How to Read a Motorcycle Spec Sheet: 7 Numbers That Matter and 3 That Don't

Manufacturers write spec sheets the way estate agents write listings. Nothing on the page is false, but the type size tells you what they would rather you not compute. This site exists because I got tired of doing these calculations on napkins, so here is the full method: the seven numbers that predict how a bike actually rides and owns, in the order they matter, and the three that exist mostly to decorate brochures.

1. Power to weight, not power

A 75 hp single in a 156 kg supermoto will destroy a 95 hp twin carrying 30 more kilos out of any real-world corner. Divide peak power by wet weight before you let either number impress you alone. The KTM 690 SMC R at 0.48 hp per kg against the KTM 790 Duke at 0.52 looks close on paper until you notice one of them does it with 20 fewer horsepower. It is the first thing our scoring engine computes, and it is weighted higher than raw power for exactly this reason.

2. Torque, and where it lives

Peak torque tells you less than the rpm it arrives at. 39 Nm at 7,000 rpm rides completely differently from 40 Nm at 5,500. The lower and flatter the torque, the less you work the gearbox in traffic and the more relaxed the bike feels two-up. This is why parallel twins took over the middleweight class: not because they are exciting, but because their torque shows up where commuters actually ride.

3. Wet weight, with a full tank

Watch the footnotes. Some brands quote dry weight, some quote wet without fuel, some quote ready to ride. The differences run to 20 kg, which is the difference between a bike you can pick up after a car park drop and one you stand next to while strangers gather. We normalise everything to wet weight with a full tank in our data, because that is the bike you actually push around.

4. Suspension adjustability

The brand name on the fork leg means little by itself. What matters is whether you can adjust it: a non-adjustable fork is set for a 75 kg test rider and that is the end of the conversation. Fully adjustable units can be set for your weight, your roads and your pace, which is why the Suzuki DR-Z4SM's KYB hardware is one of the few honest arguments for its price. Our methodology scores adjustability with a public tier table.

5. Service and valve intervals

The cheapest bike to buy is often the most expensive to own. Yamaha's CP2 engine in the MT-07 goes 42,000 km between valve checks; KTM's small singles want inspection at 20,000 km, and the DR-Z4SM asks for an oil service every 6,000 km. Over five years of commuting, those gaps are worth more than most discount negotiations. We publish full schedules and costs on every bike's maintenance page, like this one for the 390 Duke, and there is a longer piece on what a motorcycle really costs per year.

6. Seat height, minus the machismo

The forums will tell you seat height does not matter once you are moving. The forums are not holding your bike up at a cambered junction in the rain. If the number is more than 40 mm past your comfortable reach, that is a daily tax on your confidence, and confident riders are faster and safer than tall ones. We compared every seat height in our database so you can shop by inseam without apology.

7. Real tank range

Tank litres times consumption is the only range number that matters, and manufacturers rarely print the multiplication for you. A 9 litre supermoto tank means fuel stops under 200 km no matter what the brochure implies. A 17 litre tank on a frugal single, like the Himalayan 450, is a genuine 450 km day. Compute it before you buy, not at the side of the road.

The three numbers that mostly do not matter

• Top speed. Every bike in this database exceeds every speed limit on the continent. The number measures gearing and courage, not quality.
• Peak horsepower on its own. See number 1. A big number attached to a heavy bike is marketing, not performance.
• Zero to 100 claims. Measured by professional riders on prepared surfaces with the clutch smelling like regret. Your launch will differ.

Every comparison on this site runs these exact priorities through a fixed formula, so you can check my math instead of trusting my taste. Start with any bike and click through to the score breakdown. If you find a number that is wrong, tell me and I will fix it publicly.