Hit a rutted gravel descent and pay attention to where the impact actually lands. The front wheel tracks the line and takes its share of hits, but the rear wheel is carrying your body weight, your gear, and every watt you put through the pedals, all while taking the same rocks and washboard as the front. It doesn’t get built the same way for a reason, and nowhere is that clearer than with carbon spokes on a gravel wheel.
On the SandStone SL Ninefold, that reason is carbon spokes, and how they’re used front and rear.
Why carbon spokes on a gravel wheel in the first place
The standard SandStone SL builds on Alpina Ultralite aluminium spokes — a proven, reliable choice. The SL Ninefold moves to Alpina Carbolite carbon spokes instead. Spoke for spoke, carbon can carry the same load at a lower weight than aluminium, which is what lets the SL Ninefold drop to 1225g without narrowing the rim or cutting corners elsewhere. That weight saving is the real upgrade here, not a change in how the wheel behaves, just less of it to carry uphill.
Gravel adds a layer road riding doesn’t have: sustained impacts from a surface that’s never flat. A carbon spoke has less give than aluminium under a sudden shock load, so simply going full carbon and keeping a low spoke count everywhere would put more stress through fewer spokes on exactly the wheel that’s already absorbing the most abuse. That’s the trade-off the spoke count is built around.
Carbon spokes also need a hub designed around them. Flange diameter and bracing angle matter more with carbon than with aluminium, which is why the SL Ninefold runs 9th Wave’s own Onda-G hub rather than a modified version of an existing platform — the geometry is built for this spoke material from the start, not adapted to fit it.
Why the rear wheel gets four more spokes
The SL Ninefold uses 24 spokes at the rear and 20 up front. That’s not a novelty, it reflects where the load actually goes. The rear wheel carries most of your body weight, transmits every watt of drivetrain torque, and takes the brunt of impacts from rocks, ruts and washboard while it’s doing both. Keeping 24 spokes at the rear, the same count as the standard SL, gives it the stiffness and durability margin gravel racing demands.
The front wheel has an easier job. It handles braking and steering loads, but it isn’t carrying drivetrain torque or the bulk of your body weight, so it can safely drop to 20 spokes without giving up anything in reliability. That’s four fewer carbon spokes’ worth of weight at the front of the wheel, exactly where it matters most for how the bike accelerates and changes direction.
The alternative approaches both have an obvious downside. Running 24 carbon spokes front and rear would erase most of the weight advantage over the standard SL. Running 20 at both ends would save a bit more weight, but it would put that lighter spoke count on the wheel carrying the most load and the most impact, exactly where you don’t want to cut margin on a wheel built for racing. Twenty front, twenty-four rear is the allocation that gives up nothing where it counts.
What that means on the bike
The result is a wheelset that’s lighter than the standard SandStone SL by more than 150 grams, without giving up the 37mm internal width and 40–66mm tire range that defines the ART rim profile across the whole SandStone line. You’re not trading tire support for weight, and you’re not trading rear-wheel durability for front-wheel weight savings — the carbon spoke build and the 20/24 split are how both are possible at the same time.
For a rider who wants the lightest wheel in the SandStone range and isn’t willing to accept a narrower rim to get there, that combination is the point of the SL Ninefold.
Is it the right wheel for you?
If every gram matters for your racing but you still want a rim built for gravel, not a repurposed road rim, the SL Ninefold is built around that. If you don’t need the absolute lowest weight, the standard SandStone SL shares the same rim profile and tire range with aluminium spokes.
View the SandStone SL Ninefold in our webshop.
