VFR Top Speed is ????

91 mph in a speedo is fast enough. I hope nobody puts up one of those requests for pix... Although it would not come as a complete surprise...

 

145 on my 1992 vfr750

 

Got 170mph with a pillion passenger. Girl of about 50 kilos. Bloody audi started to overtake another car in front of me. Glad i just cleaned my brakes. Never attempted a second run. And soon after that i hit some pot on the road so my front wheel is slightly fractured. After 100mph bike starts vibrating badly. Cant be fixed. Need a new wheel. So expensive... But may be it is a life saver as i am limited to 100mph now

 

170 with a passenger? On a bike limited to about 155? Come on, now...

 

170 indicated would still be 153 true speed, and with a passenger? even a light girl like that? sounds like a story to me (or at least a smaller than stock front tire to really throw the speedo off). I also don't think I'd want to ever ride with someone willing to go those speeds with a passenger... unless both were wearing race-grade leathers and on a closed course.

 

I do not know how the speedometer operates, i do not know whether the actual speed is lower than the one indicated but i saw that we went over 270kmph(which is 167mph) when i noticed audi faar away infront of us indicating that it was going to overtake a car. Thank you audi driver for showing indicators at all on a motorway.
I am not a maniac on the road, i drive like an average bike rider, slightly over speed limit, overtaking slowly moving cars. That girl asked me to give her a ride at the maximum speed possible. I told her it was going to be that fast. I told her that everything can happen on the road. She agreed to that. After all She enjoyed the ride and asked me for more. I said no, i was scared enough of those speeds myself. And who said that those bikes are limited to 150? I was on 4th gear and was gaining speed. No vibes at all. Just a bloody wind. If not audi I would go faster. It is VFR VTEC 800, not 750.
Sorry for my english, it is far from perfect

 

Kudo's for not doing it again. I totally understand the temptation of a girl asking for a good time.....

The gearing on the bikes means that if you could wring it fully out in top gear, it would only do about 155-160mph before you'd be at redline in 6th gear. The math I did a while back gave a 145mph true top speed:

rpm: 12 krpm
primary drive ratio: 1.93:1
6th gear ratio: 1.03:1
front sprocket: 15 teeth
rear sprocket: 45 teeth
rear tire: 180/55R17 (77.8 inch circumference)

which all worked out to 147mph (235 kph or so). Usually the speedo is 10% off (high), and would have said around 250-260kph. On the 6th gen bikes I don't remember if they have a transmission speed sensor or use a wheel-speed sensor. but even with a tranny speed sensor, you'd need to be over redline in top gear to make the ECU think it was going that fast (or it was just plain confused, the speedo is known to be very optimistic at those speeds).

 

is this common for a bike to show speed greater than it really is? Is the story the same with cars?

 

very common on bikes, most cars are very, very close (but will usually be a touch optimistic). If the speedo reads high, you can't claim that you didn't think you were speeding, and putting the liability for the ticket on the manufacturer. But then every car I've driven (aside from my audi) has been dead-on. The audi reads about 2-5% fast, but that could just be the tires.

 

Could definitely be tires. My Audi is spot on with the GPS to beyond 100mph. My VFR reads ~8% fast, my Triumph Scrambler is <2% fast, my Trophy is ~5% fast (all compared to the same GPS). As far as the VFR goes, it is plenty fast. I've not had an opportunity to go beyond ~120; but I did see 155 indicated on a 2001.

Something I thought I'd mention - a couple things actually - first is that aerodynamics is the PRIMARY determining factor with regard to top speed. Weight has almost nothing to do with it assuming the path is long enough. Secondly, it is entirely possible that the aero drag is actually lower with a passenger than without. I don't know this for a fact; but the primary contributor to the aero drag is the inability of the aero envelope to 'close' cleanly behind the bike/rider. I suppose it is possible that a passenger corrects this.

Only hypothesizing; but it's possible.

 

Yeah, I was surprised that the new audi was off (2-3 mph at highway speeds). Although this is vs. the roadside radar, not a GPS (so it could be tuned high to more aggressively warn drivers to slow down).

My math above was ignoring aero, given that there's a mechanical limit due to gearing, tires and redline. My math could be wrong, however (wouldn't be the first time).

I can definitely see a passenger, especially a small one like that actually helping by filing in the void right behind the rider, and providing a better taper down to the tail. Bike aerodynamics are pretty rotten, vs a car.

edit: 2006 Audi A4 Avant 2.0T, chipped -> sleeper speed demon.

 

After all these talks I have to try it again. Reach the maximum speed possible. Without a passenger of course. Our motorway stretches are straight and long enough for this experiment. If i go early in the morning when there are no cars I can get maximum out of it. And on board camera will fix it. The only problem as i already mentioned is my front wheel. It will take some time before i can afford to buy it. Jeeez, how badly i wanna do it now

 

enh.... Save it for a track day a super-speedway (if you have any over there, NASCAR unfortunately gives us reason for plenty to exist here), or a trip to Germany. I just don't think it's that relevant. Very few people can legally go even remotely close to these speeds, and it's really not all that applicable to what makes these bikes great bikes. (they're not hyabusas).

 

speedometer reading comes directly off a sensor on the front sprocket on vtecs. it has absolutely nothing to do with the front tire. maybe a change in rear tire size difference, and more than likely a sprocket kit. i am now red lining 6th, with my one down kit.
as far as this happening in fourth, while i can appreciate a good story, this is complete bullshit

 

A one-down front sprocket, redlined, is 137mph, CandyRedRC46. That seems very plausible. But 130mph in 4th? not likely.

 

at 178 indicated, im actually doing 156 on gps now

 

Then I certainly have my math wrong. (goes and checks), yes I have 6th inverted (28/29 vs. 29/28). But I also have a different sprocket setup. Are the 6th gens 16/43 or 15/45?

 

Guys, I have no intentions of lying to you, I am possible wrong about 4th gear, that happened a while ago. But I am positive that i've seen a 270 0n my speedo. But if you guys say it is far off the real speed I trust you. After all, the maths behind this is rock solid. Even though i did not get how the actual calculation was done Our race course is small and will not allow to reach those speeds. Motorway is the best call. 2 bikers go together, one pulls over and another one travel a few kms to check for a police. If none, the race starts. And early in the morning there will be no cars either. I have no intentions to cause any danger to anyone on the road, especially to myself. How accurate a police radars? I need to get one to measure the speed? Or how accurate are GPSs?
To woody77: What is the formula for calculating speeds?

 

stock gearing, bike sees 130 mph every time I ride it. It has gone 150 half a dozen times for a few nano-seconds. I wana be nice to the old gal, not ring her neck out in the ever-glades :smile:

 

6th gens are stock 16/43

mine is now 15/43