use what is effectively public GPS sats, they used to use them in the beginning many moons ago (The military actually funded them) but now they have there own ones that give out a highly encrypted signal which are very accurate and which all the new drones use for navigation.

I'd be careful using a sat nav to calibrate a speedo, it's not just down to the number of sats that it can receive it's also the speed at which the unit updates it's display which is all down to an onboard timing chip, if they were that accurate the Police would use them as a sat nav unit is about a tenth of the price of the calibrated speedos that they have to use in the traffic cars.

Soooooo... these speedo healers - bearing in mind I'm now running 14/48 with an 18 inch rear wheel - God knows what speed I'm actually doing! (actually I do know, as I have my IMO fitted which is bang on for the 21 inch Michelin Desert, and the speedo is about 11mph over at a true 70mph)...

Where can I get one from and also, is there anything less than �79? on ebay... (eek!)

xxx

edit: ah found one for �55 that will do the job - http://www.speedotuner.com/ - presumably based on what n0ct0 says, one for the FZ6 will work?

Yes, the harnesses are the same. Mine came straight off my FZ6 and went straight on the Tenere. Same connectors.

Just to throw a curve ball on this thread: how do Yamaha (and all other manufacturers come to that) calibrate the speedos in the factory? I would have thought that any slight variation between the values of each speedo's electronic components might require something built in to the circuitry in order for the factory to calibrate each speedo.

Anyone fancy taking their speedo apart in order to locate the PCB mounted variable potentiometre(s)?!!

regards,
Rick

Nearly all speedometers read about 5 to 8% higher than the actual speed, probably this is done both to avoid any suit to the manufacturer in case of a fine, and to give a higer speed feeling. back in the 90s the alfa romeos speedos were about 25%!!!!! higher.

However nearly all odometers are accurate, if you install a speedo healer then the odometers becomes inaccurate, I do prefer to install a cheapo Sigma bicycle speedo on the front wheel, if will be accurate even if you change sprockets.

have fun,

j.�

I agree with the reasoning for the speedos being "optimistic" - if you fit taller gearing or larger profile tyres then you would be going faster than indicated if the speedo was spot on. (although altering the gearing wouldn't effect front wheel driven speedos - assuming your front wheel is still on the ground! )

Yep - whilst the speed can be as much as 10% out when compared to a GPS (Zumo), I've found that the odometer is only 1-2% out. Which is what got me thinking.....if the speedo is measuring distance accurately enough the indicated speed can only be out because the speedo is not counting time correctly ie too slowly(making the speedo's brain think that the bike has covered a certain distance in a shorter time ie faster!)

I suppose it is wishful thinking that the fix would be as simple as a tweek on a variable potentiometer??? Any electronics whizzos out there?

BTW, I was close to buying an Acewell speedo for my DR800 months ago prior to buying the Tenere. They look well neat with loads of useful functions and can be callibrated just like a bicycle speedo.

I'm an electronic eng. and most modern speedo are 100% digital, there are no analog parts, no potentiometer to adjust :(, in fact the optimistic reading is done inside the software of the speedo, without reprogramming it it is not possible to have both the odo and the speedo accurate, and it is almost impossible to reprogram it.

As you say, Acewell and trailtech Vapor are good alternatives, not as cheap as the bicycle ones, but they have more functions, and you can see them in the dark too.
have fun,

j.

follow ---
 

OK - I've tried to follow this thread - when my head recovers I'm sure I will adopt my original plan and fit an 18 inch rear wheel now that Jmo has shown the way forward. This should look better than the original - work better than the original and give a reasonably accurate speedo reading.

Will be looking for a little more power at sumtime in the future anyway (when funds allow) so that should take care of the over-gearing brought about by the greater rolling radius the 18 incher brings.

givit

Hi Givit - while it's true running standard gearing with an 18 inch rear wheel makes the speedo pretty accurate, you'll find that the gearing itself is now way too high (by the corresponding 10% or so)... it's fine for general road-riding, and gives a lovely relaxed top gear, but it is akin to having a six speed gearbox with no first gear!

I have had to fit 14/48 to get it back to near what it felt like with standard gearing on the 17 inch rear wheel (with the corresponding speedo error - around 10mph at 70mph) and am now running 14/50 which is really peppy, but obviously puts the speed out even further...

