This topic started in another thread but it was in a different forum. I bought my '05 VFR a year and a half ago and I have never been able to reach a top speed over 137 mph. This surprises me because my 98 and 2000 vfr's all would do 155 consistently. The bikes are fairly similar in weight and engine size. I do weight 30 lbs more, 215 versus 185 before, but I really wouldn't expect that to make an 18 mph difference in top speed. So I am throwing it out to the masses, what could be wrong with my bike?
The bike runs great. It is very smooth, starts right up. I have had no issues with the bike. I love it. I have a stock windscreen and I do have hardbags attached, but I have tried to top it out without the bags and it made a very small difference. I bought the bike with 4k miles and it now has 14.5k. So the engine is basically new. Thoughts?
I would like to say that this is not really a big deal, I very rarely top out a bike. But I am merely concerned it could indicate that there is a problem with the bike. I have always found this bike to be slightly slower than the 98 and 2000 that I owned.
What are you using to measure your speed? Even GPS units have small inaccuries and small differences in things like air temp and tire pressure are magnified when tring to achieve to speed. If it makes you feel any better mine (04) tops out right around 150 with a +2 on the rear sprocket.
With all due respect...isn't 137mph fast enough? I've ridden mine that fast once, and the thought of crashing at that speed scared the living hell out of me...
As for speed differences, does it have stock sprockets? are your measurements using the speedo? right tire size? and 30 lbs will make a difference.
Personally, I wouldn't worry about it. Ride the piss out of it and enjoy!
I know the thread he is referring to and it had a LOT of responses. Naturally, many of them were of the "that is wrong to ride that fast or even talk about riding that fast anywhere outside of the track" kind and the rest were people gladly chiming in with how fast they had gone. Of that second set, some of the speeds quoted were simply too high (crazy high) but the rest of them were believable (and they are higher than Pashnitrider's speed). Naturally, the speedo accuracy issue was talked about (10-15% at those speeds). Pashnitrider's point here is that HIS top speed IS quite a bit lower than the other believable speeds. And with the optimistic speedo error that all of our bikes have, his top speed SHOULD be higher than what he is seeing. So, unless HIS speedo is REALLY off (and is pessimistic which is the opposite of all bike speedos), his bike IS slower. I agree...riding past the speed limit is wrong, dangerous, etc. But, almost all of us have done ut, right? His question is valid. The mags are clear...his VFR is capable of more than approx 123mph (his indicated speed minus 10%)
So what could it be in his case?
Bad fuel, dirty injectors, dirty/clogged air filter, bad sensor causing fueling problems, misadjusted throttle cables, unknown sprockets, using wrong engine oil which allows clutch to slip under load, not tucking in... is that enough to start with?
Thank you for the responses and I was in 6th gear, so perhaps that is the problem. I was not maxing out 5th gear. As a disclaimer I would like to point out that this was all done legally on a track (cough cough) :rolleyes:
I thought this was rather funny at first, but hat is a pretty low top speed. The 6th gen pulls all the way thru fifth gear but seems to hit an aero wall in 6th gear above 120-130.
You will need to retrofit the 6th Gen with GEAR-DRIVEN CAMS to improve your terminal velocity. This is a widely known fact and explains why your Gen 5's were faster.
My bike is fairly new and I've hit 142 in 6th at about 8k on a flat higway. The engine was not even winding out yet. I was impressed at how fast it got there and I backed off of that speed right away. The bike is an 08 with no bags and totally stock. I weigh about 230 and I was not tucked in tight when I hit that speed. My gps matched it as well. I've only done this once and did not know the top speed was 137. :blink:
[image: View Post]indianagenius, on Dec 10 2008, 05:22 PM, said:
You will need to retrofit the 6th Gen with GEAR-DRIVEN CAMS to improve your terminal velocity. This is a widely known fact and explains why your Gen 5's were faster.
I don't know whether or not the 5th gen. bikes are faster than the 6th gen. ones, but they are quicker. Sport Rider magazine has the following quarter mile times/trap speeds on their web site:
5th gen.: 11.14 @ 122.18
6th gen.: 11.33 @ 118.5
If you go by what the magazines tell you, the 6th gen. VFR tops out around 150. If you're adamant about achieving this, there are several things you're gonna have to do:
1) Ditch the hardbags. They add weight and wind resistance.
2) Start your top end run from a standstill. Go through each of the gears at full throttle and upshift at or close to redline.
3) Stay tucked in the entire time.
4) I once read something on how one magazine did their testing. To make a long story short, virtually all of their testers weighed in around 150 lbs.
weight will make a negligible difference in top speed. unless there is more bulk going with that mass, increasing your frontal area, or poorly placed mass increasing drag.
when you try topping, hit redline in 4th gear and up. and you need alot of space. my vfr tends to accelerate very slowly near top speed. although it will pull redline in top gear(down one tooth up front). although you have topped out previous vfr's without apparent issues.
is your gearing stock? from what i am understanding, it runs perfectly otherwise. something is wrong if your only pulling 130something indicated.
and was there any wind when you were trying to top out? if you have a strong head wind it could make a very large difference.
If you really want to know if something is wrong with your bike I would suggest doing some objective testing (dyno runs) to confirm power output instead of just guessing. Sounds like something is not quite right.
I was tailing a couple of friends who were far quicker than I to pass on the double-yellow and found myself about 8 cars behind them after a while. We came across a stretch of long straight two-lane and I hit 3rd and tore out from behind them and made my pass. As I passed, I rode out each gear until I shifted up into 6th and by that time, I was pulling back into my lane having cut the throttle. I glanced down and saw my speedo drop past 135 as I let it wind down.
The GPS unit read a top speed of 144.4. And that was immediately after shifting into 6th. Still had plenty to go. ;)
I don't do it alot but often enough to know that my stock '03 routinely does 265km/h indicated speed with no bags mounted. I have a good long stretch of road that is as level as a public road can be. Since I've done this everal times (trying to keep up with the R1's of the world) I've also done this with my gps mounted. The gps corrected speed is 255 km/h. At that speed the bike just runs out of go, it's turning around 10,000 rpm but it just won't accelerate anymore. So if your bike is stuck at 137 I'd have someone take a look at it. For my American friends 255 km/h is exactly 158.45 mph.
[image: View Post]pashnitrider, on Dec 10 2008, 04:52 PM, said:
Thank you for the responses and I was in 6th gear, so perhaps that is the problem. I was not maxing out 5th gear. As a disclaimer I would like to point out that this was all done legally on a track (cough cough) :rolleyes:
Run 5th up though 125mph hard and youll bust through quickly , but depending on headwind, just trying to run 6th from 100 to 135 + would take along time.
at 15 000 mile your airfilter could be in fact very contaminated , I've seen them 80% blocked at 15 and others not so bad, you have to look through in bright light. adding 1 or 2 teeth on the rear you'll probably gain top speed, just because the bike is overgeared in 6th.
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