70mph in top gear???

[the cueball]

since my speedo is still goosed, can someone please tell me what revs the bike sits at in 6th gear at 70mph please....


I've got the others figured out (30/40/50/60) so its the only one I don't know!


many thanks!!


:o

[sinto607276]

I'd need to slow down tomorrow and take a note for you B-)

[rhinoeli]

6th gear with original sprocket ratio is very easy in km/h

50 km/h -> 2500 rpm
100 km/h -> 5000 rpm

70 mph = 112 km/h -> 5600 rpm

Hey, if you figured out 30 mph, you can do math to get revs for 70 mph...

[greenman]

Mine sits around 61/2k at 70 with standard gearing.

[rhinoeli]

Mine sits around 61/2k at 70 with standard gearing.

Are you sure it is standard gearing? It seems to be -1 front sprocket.

[midden]

[quote author=greenman link=topic=16362.msg188340#msg188340 date=1427218557]
Mine sits around 61/2k at 70 with standard gearing.

Are you sure it is standard gearing? It seems to be -1 front sprocket.
[/quote]
mine is about the same

[rhinoeli]

mine is about the same

70 mph at 6200 rpm in 6th gear? That is certainly not the stock sprocket ratio...

[YamFazFan]

My 600 is as standard as they come & top gear at 70mph is a fraction over 6000rpm. Maybe 6100'ish.

[the cueball]

thanks all..


I had a feeling it was about 6 - 7k ish... give or take...  :rollin

[rhinoeli]

What the heck... Ok, seems everyones FZS600 except mine runs over 6000rpm at 70mph in 6th gear.

Mine is a metric instrument model with standard (15/48) sprockets.

It shows:
100 km/h -> 5000 rpm
112 km/h (70 mph) -> 5600 rpm

gearingcommander.com confirms these numbers.

What am I missing?

[Millietant]

What the heck... Ok, seems everyones FZS600 except mine runs over 6000rpm at 70mph in 6th gear.

Mine is a metric instrument model with standard (15/48) sprockets.

It shows:
100 km/h -> 5000 rpm
112 km/h (70 mph) -> 5600 rpm

gearingcommander.com confirms these numbers.

What am I missing?

Don't think you're missing much - our is also on standard sprockets and gearing and 70 comes up under 6,000 as well.

Don't know what s going on but it looks like we have sprocket changing ghost hanging around.

[the cueball]

so I could have a few speeding tickets coming in the post then?!?!


:'( :'(


:eek

[Frosties]

[quote author=rhinoeli link=topic=16362.msg188375#msg188375 date=1427230178]
What the heck... Ok, seems everyones FZS600 except mine runs over 6000rpm at 70mph in 6th gear.

Mine is a metric instrument model with standard (15/48) sprockets.

It shows:
100 km/h -> 5000 rpm
112 km/h (70 mph) -> 5600 rpm

gearingcommander.com confirms these numbers.

What am I missing?

Don't think you're missing much - our is also on standard sprockets and gearing and 70 comes up under 6,000 as well.

Don't know what s going on but it looks like we have sprocket changing ghost hanging around.
[/quote]


Mine sits just under the 6k at a SatNav indicated 70mph. My speedo went last year so had to use a Tom Tom for speed for a couple of weeks.

[HarryHornby]

6000 revs for 70mph.

[Punkstig]

Speedo runs fast after 50mph so although the maths may be correct people will have slightly different figures to what the instruments tell them!

[midden]

What am I missing?

A few pounds perhaps.  [size=78%]  You can't put a guaranteed standard on how hard an engine has to work. [/size]

[rhinoeli]

A few pounds perhaps.  [size=78%]  You can't put a guaranteed standard on how hard an engine has to work. [/size]

Basically you are talking about the cluth slipping which may count at hard accelerations or much higher speeds and rpms. Don't think it is the case here.

[rhinoeli]

Ok folks, let me do some maths to clear things up. I am using values from the specifications found in the official service manual.

Primary reduction ratio is 82/48 (1.708).
Gear ratio in 6th gear is 29/27 (1.074).
Secondary reduction ratio with standard sprockets is 48/15 (3.200).
Diameter of the rear wheel is around 600 mm (depending on tire type, pressure, rotation speed etc), so circumference at 100 km/h must be around 1900 mm.

Let's assume 5000 rpm.
5000 / 1.708 / 1.074 / 3.2 = 852 rpm = 51120 wheel rotations per hour
51120 rotations per hour * 1900 mm = 97 km/h

So we can roughly calculate 6th gear speed/rpm ratios with the following:
50 rpm -> 1 km/h
80 rpm -> 1 mph (5600 rpm -> 70 mph)

My Fazer's instruments confirm these numbers. Also gearingcommander.com gives almost the same results.

[Paulfzs]

got a phone?


attach it to the bike so you can see it and install a speedo app

[rhinoeli]

got a phone? attach it to the bike so you can see it and install a speedo app

Done that. My speedo cheats around 3-4% up.