Wow - unbelievable motorcycle video.

[GasX]

<click>

If you think it is real, the guy goes to 140mph on just the back wheel and then all the way to 220mph. Considering how fast the world seems to be moving, I have to think the speedo is messed up...

 

I can't really see clearly but most likely that is Kilometers per hour.

 

[jteef]

i thought it was kph too, but the inside numbers are higher, so I am thinking that it is mph.

jt

 

[radioouman]

I thought it was kilometers too, but you can see the smaller numbers on the inside of the speedometer that are higher than the bigger numbers. So it really does look like mph!

In that case, some people are just asking to die!

 

[GasX]

Originally posted by: Roger
I can't really see clearly but most likely that is Kilometers per hour.

You can't see explicitly, but the smaller set of numbers on the inside of the dial is on a higher scale and is presumably KPH

 

[jcovercash]

:Q

 

I don't believe that he is traveling that fast, your observation about how fast he appears to be moving convinces me that he is not.

 

[Viper GTS]

Motorcycle speedos are notoriously inaccurate at high speeds...

Or so I heard when things like this were posted before.


Viper GTS

 

[jcovercash]

Originally posted by: Roger
I don't believe that he is traveling that fast, your observation about how fast he appears to be moving convinces me that he is not.

He may not be going that speed, but he is still flying and this video reminds me of how completlystupid some people are when it comes to life lol

 

[GRIFFIN1]

He probably just changed the rear sprocket without getting new gears for the speedometer.

 

[JOSEPHLB]

in actuality.. probably about 200mph..
like Viper GTS mentioned.... motorcycle speedometers are a little bit off...

according to Honda, my 2002 F4i is going 28mph (30mph actual speedo reading) and 57mph (60mph actual speedo reading)

when approaching speeds of 125MPH+ and then some.. the actual error can be as high as 10%

this bike in this video is doing a wheelie at 140mph..
I've saw videos of bikes doing straight up stand up wheelies in 1st, 2nd, 3rd and 4th gears... with huge riders and huge bikes.. You dont get this from stock form.... most of the modifications involve changing the front or rear sprocket.. Thus, resulting in even more speedometer error

 

[boi]

I didn't watch that video but is that the Hayabusa that goes past the speedometer?

 

[Fausto]

Originally posted by: GRIFFIN1
He probably just changed the rear sprocket without getting new gears for the speedometer.

I'm inclined to agree.

Where's Hayabusarider? He could clue us in since he's got the same bike as to whether this is accurate or not. I timed the accelleration from 50 to 180 indicated at about 10 seconds; I know the 'Bus is fast and all, but that speedo needle moves awfully quickly upward from when he lands the wheelie.

 

[Bulk Beef]

Speedos are driven off the wheels, so gearing changes don't matter. If you change the diameter of the wheel that the speedo is driven off of (usually the front), that would change the reading.

And yes, m/c speedos are very inaccurate at speed.

 

[radioouman]

Originally posted by: Fausto1

Originally posted by: GRIFFIN1
He probably just changed the rear sprocket without getting new gears for the speedometer.

I'm inclined to agree.

Where's Hayabusarider? He could clue us in since he's got the same bike as to whether this is accurate or not. I timed the accelleration from 50 to 180 indicated at about 10 seconds; I know the 'Bus is fast and all, but that speedo needle moves awfully quickly upward from when he lands the wheelie.

I agree.... that would be some serious acceleration.

 

[Zenmervolt]

#1) Acceleration is too linear, it doesn't taper-off at all.

#2) Motorcycle speedometers are driven off the front wheel, if the front wheel is in the air, there is no speedo reading.

ZV

EDIT: At least, every cycle I've seen has had the speedo driven off the front wheel.

 

[308nato]

Thanks. I was waiting.


There are a few exceptions, but this is 99.9% correct for rice.

 

[Bulk Beef]

Looks like the Hayabusa might have the speedo drive on the transmission output shaft, so a gearing change would change the reading.

 

[MattCo]

Theoretically, couldn't some judge how fast the rider was going by using the distance between the lane divider stripes? Assuming that there is a standard lengh between highway dividers and that the video hasn't been speeded up, shouldn't it be simple math? I am too lazy to look up highway painting standards but someone on ATOT always knows usless trivia like this.

-MC

 

[308nato]

Originally posted by: MattCo
Theoretically, couldn't some judge how fast the rider was going by using the distance between the lane divider stripes? Assuming that there is a standard lengh between highway dividers and that the video hasn't been speeded up, shouldn't it be simple math? I am too lazy to look up highway painting standards but someone on ATOT always knows usless trivia like this.

-MC

Those stripes are put down by members of the Local Operating Engineers Union or a government employee.

Think about it.

 

[JOSEPHLB]

um... gear changes do matter.. and do change speeds and acceleration..
How do you think a 10 speed bicycle works..

if a biker modifies the front sprocket.. lets say.. dropping from a stock 16T to a 15T, .. its going to throw the speedo off considerably as well... Acceleration will improve... but.. the need to shift into higher gear becomes quicker..

go to some sportbike forums and look up changing gear ratios and sprockets.. It DOES matter..

 

[Damage]

Hello!

New Suzukis all run the speedo drive off the tranny.. NOT the front wheel Chaning greaing drastically screws with the speedo.. That's why black robotics made the Yellow box add on.. so you could fix it.

 

[JOSEPHLB]

a link for an Excel worksheet that calculates speeds, depending on gear ratios, front sprocket size, rear sprocket size.. tire sizes.. etc..


Motorcycle Gearing

Just plug in different gearing, and get an ideal of the changes..

 

[Zenmervolt]

Originally posted by: JOSEPHLB
um... gear changes do matter.. and do change speeds and acceleration..
How do you think a 10 speed bicycle works..

if a biker modifies the front sprocket.. lets say.. dropping from a stock 16T to a 15T, .. its going to throw the speedo off considerably as well... Acceleration will improve... but.. the need to shift into higher gear becomes quicker..

go to some sportbike forums and look up changing gear ratios and sprockets.. It DOES matter..

Uh, if the speedo is run off the front wheel (as it is in every bike I've ever seen, though I'm sure it's not universal) then as long as the diameter of the front wheel is unchanged, the speedometer's reading will remain accurate (or as accurate as it was originally). This is what people have been saying.

ZV

 

[308nato]

Originally posted by: JOSEPHLB
um... gear changes do matter.. and do change speeds and acceleration..
How do you think a 10 speed bicycle works..

if a biker modifies the front sprocket.. lets say.. dropping from a stock 16T to a 15T, .. its going to throw the speedo off considerably as well... Acceleration will improve... but.. the need to shift into higher gear becomes quicker..

go to some sportbike forums and look up changing gear ratios and sprockets.. It DOES matter..

The point was it doesn't matter if the sending unit is on the front wheel (or as in older Brit bikes and HD's, the rear wheel) it doesn't matter in the least what you do with the cogs. Those would only change if you swapped rim (and/or) tire sizes.

If the unit is located in the cases somewhere, yes, it most likely would need recalibrated (if the gear was even available).