Cost-per-watt analysis: maintenance vs equipment upgrades. The data makes the case.

I went down a rabbit hole on drivetrain friction testing and wind tunnel data, and the results surprised me.

A clean chain runs at about 97.6% efficiency. Dried mud drops that to 92.8%. At 250 watts, you are losing roughly 12 additional watts to friction. After a truly muddy ride, the penalty reaches 20-30W according to Friction Facts testing.

Then there is aerodynamics. Swiss Side actually put a dirty bike in the wind tunnel alongside a clean one. Even light mud on a non-aero gravel frame created a measurable drag penalty. Cable housing generates about 1W of drag per 10cm at speed.

The cost-per-watt comparison is what really got me. Chain cleaning saves watts at $2.50-5 per watt. An aero frame upgrade? $250-355 per watt.

I wrote up the full data with sources from SILCA, CeramicSpeed, Swiss Side, Hambini, and others: Aero Efficiency: Why Clean Components Are Faster Than Dirty Ones in the Wind Tunnel

What is your post-ride cleaning routine? Curious how many of us are actually consistent about this.