How fast have you gone on your XJ?

135.... front end started wobbling.. uhm yup, lots of nice flat roads up here

 

80 mph. fast enough for me . rarely do I ever go beyond the speed limit. I keep away from the stop and go traffic by riding the backroads . this makes for a better ride in my eyes because i can enjoy the cruise which is what its all about.

Just a note:

Don't overdrive your headlights @ night.

great to know no matter what you are driving.

Be safe

 

115 on my '82 seca. Man was that fun!

 

pegged the speedo on a few occasions, that 85 mph speedo needs swapped.

 

I will be putting together a photo documentation of my speedo swap. LOOKS LIKE (can't say for certain-sure until it's done) that Yammie speedos of the same era shared the same (or very similar) guts. I got a 120mph speedo from a '79 XS off eBay and gutted it, innards look to be a straight bolt-in replacement for the Reaganometer. Stay tuned.

 

Just messing around the other day on an open clear road.Decided to twist the throttle and hunker down.Hit 105 at 8 grand and was still pulling.Redlines a 9.5.Specs say top is 127 and im sure it would do that!

1985 xj700n

 

.

A little history lesson:
When the Suzuki Hayabusa debuted, it was a 180mph rocket. Kawasaki's ZX11 was no match for it and the Hayabusa was closing in on being the first production bike to eclipse 200 mph. Kawasaki's answer was to be the ZX12, but in the same year of the 12's debut, the European Union threatened to ban them both. Bowing to pressure from Europe and elsewhere, Suzuki and Kawasaki agreed to a self-imposed limit of 300 kph (186 mph), so both the Hayabusa and the brand new ZX12 were hamstrung at the factory to a max of 186 mph.
The newer ZX14 is still subject to the same limiter.
So unless one of these three have been uncorked in the aftermarket, nobody is going 200mph on ANY of them.

And in linderman's defense, he was merely saying how fast HE had gone on a ZX-12R. He was making no claim about it's top speed potential.
270 kph translates to 167.7 mph, so his conversion is about right.

And a ZX-9R running at 280 kph => 174 mph must be a VERY healthy specimen, indeed. I had a ZX9R that would top out at just under 160mph (GPS-verified). I suspect Hyperion's speedo is a tad optimistic. That extra 14-15 mph takes a LOT more horsepower to attain. Not saying it's impossible, just curious...

 

My understanding is that most motorcycle speedos are inaccurate on the "optomistic" side above 100kph or so, mainly to keep riders safer. Your assumption fits well with that theory.

That seems to be true of MECHANICAL speedos, anyway. Not sure it today's electronic speedos are any more accurate. I was never clear on whether the sources of the inaccuracy was in the speedo itself, the pickup (speedo gears) or in the cabling in between.

...or perhaps in the overall design. The whole thing is based on the number of rotations of a front wheel that is a fixed size. But one can put slightly over- or undersized tires on a bike (90% aspect instead of 80%, for example), and TIRES WEAR. Down at the lower speeds, that probably doesn't affect the reading much, but at higher speeds when you're counting dozens of rotations per second, that error might become significant.

I don't suppose anyone knows where there's a good analysis of this?

 

RHYS,
Exactly.
Let me help you down the path of truth with a question. On what, is the revolutions per minute of your tire based upon?
hint: It involves the circumference of your tires.

Another question: What do you think happens to the circumference of your tires as you go faster and faster? Does it stay static? Is a mechanical speedometer capable of factoring for increased tire circumference?

And can a bike manufacturer control tire tolerances from lot to lot, or whether an owner buys a non-stock tire with a different profile and overall circumference?

Since i've owned a GPS, i've never ridden a motorcycle that had an accurate speedo. And the error gets worse at higher speeds, based at least partially on the thought experiment i outlined above.

At 30mph around town, most bike speedos are pretty accurate, within reason.

10 % "optimism" above 100mph is pretty much status quo. Always has been.

GPS and Radar don't depend on tire cicumference and counting revolutions of same per time unit for their measurement. That's why we believe these two devices, over a speedo.

 

The fastest I have went on my Xj650 is 119mph. When I was 16 I had a Xj1100 that I put together out of a box of parts. I had it up to 134mph one time. I quickly doubted my assembly of the bike and backed way off.

I have gone 90mph on minichopper powered by a supercharged honda 5.5. That was scary.

I had my dads Honda Vtx 1800 up to 150mph once, that big vtwin was screaming.

Before I sold my Ninja zx11 I was clocked by local police doing 173mph. I topped it out one time and got 194 mph.

All these speeds are from my gps, not the bike speedometer. Other than the one speed that was courtesy of the uniformed guy with his radar gun. As you can imagine I had a LOT of explaining to do.

 

Open two lane country road.At 70mph i nailed the throttle and was at 105 in seconds.tach was at 8,000.Could have gone faster but the popo like to hide on the side streets.I can see it hitting its rated top at 127.
85 xj700n maxim

 

I've done 195/KPH on my 80 650. Gets a little twitchy.

 

fastest i have been on my 550 was i think 75mhp so far

the bearings in my fork clamps where loose and she started to wobble and i decided to not take it any further


i guess to be correct i should say the bearings are in the neck of the frame

 

For some reason I cant get mine to go over 85mph 8O

 

You must shift into 5th gear.

 

My speedo isn't working and it only goes to 85 mph anyway but once I hit 7100 RPM's on my 750. Based on your readings I must have been at least in the 90's.

Oops...I dug deeper into this thread and it appears that 7k is right where the 85 mph speedo pegs out so I guess I only made 85-90 mph at 7100 RPM.

 

Had my '82 Seca 650 up to about 125mph (calculated from rpm) once or twice. Was actually pretty stable at that clip.

 

The 550s want to pull right to (and past) redline in ALL gears.

I now have a brand new 150mph speedometer which works great.

We gonna find out, but it will have to wait for new tires.

 

I maxed out my speedometer on an open highway in Kansas once. My speedometer ends at 135 mph, so I had to have been going somewhere between 135 - 140 mph.

All I could think about was, "If a deer jumps out in front of me all that'll be left is blood and dust."

 

I saw a thing on the Science Channel one time where they ran an F-16 into a specially hardened concrete wall at like 600 miles an hour.

All that was left was dust. Damndest thing I ever saw. The entire airframe VAPORIZED.