Sprockets and speedo

[seth]

The red and black bike had it's 1st new chain and sprocket kit yesterday .
So I thought when I got it with 6500 miles on it the guy had fitted a good chain as it looked better but on word on sprockets .
The bikes always been quick away and pulled very strongly so imagine my suprise that when change the front I found it was a 17 tooth standard Suzuki one not 18 tooth.
It explains why it pulled so well .
Using my sat nav(phone app)
I checked the speeds
On the 17 tooth front sprocket
The Speedo reads about 10mph higher than the actual speed
Now with the standard 18 tooth one fitted it reads around 5 mph higher than actual speed .
Thinking a 19 tooth sprocket would read the correct speed .

[Hooli]

Shouldn't they read over with standard gearing? Is it the normal sprocket on the rear?

[gsxbarmy]

Most GSX1400 speedo's read over by about 9% so if yours is running under @seth, then you must have one of the better ones. Either that or the clocks were modded and the needle has been put back on a couple of cogs round the spindle perhaps

[KiwiCol]

Something isn't quite right there Seth???  With a 17 front, the engine revs higher for a given speed, the speedo pickup is on the sprocket nut, so the faster that nut goes around, the faster the speedo thinks the bike is going. With the 18 front, it's turning slower for a given speed yet the speedo thinks it's going faster?  (-10mph on 17T & -5mph on 18T??)  Should be the other way around I'd say.

Only way it could work like that is if the speedo pickup was off somewhere else or it's got a speedo corrector that isn't set correctly, I'd say.

[Globalrider]

It is an Oz sprocket!!!

Stan

[seth]

It is lazier on the pick up but is showing the speeds I put up 76mph on the clock is 70 mph where it was 80 mph on the clock being 70mph before the change .
Both rear sprockets are 41 teeth .

[KiwiCol]

Ahhh, well then, it's reading over not under.  You originally said the speedo reads low by 10 mph then low by 5mph after 18t sprocket.  It's all normal for our setup. 

[seth]

Sorry col.
its the way I put it that wasn't the best I had been drinking at the time.

Posts now edited hopefully making more sense.

[KiwiCol]

Yeah yours does, but Barmys & mine, now don't.  Never mind, it'll be the heat & lack of water up there.  Best get a cool Rum & diet coke down ya.

[Notty]

I don't have all my original teeth and i do go a lot slower if that helps 

[ARH]

I don't have all my original teeth and i do go a lot slower if that helps 

 

[froudy]

I've partaken of a few too after a 12 hour night shift and major lack of sleep...20 hours and counting
Best of luck finding a 19t front sprocket @seth 

[seth]

@froudy

http://gsx1400owners.org/forum/index.php?topic=550.15
Topic on them here so they were available and fitted in the past .
Looks very close to the cluth pushrod but enough clearance.