Rims

The 41mm, full carbon rim is the most striking feature of the Assault SLG Disc. The Swirl Lip Generator – a groove cut either side of the spoke bed, intended to smooth airflow and allow it to reunite more quickly at the rim’s trailing edge to defeat drag – that we’ve previously encountered on Reynolds more upscale hoops (the R32, for example) is present and correct, but notably absent (by design, rather than accident) is a brake track.

Full carbon rims are nothing new, of course, but their wider uptake has been affected by tales of overheating after prolonged braking on mountainous descents. The removal of the rim from the stopping mechanism has been trumpeted as one of the key advantages of disc brakes and Reynolds have not shied away from advertising the fact with graphics that stretch almost to the edge of the rim.

More significant, perhaps, is Reynolds’ reversion to the use of external spoke nipples, used in tandem with continued deployment of the rounded rim profile now replaced on their upscale hoops. Reynolds claim the combination of the two allows the use of maintenance-friendly spoke arrangement with no loss of aero performance. We can add that while the spoke nipple is still partially concealed, it is sufficiently exposed to attach a spoke key.

Our final observation concerns the rim width. The Assault SLG Disc offers an external rim measurement of 25mm and an internal measurement of 17mm, placing it squarely in the ‘wider is better’ vanguard: a belief that stems from the claimed benefits to aerodynamics, comfort, and free-rolling said to accrue from a smooth interface between rims of this type and tyres wider than the roadie’s traditional preference for 23c. We’re still deciding which tyre to try with our sample set, but we’ll be hoping to test some of the aforementioned claims by reaching for rubber in a 25c profile or wider.