Gear Inches / Drivetrain software

"malcomm" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Some interesting software for figuring out gear inches and ratios etc
from your drivetrain.
Tells you the max speed in each gear combination adjusted for
cadence....
Runs on the PC

www.income-software.com/GearCalc/

Seems to be a bad link.

Quoted message said:

--
malcomm

FWIW, I've recently added a Gearing Calculator to my CycliStats ride log and
training diary ( http://www.CycliStats.com ). You can see a screen shot of
the Gearing Calculator on this page:
http://www.shastasoftware.com/CycliStats/tools.htm (the Gearing Calculator
is about halfway down the page).

--
~_-*
....G/ \G
http://www.CycliStats.com
CycliStats - Software for Cyclists

malcomm said:

Some interesting software for figuring out gear inches and ratios etc
from your drivetrain.
Tells you the max speed in each gear combination adjusted for
cadence....
Runs on the PC

www.income-software.com/GearCalc/

Took me about 20 minutes of doodling in a spreadsheet
(the OpenOffice.org one in this case) to get the same
effect.

Cut and paste shown below. The notations on some of the
rear gears are old; I now warm up in 52/18 and then do the
entire ride in 52/16, thus using the hills for anaerobic
intervals.

--Blair
"Runs on bananas."

Ratios
42 52
24 1.8 2.2
22 1.9 2.4
20 2.1 2.6 warmup/down
18 2.3 2.9 Cruise
16 2.6 3.3 Sprint
14 3.0 3.7 Descent

inches/crank @ 27 tire compressed 1/8 in
(unused gears deleted from table)
24 147
22 160 199
20 176 218
18 243
16 273
14 312

cranks/mile
24 431
22 395 319
20 359 290
18 261
16 232
14 203

Mph @ 84 rpm
24 11.7
22 12.8 15.8
20 14.0 17.4
18 19.3
16 21.7
14 24.8

I was going to save a .csv file and post it, but apparently
that doesn't preserve the formulae.

It's pretty simple, though.

Each gear_ratio is just chain_ring_teath/rear_cog_teeth.

Then each inches_per_crank is just 3.14*(wheelsize-2*compression)*gear_ratio.

Then each cranks_per_mile is just 5280*12/inches_per_crank.

Then each mph@rpm is just 60*rpm/cranks_per_mile.