Here is a "competitor" which I have found extremely useful when choosing drivetrain parts: http://www.gear-calculator.com
These are really helpful if you have a bike you mostly like and want to upgrade the gears, or if your current bike doesn't have the gears you need. It has become especially important during the recent trends of moving from 3x front gears to 2x to 1x.
I still use his site as well. In fact, I used it just two days ago to see how much different using a mid-compact (52/36) is from a "standard" compact (50/34). Need all the help I can get up steep hills such as Mt. Diablo.
Would someone explain to me why this information is useful? Maybe it is because English is my second language, but I didn't understand the meaning of the displayed information. I cycle a lot and it looks interesting.
In my opinion, this visualization is not particularly compelling if you don't already know what you're looking at, and I can relate to your sentiment of confusion.
This is a tool for analyzing and comparing differences between drivetrain setups. A bicycle drivetrain is typically composed of a single gear, or two or three gearing choices "up front" (on or near the crankset) and either a single-speed "rear", or anywhere from two to 30 (!) [1] selectable gears at the rear hub.
The various "output" modes from this tool are all derived from the Gear Ratio, usually simply the ratio of the number of teeth "up front" to the number of teeth "in back" for any given selected gear.
By entering multiple drivetrain setups, you can quickly compare overall range between different drivetrains. You can also see the "steps" between different gears within a given drivetrain, which tells you how many pedal cadence choices you'll get within a given comfort zone for the bike's intended riding purposes.
[1] SRAM's DualDrive 3x10 internally-geared hub with a standard cassette and derailleur.
I avoided mentioning it because I couldn't remember off the top of my head when writing the above comment, but Pinion also makes a gearbox that sits next to the crankset and offers up to 18 gearing choices!
been riding bikes for 33 years daily (up to 65km/h every morning last year (ok 50+km/h for 1 km on light slope on the journey to be honest)) and I am as clueless as you.
Displayed information is basically the speed you have for given the size of the wheel, given the rpm (turns per minutes) for each gear and plates.
In school you learn stupid stuff like C = 2pi(R+dr) (R=size of wheel (70cm) + tire (2.5cm) you take the ratio of plate/gear and deduce your gear by making rpm * 2 * pi * (R + dr ) * number of teeths on front / nomber of teeth back. It is basic math.
You can express everything in SI and apply (m/s) x 3.6 to get km/h.
If you do a bit of mental calculus it is easy.
If you actually ride bike it is useless, after some years, your legs know stuffs.
Like the fashion of compact pedalier is freaking stupid and it is impossible to find a decent bike that is not overpriced in north america since lance Armstrong won the tour de france, and that it has put a lot of douchebags with too much money and not enough civility on bikes.
But I guess this if off topic...
Like the fact my wife and I nearly die every day commuting on our bikes and that we have at least 2 accidents a year.
Sometimes with people in SUV going out of town with their 11k$ bikes attached at the rear.
As of 30 Dec 2015 @ 0822 hrs US CST, the link generates a Traffic Quota Exceeded error. Heck, that's one of the reasons why I still occasionally peddle to work.
