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?
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.
Quote from: Hedgehog on June 24, 2008, 10:20:12 AM
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" [laugh]
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. [evil]
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.
Quote from: ScottRNelson on June 24, 2008, 10:37:02 AM
If it says I'm going 100 mph, I'm really only going about 80. [evil]
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. :-\
Quote from: ScottRNelson on June 24, 2008, 10:37:02 AM
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
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. :o Maybe they should stop crying and get real bikes.
Quote from: metrorollah on June 24, 2008, 10:25:35 AM
"solution" [laugh]
Actually, with the BC800, I have trip time, trip distance, average speed, max speed, time, and odometer. It's really not a bad solution.
Quote from: Hedgehog on June 24, 2008, 11:17:24 AM
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? [laugh] 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.
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.
Quote from: metrorollah on June 24, 2008, 11:22:19 AM
how about tire pressure? [laugh] 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.
Quote from: Speeddog on June 24, 2008, 11:48:07 AM
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. [laugh]
metrorollah,
Are you looking for help, or just looking to crack wise?
Quote from: Speeddog on June 24, 2008, 11:58:54 AM
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.
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.
Hmmm..learn something new every day. [thumbsup]
i'm running a 120/70 on my 600m instead of the std 120/60. not sure of the direct impact of the tyre change alone, but my speedo was reading 10% low - i got booked for doing 95, thought i was doing 85 sort of thing. i now run a bike computer - much more accurate.
Most speedos read high from the factory. When you increase your tire diameter the tire makes less revolutions for a given distance than the smaller tire. 120/60 to 120/70 is a 10% increase in side wall so diameter increase.
My experience really came from mounting a set of 33" tall mud tires on my truck when it came with 195/75-15 itty bity tires. My speedo (and odometer) were off a ton . At an indicated 55mph I was doing at least 75mph. oops!
you could correct it somewhat with the correct drive but it still will not be accurate . GPS or bike speedo is best, I just check mine against the police radar and then compensate. [moto]
my 97 m900 is the same way- it reads 40 and the police radar (stationary unit- on the side of the raod with the big red display- not in car) reads 44-45. i i just ride a bit slower. it seems to work out fine.