45, 50 or 58 mm: how to choose carbon wheel rim depth
If you are not sure, buy 50 mm. It is quick on the flat, calm enough in a crosswind that you stop thinking about it, and it is the depth that suits a rider who does a bit of everything. The other two depths exist because "a bit of everything" is not what everyone does.
Here is what the choice actually costs, taken from the MY2026 figures for the two families that carry no rider weight limit:
| Depth | C series (steel spokes) | S series (carbon spokes) |
|---|---|---|
| 45 mm | 1290 g | 1190 g |
| 50 mm | 1320 g | 1220 g |
| 58 / 58.5 mm | 1420 g | 1320 g |
Read down a column rather than across it. Within a family, going from 45 to the deepest option costs about 130 grams — roughly a full bidon of water that you carry on every ride, for an aerodynamic gain you only collect above about 30 km/h.
When 45 mm is the right answer
Go shallower if your riding climbs, if you are light, or if you ride somewhere genuinely exposed.
The weight argument is the obvious one and the weakest. A hundred grams is not going to decide a climb. The real argument is handling: a shallower rim presents less surface to a side wind, so a gust moves the front wheel less, and you spend less of the descent bracing against something that has not happened yet. If you have ever come off a bridge deck or out of a gap in the trees and felt the bar step sideways, you already know what this is worth.
It matters more the lighter you are. A 60 kg rider and an 85 kg rider are hit by the same gust, and only one of them has the mass to ignore it.
When 58 mm is the right answer
Go deeper for flat, fast riding: time trials, triathlon, criteriums, long days on open road where you hold a speed rather than change it.
The gain is real and it grows with the square of your speed, which is why it is worth almost nothing on a 25 km/h club ride and worth a measurable amount on a 40 km/h effort. That is the honest way to frame it — not "faster", but "faster at the speeds where drag is most of what you are fighting".
You pay for it in two places: the weight in the table, and a wheel that a crosswind can lean on. Neither is a problem on the right day. Both are a nuisance on the wrong one.
What does not change with depth
Across every depth we sell, the rim is 24 mm internal and 31.5 mm external. That is a modern, wide profile: it suits 28 mm tyres and up, and it holds a 28 mm casing out closer to 30 mm in practice, which is most of where ride quality comes from.
Hub, spoke pattern, freehub choice and warranty are also identical across the three depths in a family. You are choosing one variable, not three.
Depth is not the biggest lever
It is worth saying plainly: for most riders, tyre choice and tyre pressure change how a bike feels more than 13 millimetres of rim depth does. If you are deciding between a deeper wheel and a better tyre, buy the tyre.
Where depth does earn its place is at the top of the speed range, and in how the bike behaves when the wind is across you. Those are the two questions worth asking yourself before you pick.
Still deciding?
The comparison table puts every family side by side — spokes, hubs, weights and rider weight limits — and the wheelsets page lets you filter by depth directly.
Or just ask us. Tell us the bike, the roads you ride and what you are trying to fix, and we will tell you which one to get — in English or French.
The other two questions
Depth is one of three things that decide which wheel you end up with. The other two can rule an option out before depth ever matters: whether a rider weight limit applies to you, and which freehub your bike takes. Both are a two-minute read.
Two more guides cover what the depth does not: carbon spokes or steel, and tubeless or tubes once the wheel is chosen.