Revolutions per mile for trailer tires

[Lion hunter]

Just cause it's late and I got nothing better to do I decided to see how many revolutions per mile my trailer tires spin compared to my truck. I run 265/70/17 on my truck and 5.30x12 on my trailer. The circumference of the tires are 99.293" for the truck and 65.94 for the trailer. 63360" in a mile. My truck tire makes 638 revolutions per mile and the trailer makes 961. So at a given spot the trailer tire is striking the pavement 33% more times than the truck.

Just something else to add to my encylopedia of worthless knpwledge )

 

[Bob_VT]

Re: Revolutions per mile for trailer tires

Just cause it's late and I got nothing better to do I decided to see how many revolutions per mile my trailer tires spin compared to my truck. I run 265/70/17 on my truck and 5.30x12 on my trailer. The circumference of the tires are 99.293" for the truck and 65.94 for the trailer. 63360" in a mile. My truck tire makes 638 revolutions per mile and the trailer makes 961. So at a given spot the trailer tire is striking the pavement 33% more times than the truck.

Just something else to add to my encylopedia of worthless knpwledge )

You get the following.........

Mathematics A
Spelling C-

For extra credit consider this question. When you make a 90 degree turn (either left or right), how much faster is the outside tire traveling in distance and what is the speed difference from the inside tire?

 

[kenmyfam]

Re: Revolutions per mile for trailer tires

For extra credit consider this question. When you make a 90 degree turn (either left or right), how much faster is the outside tire traveling in distance and what is the speed difference from the inside tire?

And for a distinction consider the ongoing tire wear per mile reducing the diameter of the tire therefore constantly though fractionally increasing the revolutions over the distance traveled.

 

[Lion hunter]

Re: Revolutions per mile for trailer tires

LMAO!!!

THanks Bob! Fingers get fat at 1:00 am

Kenny: I had to cheat my way through calculus in college so theres no way I'm figuring that one out. Sounds like the exponential growth of animal populations we would have to do.

If my math is correct at anything other than a straight line your inner and outer turn radius would remain a constant distance apart from each other.

And example would be if I was turning in a circle with my truck and trailer and the inner turn radius was 60'. The diameter would be 120' so the circumference is 377' (4524"). If the trailer is 10' wide the outer radius would be 70'. so the circumference is 440' (5724"). Since the trailer tire circumference is about 66" the inner tire would make 68.5 revolutions and the outer tire would make 86.72 revolutions. So about 20% more travel to the outer tire. I think this should be constant for anything other than a straight line.

 

[kenmyfam]

Re: Revolutions per mile for trailer tires

LMAO!!!

THanks Bob! Fingers get fat at 1:00 am

Kenny: I had to cheat my way through calculus in college so theres no way I'm figuring that one out. Sounds like the exponential growth of animal populations we would have to do.

Funny
My only calculation is how much beer I need to buy for the weekend !!!

 

[Bob_VT]

Re: Revolutions per mile for trailer tires

LMAO!!!

THanks Bob! Fingers get fat at 1:00 am

Kenny: I had to cheat my way through calculus in college so theres no way I'm figuring that one out. Sounds like the exponential growth of animal populations we would have to do.

If my math is correct at anything other than a straight line your inner and outer turn radius would remain a constant distance apart from each other.

And example would be if I was turning in a circle with my truck and trailer and the inner turn radius was 60'. The diameter would be 120' so the circumference is 377' (4524"). If the trailer is 10' wide the outer radius would be 70'. so the circumference is 440' (5724"). Since the trailer tire circumference is about 66" the inner tire would make 68.5 revolutions and the outer tire would make 86.72 revolutions. So about 20% more travel to the outer tire. I think this should be constant for anything other than a straight line.

The easiest solution is to count your left and right turns...... keep a tally and if you make an equal amount the tires have covered the same distance

 

[Lion hunter]

Re: Revolutions per mile for trailer tires

I just turn left on Mon, Wed, and Fri. Right on Tues, Thur, and Sat. And Straight on Sunday.

 

[PitchFork]

Re: Revolutions per mile for trailer tires

Funny
My only calculation is how much beer I need to buy for the weekend !!!

