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What ratio?

Posted: Tue Apr 26, 2011 11:12 pm
by soosh
Im am running SX200 box giving 4.8 but now got 100/90-10 tyres,what does this give now?
Ta

Re: What ratio?

Posted: Tue Apr 26, 2011 11:35 pm
by carlos fandango
soosh wrote:Im am running SX200 box giving 4.8 but now got 100/90-10 tyres,what does this give now?
Ta
The ratio stays the same, circumference of the tyre is larger, and that may give you 2 ish mph at top end :D

Re: What ratio?

Posted: Wed Apr 27, 2011 7:16 am
by coaster
carlos fandango wrote:
soosh wrote:Im am running SX200 box giving 4.8 but now got 100/90-10 tyres,what does this give now?
Ta
The ratio stays the same, circumference of the tyre is larger, and that may give you 2 ish mph at top end :D
I just checked with a Gearbox Visualiser Excel spreadsheet which I downloaded from somewhere (could have been form off here?) and for the same make tyre Swalbe Raceman, it says 100/90-10 = 136.4cm and 350-10 = 137.7. If you change makes then the figures fo all over the place :?
100/90-10 works out 3 mph slower at 6.5k rpm.

Re: What ratio?

Posted: Wed Apr 27, 2011 9:03 pm
by wack 63
I have Swalbe 3.50 on the front and 100/90 on the rear and they are both the same height stood together just that the 100/90 is 8mm wider measured with a vernier.When I set my digi speedo I measured the circumferance and got a different size to what is quoted,I used a cloth tape first on the tyres centre line then did the distance travelled along the ground sat on the scoot.

Re: What ratio?

Posted: Wed Apr 27, 2011 10:03 pm
by jonashford
The sizes for the swobbly tyres (for the digi speedos) are on the swobbly tyres web site linked to md developments web site, remember tho they do wear so the speedo will be a tint bit out as the tyre wears down. Minimal tho.

Re: What ratio?

Posted: Wed Apr 27, 2011 10:32 pm
by DaveTomo
http://www.tonycassidy.com/Gearbox_Visualiser.html heres the link for the visualiser

Re: What ratio?

Posted: Wed Apr 27, 2011 10:55 pm
by coaster
DaveTomo wrote:http://www.tonycassidy.com/Gearbox_Visualiser.html heres the link for the visualiser
That's the one 8-)