38mm is the easy first upgrade
A 38mm rim usually feels balanced for mixed riding. It adds carbon depth without pushing handling too far for windy or rolling routes.
For older rim brake bikes, a moderate rim can be the cleaner first move because it keeps the bike useful in more conditions.
50mm gives a stronger road look
A 50mm rim has a deeper profile and a more obvious carbon-wheel appearance. It can suit flatter roads and riders who are comfortable with a bit more side area.
Check brake caliper and frame clearance just as carefully as you would with any other depth.
Very deep rims are a specific choice
An 88mm-style rim can look dramatic, but it is not the default choice for everyday riding. Wind, route, rider confidence, and braking setup matter.
If you are unsure, choose a moderate depth or contact support before ordering.