Gear math for riders who count every tooth.
Every upgrade promises speed. This is the receipt: seven proven ways to go faster, ranked by dollars per watt saved — from a position change that costs nothing to wheelsets that charge you three hundred dollars for every single watt. Tap any row for the test behind the number, then add your own upgrade and see where it lands.
Sorted by $ per watt. Tap a column header to re-sort; tap a row to see the note behind it.
Read the fine print first: Watts measured at ~25 mph (40 km/h); aero savings shrink at lower speeds. Prices are rough current retail.
Six of the seven upgrades cost $25 per watt or less. Then the curve falls off a cliff — the last few watts are the expensive ones. Bars are on a log scale, or the small stuff would be invisible.
Per watt of drag or rolling resistance saved, at ~25 mph (40 km/h). Your custom upgrades appear here too, in orange.
Got a purchase in mind — or one you’re already justifying? Enter what it costs and the watts it claims to save, and it takes its place in the ranking above.
Watts saved must be above zero — a $/watt figure needs watts to divide by. Be honest with the claim; marketing watts and tunnel watts are different animals.
The ranking is simple. What it means for your wallet takes two more ideas.
The top of the table fights rolling resistance and drivetrain friction — chain wax, tubes, tires. Those savings are there at almost any speed. The aero rows (socks, helmet, wheels, and your position in the drops) are measured at ~25 mph (40 km/h), and aero drag grows with the cube of speed — ride at 18 mph (29 km/h) and those watt figures shrink a lot.
The first watts are nearly free: position, a clean chain, decent rubber. After that the price per watt climbs by orders of magnitude — deep-section wheels cost about 93× more per watt than a waxed chain. That doesn’t make wheels a bad buy; it makes them a last buy, once the cheap watts are already in your legs’ account.