The Castelli Undersaddle XL is the larger of the two Castelli saddle bags in the Italian brand's Race Bags collection. On off-season or longer length rides, extra saddle bag space can be welcome; the XL comfortably takes more than one spare tube, a multitool, tyre levers, Co2 canisters and inflators, patches, cable ties - the list goes on. An elasticised rear mesh mini pump sleeve works to further free up valuable space in jersey pockets.
The bag itself is made using tough, weatherproof material with a covered water-resistant zip to keep road spray and muck away from tools and tubes. Attachment straps at both the top and back of the saddlebag keep everything tightly in place as rough winter roads rattle you along.