Question for the math whiz kids.

With a 3.25:1 rear ratio and a 30 3/4 tall tire, what would the final ratio be? Thanks Ron

Reply to
Ron Butts
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Is this meant to be a trick question? The ratio will not change no matter what the tire size. For every

3.25 turns of the driveshaft, the tire will still turn one turn. The tire will cover more or less distance based on the tire's size (circumference), but the ratio does not change. If you want to compare the difference in rpm based on different tire sizes, just use the ratio of diameters or circumferences of the different tires as a factor of change.
Reply to
studegary

Gary For those of use who are mere mortals, all I wanted to know what would be the tire speed ratio in comparision to the final drive ratio of 3.25:1. If I'm reading your statement correctly, the actual ratio for distance traveled versus tire size does not change or are you justing to correct someone?

Is this meant to be a trick question? The ratio will not change no matter what the tire size. For every

3.25 turns of the driveshaft, the tire will still turn one turn. The tire will cover more or less distance based on the tire's size (circumference), but the ratio does not change. If you want to compare the difference in rpm based on different tire sizes, just use the ratio of diameters or circumferences of the different tires as a factor of change.
Reply to
Ron Butts

Reply to
satdoc2 via CarKB.com

Reply to
satdoc2 via CarKB.com

'pends on if you have an OD unit or straight drive :)

nate

Reply to
Nate Nagel

Hey Nate I'm going to have 3 dumptruck loads of mulch dumped in your drivway as a Christmas present. :)

Reply to
Ron Butts

"Ron Butts" wrote

Christmas present. :) _____________________ Watch out. Lot of dump trucks have a 2-speed rear end, and Nate prolly knows how to do that math too...

(Foghorn Leghorn to Chicken Hawk: "Never mind, Einstein. I just might be in there.")

Reply to
comatus

Reply to
Nate Nagel

As long as the driver takes away an equal quantity of the decomposed stuff, I'm happy :)

nate

(driveway is still buried, but it's gett> Hey Nate

Reply to
Nate Nagel

First time in years I've heard those two words used together. Coal and shovel

Nate Nagel wrote:

Reply to
Transtar60

My grandparents still heated their house with coal up until the mid

90's; of course it didn't hurt that they literally lived across the street from a big coal mine... (rural PA)

nate

Transtar60 wrote:

Reply to
Nate Nagel

Perhaps I should have rephrased the question. If you have a 3.25:1 rear ratio with 27 in. dia. tires and you put on 30 3/4 dia tires, what would the equivalent ratio be? 3.20? 3.15? 3.10?

Reply to
Ron Butts

It was common around here too until the mid fifties or so I've been told. Maybe earlier as everybody switched to natural gas.

All the coal ash that was > My grandparents still heated their house with coal up until the mid

Reply to
Transtar60
2.85

Reply to
Jerry Forrester
2.86 (I rounded up, due to inflation, which they say is under control ). Jeff

"Jerry Forrester" wrote:...

Reply to
Jeff Rice

_______________ I often wonder about that. My family was in the coal business for 50 years--I still keep about 10 tons in stock. My uncles, in their retirement, amused themselves by heating our 40 x 50 barn-shaped commercial garage, apartment upstairs, with a coal stove. A true stove, with heat pipes coming off the jacket, not just a point-heater. The apartment, at the end of the ducts, stayed clean enough, but after my uncle died it took me about a year to get the last of the coal dust out of the downstairs, around the furnace, in the joists, in the tool bins, etc. etc. The furnace was tight and clean, and the chimney too. They were not sloppy about firing it. I had about decided that they must have cleaned the chimney pipes inside the garage a few times without mentioning it.

I got rid of the stove, but have a couple of woodburner airtights adapted to handle coal (you don't use it the same as firewood). I don't notice any extreme dust production now. Where did all that coal-smoke dust come from?

FWIW, my dad remembers coming across the river on our high-level suspension bridge in the 30's, when all houses were heated with coal, and seeing a black pall over the whole east side every morning as inexpert homeowners put cardboard and corncobs to their furnaces to stoke up the coal in a hurry. That all vanished fast in the 1950's (along with our residential coal accounts) and the air got real clean all of a sudden. Factories and refineries got all nice in that period, too, and by the 70's the air in northern Ohio had never been so clean. Leaving AGW completely out of it, it makes you wonder why reported instances of asthma and chronic pulmonary diseases could be rising so fast, when the worst air pollution went away 40 years ago.

Incidentally there is a long-running debate between old Pa. and Ohio coal drivers over whether a wooden or steel dump bed is better for coal.

Reply to
comatus

It has rear disc brakes and I'm thinking about gluing 80 grit sandpaper to the disc pads for better friction co-efficient :)

Are you going to change your rear brake shoe size at the same time or keep the same size, but with a different co-efficient of friction?

Reply to
Ron Butts

With the new information, I can see that you are driving at what the ratio will appear to be as compared to having the previous tires. I believe that the answer to that question is 2:85.1. I wasn't trying to be wise before. Without the other tire size, we couldn't come up with this answer.

Reply to
studegary

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