You come out of a tight corner and stamp on the pedals to close a gap. The bike jumps forward, and for a moment you feel whether the rear wheel stays with you or flexes sideways under the load. On another day the course turns onto an exposed stretch with a crosswind from the left, a gust hits the front wheel and the bars twitch. Those are two different jobs for two different wheels, and it is why the Avalon SL5 and the Avalon SL5 Ninefold do not use the same rim depth at both ends. It is what makes the SL5 a mixed depth wheelset.
The front wheel steers, the rear wheel drives
A deeper rim presents a larger side area to the wind. On the front wheel, that side force goes straight into your steering: a gust pushes the wheel, and you feel it in your hands. So the front wheel is where you want a profile that keeps the bike calm.
The rear wheel has a different job. Every watt you produce goes through it, and the air around it is already disturbed by your body and the bike, which means extra rim depth adds little aerodynamic gain there. What a deeper rim does add is stiffness: the rim itself contributes extra lateral rigidity when you accelerate and sprint, at the point where the wheel takes the most load.
Why a mixed depth wheelset: 50mm front and 55mm rear
The stagger is small: 5mm. The 50mm front rim is deep enough for an aerodynamic advantage at race speed, without letting a gust take over the steering. The 55mm rear rim adds that extra bit of lateral stiffness where the power goes in. The result is a wheelset that feels calm at the front and solid at the back.
Avalon SL5 Carbon Rim Profile
The rim is 23.5mm internal, hooked and tubeless ready, and it is rated for tires from 27 to 33mm. For the best aero shape, low rolling resistance and high grip, we recommend 28 to 30mm tires. Our Size & Pressure Chart shows the pressure to start from for your tire width and weight. The ART asymmetric rim design evens out spoke tension between the two sides of the rear wheel, so the wheel holds its shape under sprint loads instead of flexing energy away.
Two builds on the same rim
The Avalon SL5 uses 24 steel aero spokes and DT Swiss 240 hubs: fast, stiff and aero. The Avalon SL5 Ninefold is the top of the 9th Wave range, with carbon spokes (Alpina Carbolite) and our own Onda-R hubs with ceramic bearings, and it weighs 1134g for the set.
The Ninefold uses 20 spokes at the front and 20 at the rear, and that is not there to save weight. In our tests, a 24-spoke version turned out to be too stiff, and it gave up comfort for it. Carbon spokes already add stiffness compared with steel spokes, so adding more of them pushes the wheel beyond what you need on the road. With 20, the wheelset as a whole works better: stiff enough for a sprint or a fast corner, and calmer over long hours on rough tarmac. Building a carbon-spoked wheel with a free choice of spoke count depends on the hub: the Onda-R is our own design, which lets us set the flange diameter and the number and position of the spoke holes.
Who it is for
Both wheelsets are for riders who race and climb hard and want a fast, stiff aero wheel. The SL5 is the all-round race choice, and the Ninefold is the lightest aero option we build. Hand built in the Netherlands, and once you register, the carbon rims carry a lifetime warranty.
Frequently asked questions
What is a mixed depth wheelset?
A wheelset with a different rim depth at the front and the rear. On our Avalon SL5 and SL5 Ninefold the front rim is 50mm deep and the rear rim 55mm.
Why is the rear rim deeper than the front rim?
The front wheel steers, so a shallower rim catches less crosswind. The rear wheel drives, and extra depth there adds lateral stiffness under sprint and acceleration loads without affecting the steering.
Which tire size should I use on the Avalon SL5?
The rim is rated for 27 to 33mm tires. For the best mix of aerodynamics, rolling resistance and grip we recommend 28 to 30mm. The pressure chart gives the maximum pressure for your tire width, and the best pressure is usually lower than that maximum.
Why does the Avalon SL5 Ninefold have 20 spokes?
Carbon spokes are already stiffer than steel spokes. In our tests a 24-spoke version was too stiff and gave up comfort, so the Ninefold uses 20 carbon spokes at the front and at the rear.
View the Avalon SL5 or the Avalon SL5 Ninefold in our webshop.
