🏍️ BuildToDoGood Motorcycle

Motorcycle math and honest gear takes. For riders who change their own chain and want to know exactly when it's worn out, not when the manual says to replace it.

Manuals are conservative because manuals are written for liability, not riding. Service intervals are halved. Tire pressures are split-the-difference. Chain replacement is recommended when the chain still has 30% life left. Real-world numbers are different and there's no good reason to leave money on the table because Honda doesn't trust you to be careful.

These tools are the real numbers. The chain wear calculator measures actual stretch, not the dealer's eyeball. The gearing calculator tells you what a -1 front sprocket really does to your acceleration and your top speed. The tire pressure recommender adjusts for ambient temp, load, and riding style.

Tools

Chain Wear Calculator Measure 16-link span (or 17, depending on chain). Convert to wear percentage and remaining miles by chain type (X-ring vs O-ring vs non-sealed). Tells you when it's actually time, not when the dealer says. Gearing Change Predictor soon Front and rear sprocket changes: what happens to top speed, acceleration in each gear, RPM at 70 mph. With chain length recalculation for the new gearing. Tire Pressure Calculator soon Adjusted for ambient temp (cold-set pressure rises with temperature), load (single vs two-up), and riding style. Sport, ADV, and touring profiles. Lean Angle and Corner Speed soon Given a corner radius, how much lean angle for a given speed. With practical "but you should be lower" advice because real-world surface conditions never match physics class.
Plain note about money: Some product links are affiliate (eBay Partner Network). Small commission on purchases. Doesn't change your price. Gear reviews are based on actual road miles. The "use the OEM part" recommendations sometimes earn me less than the aftermarket alternative; OEM still wins for things like chains and brake pads on most bikes.