Too optinisic speedo??

Since I bought my Cat the speedo cable snapped at the wheel end. I don't know if it was ever changed or lubed so no problem I ordered a new one of ebay. Since putting the new cable on it looks like and feel that it is a bit optimistic. Doing 30 mph feels more like 25 and 40 more like 30. Has anyone experienced anything like this?
My last bike was GSXR 750 so I was sitting closer to the ground and bit more forward. maybe different bike gives different sensation of the speed.

Did the test with ride tracker on my iPhone going to work today and the tracker says that the distance covered is 5.2miles and the odometer 5.5miles. I checked on the google maps and that shows 5.2miles too.

Any advice would be appreciated.

Thanks

Kam

It does over read, mind you at 30 it is supposed to be fairly accurate. The distance check you did does not surprise me. It isn't only the Thundercat, most speedos aren't right.

My new Tracer is also optimistic and that is all electronic, it claims I'm going faster than I actually am (compared to a SatNav) it also says I'm getting a better MPG than I am too.

Think you may be right about the riding position and speed sensation, I'm now riding upright and 50 feels like 30

A way to tell is by going into 4th gear and using the revs. E.G. 6k revs in 4th gear is 60mph, 4k revs is 40mph etc. I believe this is fairly accurate.

Mike - I did what you suggested this morning and it was reading 2-5mph over 40, 50 and so on.
My final test will be with a satnav and phone speed app.

after all it is better for the speedo to show higher speed. This way I won't receive any speeding fines

Just a thought. Have you got standard size tyres on?

I didn't think of the tyres. It should be 120/60/17. I will check tomorrow moring, but what size would it have to be to boost the speed on the clock? I guess smaller in order to turn quicker. So if its 120/50/17 that would be it. Right?

Right I'm not a maths genius or physicist BUT
if your running 120/70 instead of 120/60 (standard) your circumference will be greater (greater % of profile on width) vica versa with 50 profile tyres
What I'm not sure is which way this will change speedo reading.
I think some folks do run 70 profile so maybe they could compare, also some people may only run a 16" front wheel.
Not much help sorry but maybe a step in the right direction.
Irun 120/60 x 17 and next time out will test the 4th gear scenario and let you know

2 to 5 mph over at those speeds is with in legal limits, and would be no different than almost all speedos on any vehicle. Very few speedos read true unless they have been set up, ie police speedos and tachographs.

Catnapper wrote:Right I'm not a maths genius or physicist BUT
if your running 120/70 instead of 120/60 (standard) your circumference will be greater (greater % of profile on width) vica versa with 50 profile tyres
What I'm not sure is which way this will change speedo reading.
I think some folks do run 70 profile so maybe they could compare, also some people may only run a 16" front wheel.
Not much help sorry but maybe a step in the right direction.
Irun 120/60 x 17 and next time out will test the 4th gear scenario and let you know

May speedo appears to be the same 2-5 mph over in 4th

Thank you all for your comments. Because I have new set of tyres I will keep them on and ride knowing that I am under by 2-5mph to what speedo is showing.
Next set of tyres will be 170 size