I recently bought a used 2001 TT600R Belgarda with 10500 km on the clock.

I've noticed that the speedometer shows a reading that's around 7-9 km too fast compared to my GPS. That's no problem, as I know that almost all vehicles speedometers do that, incl. my 2001 Mitsubishi Colt. Something to do with EU allowing a reading that's too fast, but not the opposite.

Problem is that my odometer is running too fast too. On a 80 km ride yesterday, where both GPS and odometer was synced at the start, there was a end.difference of around 1,3 km.

The good thing about it, is that my bike has actually done a good deal lesser mileage than the clock says.

The bad is, that it's racking up the miles too fast and true fuel consumption is actually less than I thought it was.

My questions...

1. The speedometer and odometer are connected and reading from the same input, correct? So one cannot fix one independently of the other?

2. My speedometer needle jumps up and down slightly when riding. Is that a sign of something wrong? Nothing crazy, but definitely not steady. (I'll see if I can get a video up)

3. Is there any easy way of calibrating the speedometer/odometer, or should I just live with it?

I'm running 90-90/21 Heidenauer K60s on the OEM rim.

Thanks,

You're 2% of....So yeah, your bike has clocked an extra tank of gas worth riding.....In about 10.000km

I wouldn't loose any sleep over it.

Depends on how the speedometer is driven. If it is cable to front wheel the head can be recalibrated. You will need a specialist. If it is electronic off the countershaft sprocket you can get something called a speedo healer, pretty common because changing gearing throws the speedo off.

It's gear driven, can't do anything about it except get a bigger diameter tire , if I'm thinking that the right way. A tire that is 1/2"(1cm) bigger dia should be close.

2. My speedometer needle jumps up and down slightly when riding. Is that a sign of something wrong? Nothing crazy, but definitely not steady. (I'll see if I can get a video up)

Sounds like it is about time to lube the spedo cable.

3. Is there any easy way of calibrating the speedometer/odometer, or should I just live with it?

Yes and no. ( or I don't know ) For the speedo.. a lot of them you can actually move the pointer on the shaft.. making it indicate more or less..

As for the Odo. I don't really know. But there are speedo shops out there.. so they must be able to do something..

I take my cables off the bike and hang one end from a rack and keep dripping oil down the end till it is coming out the other, then chuck the top end in a drill and spin it for a bit, then some more oil till it comes out cleanish. Let it hang for a little while so the extra oil drips out then put back on the bike.

The Speedometer itself I lay it face down and fill the cable hole with oil and use a #2 square drive bit in a drill to spin for a bit to try and work the oil down in. Let it sit for a little while trying to let some oil get down inside, then dump any extra out.

I tried to take one of these speedometers apart to clean the window and paint the face white but they appear to be permanently glued together. The only way to move the pointer would be to break the housing or plastic window.

You can get speedometers recalibrated - there are some specialists working mainly within the classic car / bike world that repair instruments but I don't think you'll get it much closer than you have it at the moment.

Calibrating the odometer via gps has the problem that sometimes the gps straightlines corners and so reads less than the odometer. To be really accurate your calibration journey would have to be in a straight line - along a motorway usually. I've done this in the past and managed to get a Sigma electronic bicycle speedo (fitted to my CCM) within 1/2% of the gps reading.

When you get to that point though things like tyre wear or changing to a different brand have an effect. I could see the calibration between the Sigma and the gps drifting off as the knobbles on a Pirelli MT21 wore down. If the speedo really niggles you the cheapest way of getting a bit more accuracy would be to change to a slightly different size tyre when the current one is worn out.

For me these days as long as the speedo is good enough for me to avoid tripping cameras that'll do. I know (more or less) how much it's out by and just make a mental adjustment. The needle jumping is probably a cable that needs some oil but sometimes it can be a loss of damping within the speedo itself (storing some speedos upside down can do this). Oiling the cable is a cheaper option so try that first! I'd be wary about putting oil into the speedo head - I've known that make things worse.

Get yourself an old Guzzi and you'll then find that your Belgarda is amazingly accurate.

My Guzzi overestimates the speed and the miles by 25%.
It's an old V50 Monza and I'm told that this "feature" is normal in these bikes of a certain age.
I only use it for bimbling about on vintage runs so it doesn't really matter to me.

Thanks all. I found out that Japanese bikes usually show 5-7 % too high of a speed, so I don't think my bike is different. I think I'll just leave it as it is. But thanks for the tips and tricks.