Author Topic: Help with gearing  (Read 2848 times)

0 Members and 1 Guest are viewing this topic.

Offline Schiveley89

  • Newbie
  • *
  • Posts: 7
  • Karma: 0
    • View Profile
Help with gearing
« on: June 04, 2021, 04:27:47 pm »

Looking for help on getting a base line set up for my gearing on my fx mower. Vanguard 35 built,pushing 6500 rpm,noram star clutch 15 tooth
1/10 mile track,8" rear wheel ,need that middle speed and torque set up.

Offline PJG56

  • Turf Warrior
  • **
  • Posts: 576
  • Karma: 4
  • Gender: Male
    • View Profile
Re: Help with gearing
« Reply #1 on: June 06, 2021, 12:03:42 pm »
 I would start with a final ratio of about 6-1 and work from there
Paul Guptill  (oppy) #238modX
2012 slmra mowstock champion(builder/owner)

2013 slmra mowdified champion(builder/owner)
2013 ARMA national champion Mod-X(builder/owner)
2014 ARMA national champion Mod-X(builder/owner)
2014 All American Champion Mod-X/CP(builder/owner)
2014All American Champion FXT (engine builder)
2014 All American 2nd place SP(builder/owner)
2015 All American 2nd place BP (builder/owner)
2016 OutlawTriple Crown FXT Champion (engine builder)

Offline Schiveley89

  • Newbie
  • *
  • Posts: 7
  • Karma: 0
    • View Profile
Re: Help with gearing
« Reply #2 on: June 06, 2021, 07:50:59 pm »
Paul,my last one was a 5:1
It went...15 to 30 then
16-48

Now it's a smaller track,150-180' straights..clutch will most likely be a 15 tooth
Any sprocket tooth ideas?
Horizontal Briggs twin

Offline PJG56

  • Turf Warrior
  • **
  • Posts: 576
  • Karma: 4
  • Gender: Male
    • View Profile
Re: Help with gearing
« Reply #3 on: June 08, 2021, 08:57:15 am »
Paul,my last one was a 5:1
It went...15 to 30 then
16-48

Now it's a smaller track,150-180' straights..clutch will most likely be a 15 tooth
Any sprocket tooth ideas?
Horizontal Briggs twin

Your math is wrong.The ratios you quoted =6-1 (30 divided by 15=2,48 divided by 16=3 ,2x3=6-1 final ratio
Paul Guptill  (oppy) #238modX
2012 slmra mowstock champion(builder/owner)

2013 slmra mowdified champion(builder/owner)
2013 ARMA national champion Mod-X(builder/owner)
2014 ARMA national champion Mod-X(builder/owner)
2014 All American Champion Mod-X/CP(builder/owner)
2014All American Champion FXT (engine builder)
2014 All American 2nd place SP(builder/owner)
2015 All American 2nd place BP (builder/owner)
2016 OutlawTriple Crown FXT Champion (engine builder)

Offline PJG56

  • Turf Warrior
  • **
  • Posts: 576
  • Karma: 4
  • Gender: Male
    • View Profile
Re: Help with gearing
« Reply #4 on: June 08, 2021, 09:14:16 am »
15-30 and 16-48 =6-1 final ratio
15-30 and 15-48 =6.4-1 final ratio
15-30 and 14-48 =6.86-1 final ratio

Engine rpm divided by final ratio = axle rpm x tire rollout x5 divided by5280 = mph

example 6500 rpm divided by 6 =1083 x 48=51984 x 5  =259920 divided by 5280 =49.23

Hopefully you can do your own gear ratio's now
Paul Guptill  (oppy) #238modX
2012 slmra mowstock champion(builder/owner)

2013 slmra mowdified champion(builder/owner)
2013 ARMA national champion Mod-X(builder/owner)
2014 ARMA national champion Mod-X(builder/owner)
2014 All American Champion Mod-X/CP(builder/owner)
2014All American Champion FXT (engine builder)
2014 All American 2nd place SP(builder/owner)
2015 All American 2nd place BP (builder/owner)
2016 OutlawTriple Crown FXT Champion (engine builder)