24" & 36er: How many revolutions per mile?

Does this sound right?:

The circumference of the wheel is found by multiplying their diameter of 24" x 3.141 (PI) which comes to 75.384". In other words, your Unicycle will travel 75.384 inches, or about 6.2 feet, with every revolution of your wheel.

Now we must determine how many wheel revolutions are in a mile. A mile is 5280 feet. Or 63,360 inches. So we divide 63360 by the circumference of 75.384, and the answer is 840.50. So we now know that our wheel must revolve 840.50 times to travel one mile. So we multiply this figure by 25 to get the total number of revolutions for 25 miles and get an answer of 21,012.50. This is the number of revolutions your wheel must turn within one hour to achieve a speed of 25mph.

Then to calculate the circumference for a coker wheel, we would multiply 36" x 3.41 which would be 122.76, or 10.23 feet per revolution. By using the same formula for determining how many revolutions per mile, we divide 63,360 inches by 122.76 and we then get 516. If you do a century ride on your 36er, you would have made 51,613 revolutions! No wonder it’s such a fantastic work out! [B]:slight_smile:

Btw[/B], I know these numbers are not exact, due to irregularities of road surfaces and/or trail terrain, and also different tires will alter the data a bit as well. But it’s a good estimate imo. :slight_smile:

Your coker numbers are off because you used 3.41 instead of 3.14 for pi.

I think in reality you would have to pedal more than that though because unicycles don’t really go straight. The amount you wobble back and forth is probably pretty significant after 25 miles (or whatever).

This thread reminds me why I don’t like to unicycle for more than a few miles :wink:

This is just the kind of thing that consumes my thoughts in the wee hours of the night. It’s better than counting sheep to put me to sleep for sure.

Woops! You’re right, I juxtaposed 'em! But yeah, you ride mostly flat/street, so I wouldn’t want to ride my 19" for ANY kind of serious distance either! And I’ll tell ya, doing a 20 mile MUni trek a few weeks back, with big elevation changes and technical terrain was monumentally more punishing than a mere 50 mile coker ride on mostly smooth ground! :o

Yeah but I ride muni sometimes and I’ve had a 36" before too. I just think there’s a limit to how long I can sit on a unicycle seat and be happy. Some seats feel nice to sit on for a few miles but even comfortable seats hurt a lot after a few hours (at least to me). I’d rather keep muni trails difficult and under 5 miles because then it’s more of a session than an all day journey. I know everyone’s interests are different but after unicycling for multiple years I don’t find it that fun to just pedal around for a long time :stuck_out_tongue: (sorry not that relevant)

Yeah, most of my MUni rides are in the 4-9 mile range and I also love sessioning and having a blast on technical terrain. But I also like to really challenge myself on longer rides of the same intensity, and make it a whole day adventure. It’s like anything else youl really love, and almost to the point of obsession. I just can’t get enough! :smiley:

Oh yeah, and with MUni, since there’s drops, hops, jumps, gaps, etc., I’m not continuously on the saddle nearly as much compared to cokering, where you are pretty much ALWAYS on the saddle while riding. :slight_smile:

I have created a spreadsheet for these calculations and provided it in Excel (.XLS) and Open Office format (.ODS).

Unicycle Rotations.zip (18 KB)

No, you transposed them. They were juxtaposed already. :sunglasses:

How much less do both feet have to travel on 126mm cranks than on the 150mm cranks in 25 miles on a coker? :sunglasses:

I’m just askin’

For non-geared, the number of “circles” your feet make would be the same; one for each wheel revolution-regardless of crank size. But the shorter the cranks, smaller the circles. As for how much less “travel” I would guess about 75.36mm per revolution less. :slight_smile:

You forgot to multiply by two. Cranks lengths are radii and you wanted diameter.
So 150.72mm per revolution.

On a Coker the rough figures are pretty easy to think about. 10mph on a Coker is very close to 100rpm. At that speed, to do one mile you’d be riding for 1/10th of an hour, or six minutes. So you’d have to pedal 6x100 revs in that 6 minutes. 600 revs per mile.

Of course the 10mph/100rpm ratio is not exact, but it happens to be pretty close for a 36er - good enough for a quick estimate of revs. As people have pointed out, lots of other variables affect it anyway so it’s probably a bit pointless trying to be any more accurate.

For other wheel sizes, adjust that 600 revs/mile proportionately. (so a 24" would be 2/3 of the size, needing to do 3/2 as many revs per mile, or 900 - but of course a 24" muni isn’t 24" diameter…).