Advise for me about gear ratio

[Han sungsoon]

I contest first I how must do gear ratio(final ratio) well know .
Advise in gear ratio choice.
thanks for reading

Han http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Han sungsoon]

I contest first I how must do gear ratio(final ratio) well know .
Advise in gear ratio choice.
thanks for reading

Han http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Disco]

What size tyres (10", 13" etc) are you using? And what sort of engine? You'll need to find out the primary, first, second etc reduction ratios to determine the final drive ratio. You'll also need to determine what speed you want to be doing in which gear.
Get me that information and I'll run the calculations for you.

Cheers
Steve

[Daves]

Does changing the front sprocket change the primary reduction?

http://www.letu.edu/formula

My Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[Marc Jaxa-Rozen]

As far as I know the primary reduction involves internal transmission gearing...your front/rear sprockets would change the secondary reduction.

For our CBR600 this works out as a stock primary reduction of 1.863:1 together with a 3:1 secondary drive (sprocket), and would yield a 5.59:1 final ratio. Which, BTW, is probably way too tall.

Marc
ENAF1

[Daves]

5.59:1 is fairly tall, but not quite as tall as the bike. What year CBR600 has a 1.863:1 primary reduction? Our F4i has a 1.822:1 primary.

http://www.letu.edu/formula

Formula Photos & Links (http://what3542.5u.com/dave/fsae/formula_photos.html)

[Kevin Hall]

I believe thats an F2 or F3 their skipper (92-98)

Kevin Hall
University of Saskatchewan
'03-'04 Team Director

[Marc Jaxa-Rozen]

Yup, we're running an F2. That gearing means a ~195 kph top speed...it's nice to boast about in public presentations, but it probably makes most of 3rd and 4th gear useless on the Detroit course.

Marc
ENAF1

[Ben Beacock]

People aren't very impressed when we tell them our top speed is 140kph and it seems like its always the first question asked. There is then a quick reply about gearing for acceleration, our 0-60 speed, and a theoretical top speed if the gearing was changed.

Our primary is 1.926 (gsxr600)
final of 3.6 (ring and pinion)
for a total of 6.9336
13" wheels

Ben Beacock
Co-Manager
2004 Gryphon Racing - University of Guelph (http://www.soe.uoguelph.ca/uogracing)

[gug]

so what do you say your theoretical top speed is with gearing changed? do you take into account drag, friction, or is it a bit of a guess just for the sponsors?

- the problem with the world is stupidity. i'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety lables off of everything and let the problem solve itself?

[karter]

most people that asks how fast a racing car can go don't have a clue what racing is about, so, make up an impresive number, wow 'em and ask e'm for money!

[Ben Beacock]

if the 6th gear was dropped to an overall ratio of 4.5, then we'd still have 175Nm of torque, or 350N of driving force at the wheels at 200kph. We haven't touched aero, so don't even know the ball park of what to overcome at that speed.

Ben Beacock
Co-Manager
2004 Gryphon Racing - University of Guelph (http://www.soe.uoguelph.ca/uogracing)

[gug]

it does sound good saying that we would still be accellerating at 200kph, dont know when it would stop...

- the problem with the world is stupidity. i'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety lables off of everything and let the problem solve itself?

[Jackson]

10 or 13" TIRES???

how many people use tires this small...? I think most of the hoosiers and goodyears are 18-20" in diameter. The wheels that they are mounted on are 10 or 13", but that doesn't tell you anything.

Just being a snot :P
Brian
Washington State FSAE