Ram 3500 - Spare tire options for 37s.

[rruff]

Here is another one. He got <1% difference between 50 and 10 psi.

 

[IdaSHO]

Thanks for the vids. Its an interesting concept to wrap my noodle around.
I understand the whole tank tread thought, though I still dont beleive it..

 

[p nut]

I'll let you do that experiment! But if the tire isn't slipping on the rim or on the ground, then ya... close to the tread length. I think you'll need to put some air in the tire though, to satisfy those criteria.

Yes the test was crude. It would have been better to deflate it more. But he showed that the difference in travel/rev was very tiny... much less than the radius reduction.

Hmm… I still don’t understand how slapping a flat tire on a rim changes the distance traveled. Rolling a bare rim next to a rim with a flat tire on it, the bare rim will spin faster?
And still doesn’t explain the indirect TPMS system, either.

My conclusion is that a flatter tire definitely changes the “rolling radius,” therefore, distance travelled. But perhaps not a 1:1 ratio I was thinking of. Probably some other factors involved I’m overlooking. Video shows a slight difference, but still a difference. I still think it’s very crude but better than the first video.

Thanks for the engagement and entertainment Conversation was intriguing.

 

[rruff]

My conclusion is that a flatter tire definitely changes the “rolling radius,” therefore, distance travelled. But perhaps not a 1:1 ratio I was thinking of. Probably some other factors involved I’m overlooking.

The "factor" you are overlooking is that the rolling circumference change with pressure is actually a tiny modification of "0".

You can easily do this experiment yourself if you don't trust the ones that others have done.

 

[D45]

I ran a 37" spare in the stock location on my 2004 3500