Speedo on my bike is incorrect?

**Gone Burger** · 5th February 2010, 10:55

Hi there.

A couple of weeks ago, I sat my resticted license on my Keeway bike. All went well and passed with no worries. However, after the test, the instructor asked me how fas I was going in both a 50k zone and 70k zone. Accoridng to me and what I was reading on the speedo, I was bang on both speeds. He told me off for going to slow as he said I was about 10k slower in each zone. Wow - so it seems that my speedo is out quite a bit.

Is this quite common? Now I actually don't know just how fast I'm going in 50k zones, 70k and 100k. I'm upping my speed a bit in each, but use to rely so much on the accurate reading for peace of mind. If a cop pulls me over and says I'm speeding, I'll get a ticket, but I'm now not sure of where that line is.

mmm Damn Korean bike (still love riding it though)

**Pixie** · 5th February 2010, 10:59

It's common.All speedometers are set to read low,some more than others.
I've fitted a cyclocomputer (available from bicycle shops) and calibrated to be dead accurate.

**sunhuntin** · 5th February 2010, 11:19

i checked mine against a 'your speed is' sign and im apparently 5k out. went past with the needle on 50, and the sign came up as 45. i was the only vehicle on the road at the time.

**motor_mayhem** · 5th February 2010, 11:37

FXR's are generally known for this problem as well. My mate got his(mine since I bought it off him) recalibrated which I think cost $200-$300.

**centaurus** · 5th February 2010, 11:51

Most bikes and quite a few cars have offset speedometers. I always thought the "your speed" signs were wrong but recently somebody that has ties with the police told me that all of them are very accurately calibrated, so every time I'm on a new car or bike I go past one of those signs to see how off is my speedo. for example, my previous car was 5-6ks slower than the speedo said; my current car is bang on at 50kph, my bike is about 6-7k slower at 50kph and about 10ks slower than the speedo at 100kph.

**kiwifruit** · 5th February 2010, 11:53

10-15% is normal

**Pascal** · 5th February 2010, 11:58

So it would seem you drive to your speedo then when sitting the test. They cannot fail you for being under the speed, can they?

**breakaway** · 5th February 2010, 12:44

Have found that most smaller bikes suffer from this issue, bigger bikes too, but not so much.

**grusomhat** · 5th February 2010, 13:09

My last bike was out by 20% some bikes are terrible I'm told. Just work out what it is and you'll be able to adapt. Some small stickers on the speedo are a cheap fix to remind yourself what speeds are what.

**centaurus** · 5th February 2010, 13:18

Originally Posted by Pascal

So it would seem you drive to your speedo then when sitting the test. They cannot fail you for being under the speed, can they?

Yes they can. I can't remember if it's 10ks or 20ks under the speed limit but it happened to me when I coverted my car license to NZ car license (basically a full license test) - doing 50 in a 70ks zone and I got in trouble for that.

**slofox** · 5th February 2010, 14:03

Originally Posted by kiwifruit

10-15% is normal

With respect, Kiwifruit, I wouldn't like to assume 10 - 15%. The checks I have done on mine suggest 7 - 8% over-read on the speedo. If I thought it was 15% I might well get my arse kicked...

**Pascal** · 5th February 2010, 14:06

Originally Posted by centaurus

Yes they can. I can't remember if it's 10ks or 20ks under the speed limit but it happened to me when I coverted my car license to NZ car license (basically a full license test) - doing 50 in a 70ks zone and I got in trouble for that.

Thanks, I should have been a bit clearer. Yes, there is the 20km/h under the speedlimit ruling. I was more concerned with the slight variation in what a normal speedo would read and being that much off the speed limit. I.e. could they ping you on the equivalent of a "dangerous riding" type of event for being under the speed limit by what your speedo is out?

**Lurch** · 5th February 2010, 14:07

My '07 SV is as good as exactly 10% over according to every "Your Speed Is" sign I've every encountered. Even the ones that I have doubled back on to try again to test a higher speed seem to indicate this.

**slofox** · 5th February 2010, 14:22

Originally Posted by Lurch

My '07 SV is as good as exactly 10% over according to every "Your Speed Is" sign I've every encountered. Even the ones that I have doubled back on to try again to test a higher speed seem to indicate this.

Is it an SV or an SVS Lurch? (Different gearing via sprocket size). Coz my SVS measures out at 7 - 8% as I said above...This from a combination of measured distance timed at a constant speed, speed carts and one check with a laser gun, courtesy of gentlemen in blue on a training mission...