RACE-DAY WHEELS

If you want to speed up your bike leg, a wheel upgrade could knock minutes off an iron-distance race time compared to training rims. But which pair should you choose? Jack Sexty tests nine...

- JACK SEXTY

RIM

Comprising of the upper and outer edge, race wheel rims come deeper than training wheels to cheat the wind.

HUB

The central part of the wheel consists of the axle, bearings, and hub shell to which spokes are attached.

JARGON BUSTER

WATTS

The figure is used to express power. Race wheels with aero benefits can save you watts by making you go faster for less effort.

YAW ANGLE

The direction the wind moves in relation to the direction the wheel moves.

TUBELESS-READY

Tubeless-ready wheels don't need inner tubes. They just need some sealant squirting inside before inflating. In the event of a puncture, you can always stick a standard tube in.

SPOKES

A number of rods are threaded from the hub to the rim to strengthen the wheel. Race wheels often have bladed spokes to reduce drag.

FULCRUM SPEED 55 DB

£1,899.99 The Speed 55 DB wheelset features Fulcrum's 2-Way Fit system which, according to Fulcrum, means they should run well as tubeless or with tubes thanks to extra precise engineering in the valve area. A 19mm internal width is bang on trend and an asymmetrical spoke pattern with 21 at the front and rear should improve balance and stiffness. On the road, the Speed 55S provides a very smooth ride, enhanced by USB ceramic bearings. The freehub whistles quietly, which is appropriate for the regal ride experience, and when you want to crank the power-up, engagement is rapid. They're no trouble at all in the wind, and we think the Speed 55 front wheel would be ideal paired with a rear disc wheel for very fast days. They're not cheap, but you're getting a super-refined ride feel for the premium. i-ride.co.uk

89% VERDICT A BIG INVESTMENT, YES...BUT WITH BIG PERFORMANCE TO MATCH