I think the only way to sort the speedo is with a healer unit, and then run whatever gearing you like with the wheel size you choose?

xxx

I have just fitted a 14 front and my speedo is 15% out
reads................. true speed mph
..34=...................... 30
...80=..................... 70
103= ..................... 90

Here you go, a few tools to see what happens when you change your gear ratio. Enter your sprocket ratio's.

http://ranni.altervista.org/xtx/

http://www.xt660.com/attachment.php?...5&d=1170400565

http://www.xs4all.nl/~ator0437/gc/

http://www.wotid.com/tls/files/gearing_v12.xls

http://www.4strokes.com/tech/gearing_calc.xls

http://www.gearingcommander.com/

http://www.mr2ownersclub.com/converter.htm

Jen,
The easiest thing you could do is take your bike for a ride at say 60mph on the speedo and just see what your sat nav tells you what speed you are actually going at. If you set the averaging feature to medium (I cannot remember what is called on your Garmin) it should give you a reasonable average.

Once you get the figure, the sums are fairly easy and examples are on the SpeedoHealer site. If you get stuck, just post the figures and we can sort it. The only other consideration is as to wether you want the speedo accurate or the ODO ! You cannot have both.

I say this as the only other alternative, due to the fact that you have an 18" wheel, is to do some complicated sums involving measuring the "rolling" circumference of your rear wheel when loaded and then compare that to another Tenere with a standard wheel on. Due to the tyre size being different, not just the rim size, the sums would get complicated.
Ray

Hi Ray - I'd forgotten all about this thread! I know exactly what your saying, and when the bike comes back (it's on a boat at the moment, hopefully not in the hands of pirates!) I'll have a look as you say...

I've seen a speedo healer device on Ebay for around �55 so that is probably what I'll get, although to be honest with the IMO fitted now I have a very accurate speedo/odo anyway of course...

As I recall, at a true (GPS) 60mph the bike is now reading 72-73mph... make of that what you will...

J xx

Hi Ray.

If your speedo was reading 77MPH and in fact you where traveling at 70MPH how will the addition of this gizmo make the situation better for your travel in camera mad London? I would have thought it beneficial to have an 'optomistic' speedo rathr than a 'pessimisitic', sort of a safety margin, no?

I presume when you got in trouble for speeding rather than your speedo reading 30MPH in a built up area it would have read 25MPH and that is a good safety margin for error? See my point. Now if the speedo was the other way IE reading 70MPH but actual speed was 77MPH then THAT would need addressing.

Just a thought?

I hope you have safe travel for the future.

Best wishes,

Ryland

yes but that is not legal.
manufacturers are entitled to a 10% tolerance in speedometer accuracy "the optimist way"

having a speedometer indicating a lower speed than then actual speed is illegal.

the speed displayed by your speedo can legally be up to 10% higher than your actual speed, never lower.

Hiya,

That was not my point lol. I understand what you write but the logic of the OP is perhaps odd? Better be legal at 25MPH and show on the clock 30MPH. This gives one a decent safety margin. If you see 70MPH you KNOW you are safe as you are, in reality, doing 65MPH thus not going to get a ticket.

Best,

Ryland

I wondered why my new Ten seemed to feel so slow at an indicated 30mph...
+1 for using a cycle speedo as a cheap and easy way to check accuracy. Once you know the variation, much cheaper than a speedo healer is a simple mental calculation, which has the added advantage of avoiding disrupting the odometer reading.

Mine's +10% all the time - easy maths to do on the go and my sat nav' (if fitted) is there too..

Speedo Healer ODO error
 

Hi all,
I recently fitted a speedo healer to the XTZ, I have the speedo now reading +2kmph over the indicated GPS speed at 120 kmph,
One thing I have noticed is that the odometer is way out, approximately 6km in 100 too low,
GPS indicates 100 km distance and the odometer reads 94km.
Not really a problem, but I now have to work out the fuel range indicated in comparison to actual distance required between fuel stops.

i have heard that it remains at the old setting even if you fit a healer. very strange as i would have thought it would be adjusted along with the speed reading. bit daft in a bike designed for the dirt.... it should drive off the front wheel as per the ktm's

Speedo Healer for the Tenere
 

Hi,

Just gone to 14/48 gearing on the T�n�r� and of course the readings are a mile out.

Measured against a Garmin Zumo (EGNOS on) I'm getting 30mph (GPS) against 36 indicated on the Z's clock and 15.7 miles (distance on GPS) is coming up as 17.7 miles on the clock. Bike has TKC80's fitted, std 17" rear rim.

I'm ready to fit the SpeedoHealer but I'm wondering what I'm trying to fix, the over-reading speedo or over-reading odometer. I think I'm more fussed about the odometer being accurate as I can get an accurate enough speed from the Zumo.

So, daft question, do I set the Healer to the %'age the odometer is out?

Thanks.

the photo's on page 1 don't work anymore. can anyone upload them again please?

Impossible to get the photos back on the forum as they are remotely hosted by Ray, they're only links to them on the forum, and he's obviously removed the hosted images.

However, all is not lost because I happened to have the foresight to make a copy a few years back of most of what was in post #1, including the photos! I have attached it for you.

Thank you :smilies0346: