Zipp has announced its newest road wheelset and it’s significantly more affordable than the brand’s top-end offerings.
The 303 S is a 45mm deep, tubeless-only, disc-only carbon clincher that will retail at £985 / $1,300 / €1,100, slightly less than the previous generation 302 Carbon Clincher Disc Brake.
This price tag puts the 303 S in competition with wheels from makers such as Flo, Prime and Hunt.
Wider and faster than the 302, and tubeless only
Weighing a claimed 1,540g for the set, the 303 S is optimised for 28mm tyres and can accommodate rubber up to 50mm wide, suggesting it’s targeted particularly at endurance road and gravel bikes.
Compared to the old 302, the 303 S is 2mm wider externally at a maximum 27mm, while internally it’s 7mm wider at 23mm, making it better suited to wider tyres. The rims are hookless to “create a seamless transition” to the tyre.
This is an important detail because it means the rims are only designed to be used with tubeless or 'tubeless-ready' tyres.
According to Zipp, you can fit a tube in your tubeless tyre as a get-you-home measure in the event of a puncture, but you must only use tubeless tyres because the tyre "must have the stiffer tubeless specific bead" to be safe.
Also important to note is that the maximum allowed pressure for these rims is 72.5psi (5 bar), which is pretty low for a road wheelset.
If you're running tyres no smaller than 28mm, 72.5psi will likely be enough for you, but it's very important to adhere to the stated limit as exceeding it risks provoking a blowout.
Zipp claims its new rims improve tyre profile (with a 28mm) and allow lower pressures, saving 10 watts at 40kph vs. “a top peer wheel” which, it turns out, refers to the current generation 303 Firecrest.
The 303 Ss are built on Zipp’s own 76 and 176 DB hubs with 24 conventional J-bend spokes front and rear, a spec choice that should make sourcing spares straightforward.
Despite the reasonably low total weight, brass nipples are used, a bonus for all-weather durability.
It appears Zipp is making a conscious effort to distinguish its new wheels from the existing flagship NSW and Firecrest options.
The logos are more restrained, a clear departure from the familiar design that’s dominated by the ‘speedy Zipp’ (I just coined that) typeface.
The 303 S is expected to be available this month, and Zipp has hinted at more new wheels in the pipeline.
