Gearing for 200mph

[Kwee]

correct, one of the benefits of traction control

we have front and rear wheel speed sensors, not sure which one the bike uses for the speedometer, probably the front like champ said

either way changing gearing will not affect the accuracy of the speedometer

And it's very accurate, 2 km/h at 50 km/h(48 km/h) 3,5 at 90 km/h(86,5 km/h). It's exactly 4% and it's required by regulations autorities. 299 km/h display is 287,5 which far close compared to others speedometer.(On my old VFR it was 5%)

[kingroslolo]

42 in rear should be enough to do 200 mph but is the speedometer going to show 200mh? Look like in you tube video in km/h it show everyone max 299 kms (186< mph) per legislation? Note: in Central stand my speedo work

[Switch18]

42 in rear should be enough to do 200 mph but is the speedometer going to show 200mh? Look like in you tube video in km/h it show everyone max 299 kms (186< mph) per legislation? Note: in Central stand my speedo work

Do you think so....that would be good if you don't have to change the front cog as it looks a complicated affair. It's a measured mile with independent timing equipment so doesn't matter what my speedo says.

[kingroslolo]

42 is going to be harder to run at the max rpm in a mile measured speed be sure to max the 5 gear... Need to reach about 12500 in 6th, Good luck!

[jjscsix]

42 in rear should be enough to do 200 mph but is the speedometer going to show 200mh? Look like in you tube video in km/h it show everyone max 299 kms (186< mph) per legislation? Note: in Central stand my speedo work

Unless something has changed, there is no legislation. It is a “gentleman’s agreement”.

[FastNinja]

Hi guys,

I'm mechanical and i worked to kawasaki dealer. I'm a LSR racer and i breaked 200 mph at stand mile event. I'm 3 times champion on 1/2 mile event too. I have a lot experience on top speed event.

I write you for share my experience with real speed and gearing commander and sprockets.

First, never thrust a speedometer. GPS is very precise for to know the real speed you go. But, you must reach the max speed for 2-3 sec, because the GPS are rate to 1 hertz. I use Vbox Sport. They are rate to 20 hertz and it's for this reason, his very acurate.

Second, Gearing commander is a great tool. But, the software does not take into account of several factors that affect the real speed at high speed. For to get the real speed when you use the gearing commander. If your wheelbase is stock, just remove -3.2% at your rear wheeI circonferance data. Ex 190-55-17 = 79.26 in circonferance 79.26 - 3.2% = 76.72 in circonferance wheel. With the 3.2% factor correction, you will really near the real speed you will reach at high speed.

Third, 99% of the OEM RPM tach are not accurate too. Ex : when the OEM H2 tach indicate 13000 rpm, your real RPM is 12500 rmp. The H2 have 500 rpm error. I don't know for the H2 SX and SE ? It's important to know the precision on the tach of your bike. Because, it's have a big effect when you entrer the max rpm on the gearing commander. In general, the error on japenese bikes is between 200 and 600 rpm. The BMW S 10000rr tach is precise to 100%.

With this information, the gearingcommander you get the real speed with many combination of sprockets.

When you calcul the max speed vs combo sprocket.You always need some fews more mph than the speed you want reach.

The H2 SX and SE have short gearing. The max speed you can reach with the stock sprockets and stock rpm red line is ±181 mph. For the H2 SX and SE can reach 200 mph, you need 19 (+1F) and 42 (-2R) sprockets, at 12 250 real rpm.

Check the video link. It's a guy did max speed on H2 SX. Check the speedometer speed and real speed on GPS

I hope that informations help you for to find the real speed, you can reach on gearing commander.

[UFO]

Second, Gearing commander is a great tool. But, the software does not take into account of several factors that affect the real speed at high speed. For to get the real speed when you use the gearingcommander. If your wheelbase is stock, just remove -3.2% at your rear wheeIcirconferance data. Ex 190-55-17 = 79.26 in circonferance 79.26 - 3.2% = 76.72 in circonferance wheel. With the 3.2% factor correction, you will really near the real speed you will reach at high speed.

The spreadsheet on this website allows you to enter a measured wheel circumference (easy to do) to get better calculations. The default is calculated based on tire size and profile. Tires from the factory will probably not have the exact calculated circumference, and tires wear over time. So if you have a worn tire your circumference will be significantly different.

Blue cell is where you enter measure circ. By default it is set to be equal to the calculated value to begin.

For example, if you rolling rear circumference is reduced by merely 0.1 feet (1.2 inches) because your tire diameter is smaller than theoretical (for whatever reason) top speed drops by 3-4 mph.

[FastNinja]

Yes, you must measuring your circonference rear wheel. Each brand of tires have don't the same circonference for the same size tire.

Ex Dunlop Q3 190/50/17 don't have 1953.5mm the real circonference is 1980mm (brand new) and some other brand of tire have less than 1953mm. At the real circunferance you remove -3.2% for the bike have stock wheelbase. 1984mm - 3.2 % = 1920mm.

After you mesurment your cicronference rear wheel and remove 3.2%. It's this number you entrer in the gearingcommander for to do your calculation of sprockets vs speed.

[dan_h2sx]

Maybe changing the gearing is the easier way to go real (GPS proven) 187mph/301kph. I was thinking on getting a tune to achieve that speed but a small gearing change seems more reasonable :P

[Switch18]

So theoretically speaking a 19f + 40r would enable the bike to achieve 200mph as long as it’s got enough power.

If you ran a 19front sprocket would a 44 rear mimic current standard gearing.