srx gearing

A

AtlasFBG2

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May 2, 2003
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Age
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Location
Fremont,Ohio
Im looking to change the gearing in my 00 srx.We ride mostly UP and some lower of Michigan trails.Usually race down county roads or fields.Im looking to gear it for top speed around 90-100.Thats when everyone backs off the gas.Thinking of going 23/40 or should i go lower?Stock srx is geared for 120 if im right?Anyone know how to figure out what gearing equals to speed?Thanks guys.
 
Think i figured it out.With the clutches at 1:1 shift 20/40 would give me 91 mph, 21/40 would give me 95 mph, 22/40 would give me 100 mph.Stock 23/38 would be 110 mph.Does that sound right?
 
Arctic gearing though....:)

This is for A-C but it would be of some guide: :)

18/39 8300Rpm 148,5km/t
19/39 8300Rpm 156,7km/t
20/39 8300Rpm 165,0km/t
23/39 8300Rpm 189,7km/t
18/40 8300Rpm 144,8km/t
19/40 8300Rpm 152,8km/t
20/40 8300Rpm 160,9km/t
23/40 8300Rpm 185,0km/t
24/40 8300Rpm 193,0km/t
18/42 8300Rpm 137,9km/t
19/42 8300Rpm 145,5km/t
20/42 8300Rpm 153,2km/t
23/42 8300Rpm 176,2km/t
18/44 8300Rpm 131,6km/t
19/44 8300Rpm 138,9km/t
 
Here is the formula for a yamaha with 9tooth drivers (stock).
RPM/Gear Ratio X 22.68/12 X 60/5280 = MPH at 1:1 shift out.
So here it is for your 23-40 ratio at 8400 rpm.
8400/1.739x22.68/12x60/5280= 103.7 mph
Looks like that will work just fine for ya. ===SRXSRULE===
 
Rules great gearing info. But I can't understand the math. Can you help me define what 22.68, 12, 60 and 5280 represents in your example. The only thing part I understand is the RPM/Gear Ratio. I have 8 tooth drivers and an 1.25 track.
 
Mac.... Try and figure it out :) 5280 is the # of feet in a mile... the formula isnt that tough. Whats your gearing combo and I will figure out your mph with the 8T drivers. ===SRXSRULE===
 
Rules Viper 23/38, 8 tooth drivers, 1.250 track, cpr pipes@9300rpm.
I'm still trying to figure out the rest of the formula, come on rules make with the info. Mac
 
The formula i used to figure it out came from Olav Aaen's clutch tuning handbook.The book is worth buying.Lots of great info on understanding clutches.Its a little diferant formula from what Srxrules used but the results are very close.Only 1 mph diferance.Heres what the handbook says.

engine speed times sprocket pitch diameter divided by shift ratio times gearing times 336 equals mph.

engine speed= rpm
sprocket pitch diameter=sprocket diameter+track thickness
gearing=driven sprockets divided driving sprocket
shift ratio= driven clutch belt radius divided by driving clutch belt radius.Usually 3:1 in low and .75:1 in high.1:1 shift ratio gives you beter efficiency than overdrive.

So you would have to measure the diameter of your 8 tooth drivers and the thickness of your track.For an example if your 8 tooth drivers measure 6 inches and track is 3/8 thick you would take.
9300x6.125=56962 then take 1x1.65x336=554 then take 56962/554=102 mph
 
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