Top speed two-way test

[gavinfdavies]

I'm lucky enough to live near a flood plain with a 3 mile stretch of dual-carriage way (2 lanes each way) that's ruler straight and perfectly flat. Conveniently, the powers at be also put some wind turbines at each end which do a lovely job of letting you know the exact wind direction and rough speed.

Bike is engine-wise bone stock, 1996, 7,000 miles. The bike does have some suspension mods (Racetech emulators and springs up front, Hagon rear with remote preload adjustment) and is running Pirelli Diablo Scooter tyres in stock sizes. Position was full tuck, feet on correct pegs, and mirrors in usual position.

Results: 95mph (gauge) straight into the wind, 106mph (gauge) straight down the wind. Average 100.5mph, so I'm claiming that as a win!

Now all I need is a GPS unit to do proper testing.

[Singh2jz]

That's awesome!! hahaha!!

I would love to take my bike there for testing!!

[gavinfdavies]

Originally Posted by Singh2jz

That's awesome!! hahaha!!

I would love to take my bike there for testing!!

It's perfect for except, except for a random 50mph speed limit (usually 70). I mean, almost no junctions, remote area, next to a deserted steel-works, with a large separate cycle/footpath.

https://www.google.co.uk/maps/@51.57...7i13312!8i6656

It looks like that for the 1 mile until you reach a quiet set of lights for a galvanising works, and a roundabout half a mile after that.

The cyclists on the path must have been giving me filthy looks when I shot past one way, then the other, then again on the final trip home.

[JohnnyBravo]

Sounds like fun

[DannoXYZ]

If you get accurate tach-reading, you can also calculate speed going through gear-box, sprockets and tyre-radius.

[jkv45]

Originally Posted by gavinfdavies

I'm lucky enough to live near a flood plain with a 3 mile stretch of dual-carriage way (2 lanes each way) that's ruler straight and perfectly flat. Conveniently, the powers at be also put some wind turbines at each end which do a lovely job of letting you know the exact wind direction and rough speed.

Bike is engine-wise bone stock, 1996, 7,000 miles. The bike does have some suspension mods (Racetech emulators and springs up front, Hagon rear with remote preload adjustment) and is running Pirelli Diablo Scooter tyres in stock sizes. Position was full tuck, feet on correct pegs, and mirrors in usual position.

Results: 95mph (gauge) straight into the wind, 106mph (gauge) straight down the wind. Average 100.5mph, so I'm claiming that as a win!

Now all I need is a GPS unit to do proper testing.

Chances are you will find the speedo reads close to 10% high, so actual speeds might be in the 86-88 to 95-97 MPH range.

Different brands of the same size front tire will change speedo readings significantly due to differences in diameter.

GPS is the way to go if you really want to know. It is good to know your exact speed, otherwise you are cruising along thinking you are at the proper speed on the highway and wondering why everyone is going so !#$%! fast - when really you are going slow.

I have SpeedView app on my phone that works well.

[gavinfdavies]

Originally Posted by jkv45

Chances are you will find the speedo reads close to 10% high, so actual speeds might be in the 86-88 to 95-97 MPH range.

Different brands of the same size front tire will change speedo readings significantly due to differences in diameter.

GPS is the way to go if you really want to know. It is good to know your exact speed, otherwise you are cruising along thinking you are at the proper speed on the highway and wondering why everyone is going so !#$%! fast - when really you are going slow.

I have SpeedView app on my phone that works well.

I wouldn't be at all surprised. Don't have a smart phone, so will need to borrow either a sat nav or a smartphone with the relevant app. Once I've 'calibrated' my speedo I'll atleast know what to mentally adjust for.