Speedo calibration

[speedknot]

I had my 01 M750 out this weekend for the first time on the hwy.  I noticed that when I was going about 80-90mph, cars were either keeping up or slightly passing me.  This is on a stretch of road that cars normally do 70mph on.  I really didn't feel like I was going 80+.  Has anyone else noticed that the speedo might be off a bit?   I believe these are the stock tires too so I don't think the geometry of the wheel has changed.

[zarn02]

It's pretty common (read: apparently mandatory ) for bike speedos to be off. I think it's generally accepted they read 8-10% fast.

I believe the '01 750 had a cable speedo, so to fix this you'd probably have to take the gauge to a shop that works on them. If it reads off a sensor then I think you can get a nifty little magic box that will correct it.

[The Bearded Duc]

'01 750's are cable speedo.

[live2ride]

if you're ever riding next to a newer gen honda civic at night, take a look.   you'll notice that your speedo will be reading about 10% faster that his.  civics are good b/c the speedo is clearly visible if you are passing on his left.  its not where most cars locate the dash but a large digital display about a foot closer to the windshield.  very easy to see without taking your eyes off any longer than if you were looking at your rear mirror.

[speedknot]

10% off seems about right.  I guess I'm not the only one.  I'll probably just live with it since its a common issue.  I was looking for someone on the hwy to a ride along with who had a digital dash.  Just wanted to get an idea as to how much off the speedo was.

[DucRS]

The bad thing about this is the additional 10% of accumulated miles that are being tacked on to your odometer. 

[speedknot]

The bad thing about this is the additional 10% of accumulated miles that are being tacked on to your odometer. 

That's true.  So obvious, I didn't even think about that.   I guess there is no fix for this except for pulling the speedo and having it calibrated.  Probably not worth it.

[Speeddog]

The bad thing about this is the additional 10% of accumulated miles that are being tacked on to your odometer. 

Oddly enough, on my S4 (electronic speedo), the speedo indeed reads high, but the odometer is spot-on, confirmed it with GPS and various other methods....

[zarn02]

Oddly enough, on my S4 (electronic speedo), the speedo indeed reads high, but the odometer is spot-on, confirmed it with GPS and various other methods....

Weird.

And that means the inaccuracy is absolutely intentional.

[Speeddog]

Well, not necessarily.

The odometer is a digital to digital conversion, IE digital signal from the wheel sensor, 6 pulses per revolution, converted to a digital distance by the gauge.

Speedo takes that same pulse signal and converts it to a signal for the servomotor that the needle is mounted on.
I would think they do intentionally err on the high side.
I'm glad the speedo reads high, less chance of getting a ticket.

[zarn02]

I'm glad the speedo reads high, less chance of getting a ticket.

I've always assumed that the speedos read high so that people could go fast without actually going so fast.

I guess that works if nobody knows.

Me? If I know the speedo is inaccurate, I'm constantly doing rough math to try and figure out how fast I'm really going. It doesn't make me happy in any way, it just bugs the crap out of me.

[speedknot]

I've always assumed that the speedos read high so that people could go fast without actually going so fast.

Yeah but when your doing 80 and people are still up your ass, its gets a bit frustrating.  This doesn't work for everyone but I like to be passing traffic(being very observant at the same time) so I have a good idea as to whats behind me.  I hate having trucks and big vehicles sneaking up from behind.  I'm not talking about offensively driving like a psycho and in no way do I condone this type of driving, but I've always felt more comfortable passing then getting passed.

[zarn02]

I'm not saying I approve of it, I'm just saying that it's what I've always figured the manufacturers reasoning is.

[WarrenJ]

My 2000 750 does exactly the same thing.  I mount my Garmin 60 CSX on my handlebar - one of the pages shows distance traveled and current speed in large, easy to read numbers, so it becomes my speedo.  My odometer is off by a little over 10% also.  I get about 10 - 15 hours of riding time on a pair of AA batteries or a little less with rechargables.  Crude but works.

[mitt]

Randall's 620 speedo calibration was about 40% on the high side  


mitt