The project behind the calculators.
Hello, I'm Robin and I created PolkaDOTBike — I built it, ride with it and maintain it. I've been on road bikes a long time: long enough to remember when a 53/39 chainset and an 11–23 block was simply what you got, and when fitting a triple was how you found a climbing gear that wouldn't break you. I ran a 52/42/32 for exactly that reason.
My background is in engineering, and it shapes how I approach all of this: I like numbers I can trust and machines I understand. I maintain my own bikes too — fitting the cassettes, setting the derailleurs, riding the result — so the calculations on this site come from someone who works on the actual hardware, not just the maths.
Gearing has moved on a long way since — compact chainsets, wide-range cassettes, 1x drivetrains — and a fair bit of this site comes from wanting to make proper sense of how far, and to help other riders do the same.
The reason is that I keep wanting these numbers for my own riding. Power meters have become far more prevalent, and since I started using one I've found a real interest in seeing what my numbers are as I climb — and how they'd stack up on the climbs of the Grand Tours. This site is my way of assessing what I can actually achieve, and the gear calculator lets me try different combinations before spending any money on them: what would work, what might work, and what definitely won't.
So I built the calculators I wanted instead: clean, quick, and able to answer all the questions. I hope they're beneficial to you too.
The name is of course taken from the iconic Tour de France King of the Mountains jersey — first worn at the 1975 Tour — because the climbing side of the sport is what I enjoy most. It's why the site has full Tour and Giro climb browsers — every stage, with gradients and profiles — and a planner that tells you what a climb will take for you, not for a professional. If a stage finishes on a brutal ramp, I want to know what gear I'd need to get up it. Now I can, and so can you.
The gearing side of the maths is exact — a given chainring, cog and wheel size produce the same result every time, and that part you control completely with your selections. It's the rider side that moves: power, aerodynamics, weight, wind and road surface. The inputs let you set those as realistically as you can, but they're estimates of variables that change from ride to ride and can't be pinned down by a website, so treat the speed and power figures as a very good guide rather than gospel. If something looks wrong, or you can think of a way to make a tool better, I'd genuinely like to hear it.