Sonder is the in-house bike brand of Alpkit, the British outdoor retailer based near Nottingham and the Peak District. Launched in the mid-2010s, it designs mountain, gravel and adventure bikes built to order, with signature models including the Frontier hardtail and the Camino gravel bike.

Sonder uses a direct-to-consumer, value-focused model, selling online and through Alpkit's UK stores rather than a traditional dealer network, with customisation and try-before-you-buy options. Parent company Alpkit is a certified B Corp.