Topic: tires

[jamie_guy3]

i got 16 inch if i go whit 13inch is this change my tran.ratio is 3to1 thanks

[mightymowe]

the circumfrence of the tire changes quite a bit from a 16" to a 13" tire and it would probably require a change in the gear ratio,unless you wanted less top speed and more acceleration.

[jamie_guy3]

i got 7inch motor 5 tranny 15 sproket in front 45 axle i whant to go 50 to 60 in 200 feet lenth is this good

[mightymowe]

there is a whole lot more that comes into play, like how much power do you have,you could gear the tractor to go that speed and not have the power to pull that gear and give acceptable acceleration or if your tractor is real heavy or you are real heavy you may need more power, and you may not need to even go that fast to be the fastest one out there. we have beaten many guys with more power than us by simply having our tractor handle better and we could get on the throttle sooner or be on the throttle longer into the corner. the gear ratio is also dependant on what rpm you want to run. so I say just put some gear on there and go out and get some seat time and see what you need from there

[Squidd]

We went thru the calcs in another thread...and with th 7/5 and 15/45 and 16" tires...you should be in the "Ballpark" with your gearing...

There is a further calc to tell what your mowchine is "Capable" of in speed...Meaning, XXXXrpm * X.XX gearing with XX" tire circumfrence "should" go XX mph...

BUT..as mightymowe says...there is more to it that that...

Is your motor capable of turning XXXX rpm..? Does your motor produce enough "torque" to spin it up to XXXX rpm in 200'...? Does your mowchine "handle" well enough that you can get into it and pull XXXX rpm...? Or is it bouncing and fighting thru the exit and entry of the corner and you really can only "pull" for 150'...and not make top speed...?

Gearing for XX mph "on paper" is a fun exersize...but does not always translate to "real life" speed until the other factors are worked out...

Again, geared as above, you are in the "ballpark" of reaching those speeds...Now it's up to you..your motor..and your mowchine to see "IF" you can handle them and hit them out on the track...run the bases...

And fine tune from there...