old - Fazer Owners Club - old
Bikes, Hints'n'Tips => FZS600 Fazer => Topic started by: the cueball on 24 March 2015, 04:29:42 pm
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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
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I'd need to slow down tomorrow and take a note for you B-)
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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...
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Mine sits around 61/2k at 70 with standard gearing.
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Mine sits around 61/2k at 70 with standard gearing.
Are you sure it is standard gearing? It seems to be -1 front sprocket.
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Mine sits around 61/2k at 70 with standard gearing.
Are you sure it is standard gearing? It seems to be -1 front sprocket.
mine is about the same
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mine is about the same
70 mph at 6200 rpm in 6th gear? That is certainly not the stock sprocket ratio...
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My 600 is as standard as they come & top gear at 70mph is a fraction over 6000rpm. Maybe 6100'ish.
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thanks all..
I had a feeling it was about 6 - 7k ish... give or take... :rollin
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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?
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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.
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so I could have a few speeding tickets coming in the post then?!?!
:'( :'(
:eek
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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.
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.
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6000 revs for 70mph.
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Speedo runs fast after 50mph so although the maths may be correct people will have slightly different figures to what the instruments tell them!
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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]
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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.
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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.
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got a phone?
attach it to the bike so you can see it and install a speedo app
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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.
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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.
most speedos read slightly wrong, id trust my phone gps over the speedo any day
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Of course GPS is way more precise.
What irritates my mind is the thing that many say their bike runs over 6000 rpm at 70 mph. Referring to the calculations above, 70 mph should be at around 5600 rpm. This is almost 10% difference. Tacho and speedometer should be more precise. In fact his speedo has to show less than the reality, which is not typical. Or the tacho has to show more than reality, which... yeah, we should test it with a proper rpm measuring device.
Might worth some experimenting on this topic in the future...
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Of course GPS is way more precise.
What irritates my mind is the thing that many say their bike runs over 6000 rpm at 70 mph. Referring to the calculations above, 70 mph should be at around 5600 rpm. This is almost 10% difference. Tacho and speedometer should be more precise. In fact his speedo has to show less than the reality, which is not typical. Or the tacho has to show more than reality, which... yeah, we should test it with a proper rpm measuring device.
Might worth some experimenting on this topic in the future...
I bet you're mates have fun winding you up ;)
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.
Basically I wasn't ;)
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I bet you're mates have fun winding you up ;)
Sorry, don't really know what does that mean. English is not my best...
A few pounds perhaps. ;) You can't put a guaranteed standard on how hard an engine has to work.
RPM, transmission, gear ratios and wheel speed are proportinal to each other. The only thing between them is the clutch. Don't know what else were you talking about.?
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A few pounds perhaps. ;) You can't put a guaranteed standard on how hard an engine has to work.
RPM, transmission, gear ratios and wheel speed are proportinal to each other. The only thing between them is the clutch. Don't know what else were you talking about.?
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engine won't need to work as hard going down hill as it would going up hill for the bike to reach 70mph
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Its odd that the speedo is not an MOT test item
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engine won't need to work as hard going down hill as it would going up hill for the bike to reach 70mph
RPM is the same uphill and downhill if the clutch is engaged. It has nothing to do with the "work".
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Ok I'm with ya now.
But I'm still over 6k at 70mph standard bike ;)
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Mine reads about 5,800 or 5,900 at 70mph
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Ok that got some very mathematical responses, when I say 61/2k rpm, I use this as a rough guide. I have a Speedo that occasionally goes weird, apparently I was doing 125mph around a roundabout I usually take at least than 30 a couple of weeks ago so when it was behaving itself I checked and displayed 70mph is just under 6500rpm = won't get nicked.
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Commuting to work I feel compelled to jump off and stand corrected. 70mph between 5800 and 6 rpm, 6500 is my normal riding area :o sorry Rhinoela
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thanks everyone, very interesting answers... :rollin
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I have a Speedo that occasionally goes weird, apparently I was doing 125mph around a roundabout I usually take at least than 30 a couple of weeks ago
Check the route of the speedo sensor wire in particular by the brake disc. Weird speedo readings are often caused by the edge of the disc wearing through the insulation and contacting the copper wire and sending confusing pulses to the speedo
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Popping down the road for a jolly jaunt shows that at an indicated 70mph, my tachograph is reading 5900rpm, in standard gearing in top gear.
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Yep I get 5800 at 70mph standard bike! There is also quite a variance depending on tyre condition n profile. A few extra mm in tread has a large impact on the circumference of the front wheel hence a difference in speed reading..... Also how much tread on rear tyre will also affect the drive ratios.
Hehe I await the flaming :)
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I have a Speedo that occasionally goes weird, apparently I was doing 125mph around a roundabout I usually take at least than 30 a couple of weeks ago
Check the route of the speedo sensor wire in particular by the brake disc. Weird speedo readings are often caused by the edge of the disc wearing through the insulation and contacting the copper wire and sending confusing pulses to the speedo
There is a nick in the the insulation by the disk, I just need to get around to getting it sorted but until then.......
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......wrap a bit of insulating tape round it to stop water getting in and leave for about 7 years.
It was good insulating tape its not even been replaced!
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My 600 is as standard as they come & top gear at 70mph is a fraction over 6000rpm. Maybe 6100'ish.
Correction :o :o :o: Just been out on the bike for the first time in ages & made a special point of double checking this figure. At 70mph on the speedo the tacho is reading, as close as I can tell, 5650 RPM.
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Standard gearing from my POV:
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I make mine to be 5850 rpm standard bike, dosent look quite like 5900