Fulcrum Sharq GR and Sonic GR: Gravel Wheels Optimized for 47–50mm Tires

Fulcrum just released two gravel wheelsets with a 30mm internal rim width—5mm wider than what they launched earlier this year. The Sharq GR and Sonic GR are both designed around 47–50mm tires, not the usual "fits everything from 40 to 55mm" compromise most brands settle for. If you're running big rubber and staying there, this is the first wheelset I've seen that actually optimizes for that width instead of hedging.

The rims use a variable-depth wave profile (47/52mm) that Fulcrum claims cuts drag by 29% at wind angles between 10º and 20º. More importantly, they say it improves "yaw moment"—basically, crosswind stability. I can't verify the drag number without a wind tunnel, but the mechanism makes sense: the wave disrupts airflow separation. Here's the catch: aero gains at gravel speeds (15–20 mph) are marginal. You're looking at maybe 5–10 watts saved in ideal conditions. If you're racing or doing long solo efforts, that adds up. If you're riding with friends on dirt roads, it won't.

The Sharq GR is the lighter option at 1,550g with aero spokes and a stiffer carbon layup (FF100 vs. FF80). It uses cup-and-cone bearings, which are smoother but require occasional adjustment—something I'd rather not think about as a dad with limited wrench time. The Sonic GR is 145g heavier, uses sealed cartridge bearings (set-and-forget), and costs €500 less. For most riders, the Sonic makes more sense unless you're chasing grams or racing.

One detail I like: the spokes don't touch where they cross. Fulcrum says this lets each spoke flex independently, which should improve compliance over rough terrain. The rims are also hookless with a "mini-hook" for bead retention, so you get a wider range of safe tire pressures without needing rim tape. Both are non-drilled, which simplifies tubeless setup.

The real question is whether you're committed to 47–50mm tires. If you swap between 40mm and 50mm depending on the ride, these wheels won't work well at the extremes. Fulcrum says some 45mm tires fit, but they won't validate that because it falls outside ISO standards. If you're all-in on wide tires and want the aero benefit without the "fits everything" penalty, these are worth considering. If not, you're paying for specialization you won't use.