Gearing Change (speedo)

[iMark]

Going to be changing my sprockets -1/+2 for a bit more poke and less top speed (Might make me behave a bit more on the speed aspect but not the wheelie aspect )

Will it throw my speedo/odometer way off or only marginally apart from top end?
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K8 GSXR 1000
"G" : you got him to have a look at a forum which seems to have established a picture of an erect penis in a cat's mouth as it's mascot and thought he might consider it ok?

[blade023]

I did just that on 2 bikes, and while it's a tad better the speedo over reads by a significant factor. Seems to increase at higher speeds. It was reading +10 +/- 2, at around the 40 mark. I tested it with a couple of sat nav systems though, and I can't vouch for their accuracy. Since going back to the stock front size, while keeping +2 on the back it's lessened, but at 30 it reads about 26.
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Current: VFR800 2008 13.7k and rising rapidly!
Sorn: 2003 FZS1000 30k(ish) looking to sell.

[Wull]

It'll defo be out,by as much as 10-12% I'd say and it depends how much its out by just now.
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"Scooters are for men who want to ride motorcycles but prefer to feel the wind on their vaginas"

[iMark]

10-12% won't bother me that much

Will get the GPS on my phone to check exactly what speed is 30-60-70 anyway to make sure
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K8 GSXR 1000
"G" : you got him to have a look at a forum which seems to have established a picture of an erect penis in a cat's mouth as it's mascot and thought he might consider it ok?

[iooi]

helpful site

You might even find it makes the speedo read correctly
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Just because my bike was A DIVVY, does not mean i am......

[iMark]

Yeah I've used the site before, I've had 160 indicated but I doubt that's spot on

considering the bike is 14 years old and done 40k now..
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K8 GSXR 1000
"G" : you got him to have a look at a forum which seems to have established a picture of an erect penis in a cat's mouth as it's mascot and thought he might consider it ok?

[Wull]

When I had my zx9r c1 the speedo was maybe out by 5% with standard gearing but tbh I don't think I ever checked it!then I fitted a -1 front sprocket and that put it out by about 10% iirc.

You'll notice a big difference in your gears and revs,you'll be maxing out in 6th all day long and the speedo will be more than likely topping out as well due to the error.

If you're getting 180 chances are it'll be roughly 160 odd or there about.

Just wheelie everywhere anywhere that's all that matters
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"Scooters are for men who want to ride motorcycles but prefer to feel the wind on their vaginas"

[iMark]

https://i.imgur.com/9GHTCIR.png

I done a thing...


Now for the waiting....

Get em changed over ready for the weeekend! and turn my phone off so I can't be called into work


Oh also, I'm aware it says ZX7RR not ZX6R .. same sprocket though, just stock is 40 on the ZX6R and 42 on the ZX7RR so advertised as ZX7RR
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K8 GSXR 1000
"G" : you got him to have a look at a forum which seems to have established a picture of an erect penis in a cat's mouth as it's mascot and thought he might consider it ok?

[iMark]

Math time... Gearing Commander says 161 top speed for current gearing

and 143.1 with -1/+2 so..

161/100 = 16.1
143.1/16.1 = 8.88819~~~~~~something

So my speedo will over read by 8.9%.

Basically add 10% on, so if I'm doing 33 I'll be doing 30.. 44 and 40 etc.. right... Seems easy enough!

Obviously depends how accurate my speedo was originally is...
but if it over reads by 10% naturally and I'm doing 30 right now and I'm only doing 27mph then a further 10% means I'll only be doing 23 mph?

Guess I'll need to duct tape my phone to my yoke and get a GPS speedo to double/triple check true speed a various speeds..
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K8 GSXR 1000
"G" : you got him to have a look at a forum which seems to have established a picture of an erect penis in a cat's mouth as it's mascot and thought he might consider it ok?