1998 M750 speedometer is way off. ???

[metrorollah]

Hey guys,
So I'm leading a group ride of 12 out of San Francisco, and we get to the destination and some of the guys are like "holy crap, did we have to go 95mph the whole way"... and I'm thinking damn, my speedo said 80mph tops. so i ask a few more people, and in fact, my speedo is about 15mph off.

I know it was replaced by the previous owner because the title says so, but it looks just like this one http://tinyurl.com/5wzlks on eBay that supposedly came off of a 1998 M750 ... Is it possible that its from a earlier or later model that looks identical?

1) (its a cable driven unit, so it doesnt matter what Ive done to the gearing)
2) Is it possible that its from a earlier or later model that looks identical?
3) What year did Ducati switch to a digital meter-set?
4) Are there two varieties of speedo drive ratios out there?

[Hedgehog]

The speedo on my 94 SS reads too high.  My solution was to get a BC-800 bike computer so I know what speed I'm actually going.  It's just a small thing like a wristwatch that I have to the right of my clutch reservoir.

[metrorollah]

The speedo on my 94 SS reads too high.  My solution was to get a BC-800 bike computer so I know what speed I'm actually going.  It's just a small thing like a wristwatch that I have to the right of my clutch reservoir.

"solution" 

[ScottRNelson]

The speedometer drives are all the same for the Ducatis from the 90's.  But it's rare for a speedometer to read significantly lower than your true speed.  Nearly all of them say you're going faster than you really are.  The one on my 888 is a full 20% high.  If it says I'm going 100 mph, I'm really only going about 80. 

If you really want to get it fixed to be accurate, you can take it to Palo Alto Speedometer and they can calibrate it.  One of these days I'm going to do that for my 888.

[johnster]

If it says I'm going 100 mph, I'm really only going about 80. 

My S4 is the same way. It seems at slower speeds it reads closer to actual (I think), and gets worse as I speed up. I feel like I have a pretty good "sense" of how fast I'm going, so I just sorta deal with it. 

[metrorollah]

The speedometer drives are all the same for the Ducatis from the 90's.

Thanks! My only reference is from the other venerable V-twin company - HD. They changed their speedo drive ratios a bunch of times.

1:1 ratio
2:1 ratio
2240:60 ratio

[metrorollah]

Heres a very interesting table that has Ducati presets. It really comes in handy for predicting changes in final drive gearing.

http://www.bikerenews.com/Stories_Archives/GearRpmSpeedCalculator.htm

...and actually, according to these calculations for the 749, my gauge is right. I'll bet the Japanese bikes that were riding with me are way off.  Maybe they should stop crying and get real bikes.

[Hedgehog]

"solution" 

Actually, with the BC800, I have trip time, trip distance, average speed, max speed, time, and odometer.  It's really not a bad solution.

[metrorollah]

Actually, with the BC800, I have trip time, trip distance, average speed, max speed, time, and odometer.  It's really not a bad solution.

how about tire pressure?  just kidding. im just not into bicycle wristwatches on my imported Italian stunt bike. the first time i land hard from a 12 that thing is skidding down the street or being dragged by the wires.

[Speeddog]

A mechanical speedo shouldn't read *that* high, and as Scott said, it can be fixed.

Electronic speedos started in '02 on the Monsters.
They're notorious for reading high.
However, the odo readings seem to be spot-on.

[Hedgehog]

how about tire pressure?  just kidding. im just not into bicycle wristwatches on my imported Italian stunt bike. the first time i land hard from a 12 that thing is skidding down the street or being dragged by the wires.

Are you this big a smartass all the time, or do you just reserve it for strangers on the internet?  Lighten up, d00d.  I offered you an honest answer to a problem you clearly don't have a grip on.  Say thanks and move on.

[metrorollah]

A mechanical speedo shouldn't read *that* high, and as Scott said, it can be fixed.

Electronic speedos started in '02 on the Monsters.
They're notorious for reading high.
However, the odo readings seem to be spot-on.

my determination is:

1) it is not reading high.
2) traffic is typically 80 on that road, and we rarely passed anyone.
3) all new jap bikes are designed and ridden by biatches.  

[Speeddog]

metrorollah,

Are you looking for help, or just looking to crack wise?

[metrorollah]

metrorollah,

Are you looking for help, or just looking to crack wise?

eh, i got the answer i needed on my own, but I do appreciate the helpful comments. i digress.

[clubhousemotorsports]

well even though it sounds as this mystery is solved I thought I would add something. there are different mechanical drives. one for 120/70-17 front tires oem and one for 120/60-17 front ends . the 900ss cr came with the 120/60-17 as did the smaller monsters so it is very possible he has the wrong drive. unless he has also changed his tire size to the larger tire. Or just changed the tire size but not the drive...... well you get the picture.