-GQ- wrote:I got myself a GPS timer which also gives top speed, and we're off to Thruxton on the 17th, so I'll post here what I manage to get to on a slightly tuned ZXR geared for top speed. Should be more accurate than speedo reading too.
Would be even more interesting if the front guys were able to tell us what they get up to.
So, the fastest I went acording to my gps timer was... a mere 127mph. This was into a fair wind on the back straight (or what passes for a straight at Thruxton).
Now I'm not the fastest by a long shot, but I lapped in the low 1:30s (best lap of 1:31.4) and was in the points. Which leaves the question, are road bike speedos really that badly cailbrated? Or were the 140s and 150s helped by stong winds and rollercoaster roads?
Hmm... well the magazine tested speeds of 143 were taken with proper equiptment. I don't know what the bikes themselves were indicating, though... if you add the legal 10% over-reading allowance then you'd expect to see 157 mph which would be pretty consistant.
What speed was your bike showing, and was it topped out completely down Revitt straight?
cargo wrote:If you know the revs and the gearing then that gear commander link will tell you what your speed was.....easy really
Irrespective of any head or tail wind? Or whether it is up or downhill? Or engine bhp? Or weight? Not sure it is all that easy.
But that's my last post on top speed. 100mph around Church is way more fun and interesting than just sitting tucked in behind the screen down Brooklands and Woodham, be it at 110mph or 210mph.
All those things you mention do indeed make a difference and thats why for racing you change the gearing to get max revs for the conditions............and BHP and fat boy rider
but if your bike is really doing a given revs then the back wheel is aslo doing an exact ratio of those revs and so if you know the circumference of the wheel/tyre you have an exact speed.
Weight doesn't stop a bike getting to it's top end - just takes longer.
OEM clocks are acurate upto speed limit only as that's all they need to be after that it's on a falling scale and will vary from bike to bike.
My digital speedo shows my clocks are good upto about 100KM/H then they start to rise quicker than the digital display. The digital speedo should be acurate as it runs on the circumferance of the wheel and how many static magnetic points ( disc bolts), I would assume ZX6 and ZX10 clocks are very accurate at near any speed as they are pulse crank driven are they not?
MM!
Nothing worse than having an H and not being able to scratch it ! Living life on the edge,SuPposedly
was clocked at and fined for 143mph on my old zx4...
hit the limiter in top gear and a stock zxr ought to be doing 144... by this point the speedo will be pointing to 150-odd and the tacho to 15k+ .. most of the ones that have passed through my grubbby mitts have pulled to a smidge over 14k in top... so about 135.
zimm wrote:was clocked at and fined for 143mph on my old zx4...
Scan the ticket in! There won't be anymore arguments about top speeds then!
lol, would if i could.. but that was back in 1999.... or something
5 points and a couple of hundred quid... they were lenient, as being a courier i sorta needed my licence. (6 points already on there and 3 had just come off )
There won't be anymore arguments about top speeds then! 
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