The Billy Bilsland Cycles Verdict: The Topstone 4 is the perfect bike for adventurers, with a sturdy but lightweight design that gives all the control and versatility that you need.The Topstone is an amazingly capable, versatile gravel bike. Built for chasing horizons, exploring routes less travelled or accelerating your commute to work. Straightforward, reliable and a whole hell of a lotta fun, the Topstone Alloy is a gravel bike crafted for those with a taste of adventure. Roll light and free, or load it up for those long-haul trips. Where the Topstone thrives, is in its adventures. Pack for lunch or pack for the weekend, with mounts for three water bottles, top tube storage and fork mounts - plus sturdy rack mounts, this bike is ready to go.