Big Tires pulling Small tires.

[SweetLou]

A friend of mine asked me a question that I could not answer about his tires and towing. He has a small trailer weighing about 300 lbs unloaded and can carry up to 1000lbs total. Now the trailer has 13 inch wheels on it and his truck is a Dodge with 17 inch wheels. If he is going 60 mph, how fast do you suppose his 13 inch wheels are going? I suspect he means revolutions but you get it. He wasn't sure he could go that fast or faster in fear of burning up the trailer bearings. I really could not answer his question other than to say get them greased with good grease and try it out. Stop every 10-20 miles and see how warm they get. Of course I told him to put some weight in it as well to simulate the trip load and see. Anyone else know how to answer him?

[Grit_dog]

noteven wrote:
Goodyear 24x8 13" aircraft tire would fix the "tire issue"


24x8.0-13 18 TL 230mph 12500lbs 285psi


Mod the axle to accept the aircraft wheel and that...

Probably wouldn't need 285psi to hold up a boat.

Aircraft tire data

Great solution….:R

[LanceRKeys]

JRscooby wrote:

NRALIFR wrote:

SweetLou wrote:
So the tire spins 1.3 times faster but we really don't know the speed of those small tires? Can we say 1.3 times faster than the truck, or 78 mph?

No, you can’t.

That would be nothing more than a variation of the trick question: “Which weighs more, a pound of feathers, or a pound of lead?”

The tires spin at a higher RPM, but the MPH is the exact same as the truck pulling it. :S

:):)

A track loader is moving 8 MPH. How fast is the pad on the ground moving?

The bottom of the track isn’t moving at all relative to the ground, same with the tire on a truck, the bottom of the tire on a truck isn’t moving for the moment in time it is touching the ground.

If a truck is moving 70mph, the bottom of the tire is moving 0mph, and the top of the tire is moving 140mph.

[Fisherman]

Campinfan wrote:
When I was a cop, I stopped a guy for speeding. When he went to court, he said he was a rocket scientist (and I think he really was based on where I was a cop) and that my radar clocked his tires which were smaller than his car and the tires were going faster than the car which is larger. The judge at one point, may have been off the record, said in a joking manner that we were doing "radar" all wrong. I replied that is the reason we have stop signs and red lights--so the car can catch up to the tires.

Well gotta admit, he tried and lost, but it's a good one.

[noteven]

Goodyear 24x8 13" aircraft tire would fix the "tire issue"


24x8.0-13 18 TL 230mph 12500lbs 285psi


Mod the axle to accept the aircraft wheel and that...

Probably wouldn't need 285psi to hold up a boat.

Aircraft tire data

[Grit_dog]

stevemorris wrote:
LOL, i can remember when some cars had 12 inch wheels and the old austin mini had 10"!!

I can’t, but sure would suck to have a car with 10-12” wheels!

[Campinfan]

When I was a cop, I stopped a guy for speeding. When he went to court, he said he was a rocket scientist (and I think he really was based on where I was a cop) and that my radar clocked his tires which were smaller than his car and the tires were going faster than the car which is larger. The judge at one point, may have been off the record, said in a joking manner that we were doing "radar" all wrong. I replied that is the reason we have stop signs and red lights--so the car can catch up to the tires.

[stevemorris]

LOL, i can remember when some cars had 12 inch wheels and the old austin mini had 10"!!

[SweetLou]

deltabravo wrote:

SweetLou wrote:
If he is going 60 mph, how fast do you suppose his 13 inch wheels are going?

60 MPH.

If the trailer is going faster than the truck, it came unhitched while going down hill and the trailer is passing him and the safety chains are busted


If the trailer is going slower than the truck, it came unhitched while on flat ground or going downhill and the trailer is way behind him now him and the safety chains are busted. He better plan on taking the next exit and circling back to the previous exit / on ramp so he can retrieve the trailer.

Turn that work into your math teacher

[deltabravo]

SweetLou wrote:
If he is going 60 mph, how fast do you suppose his 13 inch wheels are going?

60 MPH.

If the trailer is going faster than the truck, it came unhitched while going down hill and the trailer is passing him and the safety chains are busted


If the trailer is going slower than the truck, it came unhitched while on flat ground or going downhill and the trailer is way behind him now him and the safety chains are busted. He better plan on taking the next exit and circling back to the previous exit / on ramp so he can retrieve the trailer.

[blt2ski]

Grit dog wrote:

time2roll wrote:
CA speed limit is 55 mph for all vehicles towing.

Significance or relevance?

Probably neither. No different than here I Wa st where rigs under 10k g w or no towing can go 70 where marked. Towing or licensed over 10k gvw you can only go 60mph max anywhere. That include licensed rig empty under 10 k, but licensed over 10k.

Marty

[Grit_dog]

time2roll wrote:
CA speed limit is 55 mph for all vehicles towing.

Significance or relevance?

[Grit_dog]

SweetLou wrote:
Actually his old trailer is an old U-haul but he says it doesn't say that 45 mph rule anywhere. The tires on it are new and for a car since he really doesn't weigh it down any. The tire brand and specs say 937 lbs at max pressure which I don't know what that is. So the tire spins 1.3 times faster but we really don't know the speed of those small tires? Can we say 1.3 times faster than the truck, or 78 mph?

Yes, exactly.
Except the trailer is still going the same speed, but comparing the rpms of the wheel, to something everyone can grasp (mph) is accurate.

Like mooky said, them 10" snomachine/pontoon boat trailer wheels hold up reasonably well at higher highway speeds, although not near as well as larger diameter tires.

PS, the 45mph uhaul max was/is to keep people who don't tow much, driving slower, IE less accidents and liability. Nothing to do with the trailer being able to not go faster without coming apart.

[SweetLou]

theoldwizard1 wrote:
Bottom line. Re-pack those bearings regularly !

This is exactly what I told him. Also told him to do it himself. I pulled recently cargo trailer wheels that had been done last summer by a place I know that I thought did good work. I was amazed at what they considered packed. Do them yourself save and know.

[SweetLou]

NRALIFR wrote:

SweetLou wrote:
So the tire spins 1.3 times faster but we really don't know the speed of those small tires? Can we say 1.3 times faster than the truck, or 78 mph?

No, you can’t.

That would be nothing more than a variation of the trick question: “Which weighs more, a pound of feathers, or a pound of lead?”

The tires spin at a higher RPM, but the MPH is the exact same as the truck pulling it. :S

:):)

Ya dun caught me