what roll out is everyone using

[CHRIS_MORRISON]

what roll out is every one using
I'm using
39.95 mm

[Grinder]

Anywhere between 40 to 45.  Usually around 43...

im always between 39 and 41

[gotnitro]

86 to 90 :lol:

[jarrodH]

i think mine was about 33, or 34 on saturday, my lap times were about 4 or 5 in the A

[jarrodH]

oops.   43, 44

[SgRddY]

What is the formular to calculate the roll out?  Yes, I have to learn it one way or another.  Have been trying to ignore this but can't anymore.

[Grinder]

(Tire diameter * pi) / (Spur gear /  pinon gear)

(50mm * 3.14) / (96/26) ~ 42.5 for my mains roll out this week....

[Blake]

For the less algebra inclined, this formula is equivalent to Kurk's and it's easier to use with a basic calculator:

(Tire Diameter * Pi * Pinion Gear) / Spur Gear

(50mm * 3.14 * 23) / 88 ~ 41.0 for my main rollout last race day


It's as simple as multiplying the first three numbers together, and then dividing by the spur gear.  That way you don't have to remember any intermediate steps.


Blake

[Tom]

I'd reccommend http://www.gearchart.com for easy refrence, however the website doesn't seem to work any more.  It would be easy enough to rig up a spreadsheet to create your own gear charts though.  That way no calculators are needed at the track, and you don't need a calculator to keep the same gearing when you change tires.

[DekelzMan]

Tom,

Gearchart.com is working just fine for me. Maybe your 600 year old pentium 1khz is finally giving up

Or have you switched over to that 2" square Linux beast you were talking about ?

Mick

[Tom]

I had tried it from both home and work and was unable to resolve the name.  Could you possibly be using a cached copy?

[DekelzMan]

Nope, she's live here and now on multiple browsers.... I just created the rollout for an Alex Barrcuda R2 which I have never heard of and certainly never created a chart for and all is working properly...

[Tom]

Works for me now too.  Perhaps the site was just down for a few hours while I tried and has subsequently started working again.

Like I said, this is easier than using a calculator, but it is important to understand what the charts say, which is where understanding the above algebra comes in.

For those that need some help, roll-out is the distance your car moves for every revolution of your motor.

[wew]

40