2nd That

 

[bruceb58]

Re: Revolutions per mile for trailer tires

In California, everything turns left.

 

[BTMCB]

Re: Revolutions per mile for trailer tires

In California, everything turns left.

Ain't that the sad truth.............

 

[H20Rat]

Re: Revolutions per mile for trailer tires

LMAO!!!

And example would be if I was turning in a circle with my truck and trailer and the inner turn radius was 60'. The diameter would be 120' so the circumference is 377' (4524"). If the trailer is 10' wide the outer radius would be 70'. so the circumference is 440' (5724"). Since the trailer tire circumference is about 66" the inner tire would make 68.5 revolutions and the outer tire would make 86.72 revolutions. So about 20% more travel to the outer tire. I think this should be constant for anything other than a straight line.

couple other variables you need to account for. To calculate the path your trailer actually takes, you need to know both the distance from the ball to the rear axle of the tow vehicle, as well as the ball to the axle of the trailer. I've seen the entire thing worked out before, it isn't pretty! Its the type of math that involves lots of random squigly lines! (disclaimer, undergrad minor in math and orbital mechanics/major in computer science)

Think of it this way, given the right tow vehicle/trailer combination, you can make a turn so tight that the inside trailer tire will stop, or even go backwards!

 

[Riverboat_Mickey]

Re: Revolutions per mile for trailer tires

You get the following.........

Mathematics A
Spelling C-

For extra credit consider this question. When you make a 90 degree turn (either left or right), how much faster is the outside tire traveling in distance and what is the speed difference from the inside tire?

Not to nit-pick... but the mathematics grade should be no higher than B-.

Any point on the trailer tires will strike the ground ~50% more than a point on the truck tires!

And as for the extra credit question: you need to know the radius of the turn, axel length, speed of tow vehicle, length from hitch(pivot point) to trailer axel in order to answer correctly!

- Mike


edit: smokingcrater types a little faster than I. (yes the axel to hitchpoint of the tow vehicle as well)

 

[bruceb58]

Re: Revolutions per mile for trailer tires

Not to nit-pick... but the mathematics grade should be no higher than B-.

And as for the extra credit question: you need to know the radius of the turn, axel length, speed of tow vehicle, length from hitch(pivot point) to trailer axel in order to answer correctly!

Spelling C-. Axel is a figure skating maneuver.

 

[Riverboat_Mickey]

Re: Revolutions per mile for trailer tires

Spelling C-. Axel is a figure skating maneuver.

Hee hee!! I was wondering why my phone kept trying to capitalize it! Would you believe me if I said I was trying to maintain the theme of the OP!

 

[nlain]

Re: Revolutions per mile for trailer tires

And if you change brands of tires you have to recalculate the numbers to keep them correct. Just because the different brands of tires all have the same size on them does not make them the exact same size. Go to several tire manufacturer sites and check the measurements.

 

[Bob_VT]

Re: Revolutions per mile for trailer tires

Not to nit-pick... but the mathematics grade should be no higher than B-.

Any point on the trailer tires will strike the ground ~50% more than a point on the truck tires!

And as for the extra credit question: you need to know the radius of the turn, axel length, speed of tow vehicle, length from hitch(pivot point) to trailer axel in order to answer correctly!

- Mike


edit: smokingcrater types a little faster than I. (yes the axel to hitchpoint of the tow vehicle as well)

Grading on a bell curve

 

[Riverboat_Mickey]

Re: Revolutions per mile for trailer tires

Grading on a bell curve

A lost art! IMHO!

 

[Lion hunter]

Re: Revolutions per mile for trailer tires

I didn't attempt to calculate the difference in turning radius between the truck and trailer that is way beyond my math skills . I was only looking at one tire compared to the opposite tire on the same rig. Ok thats my math overload for the year.

 

[kenmyfam]

Re: Revolutions per mile for trailer tires

The good news is I did manage to calculate how much beer I needed but now it's all gone so I am busily re-calculating again

 

[roscoe]

Re: Revolutions per mile for trailer tires

FYI, info that can come in handy, occasionally.

mph x 1.5 = feet per second