What is a gravel, or all-road bike anyway?
We tend to use "gravel bike" and "all-road" interchangeably to describe the bikes we ride in gravel, but find the latter a better fit, capturing the idea that a properly designed bicycle can be used on any kind of road efficiently and comfortably. Let's start by saying there are no hard and fast requirements that define what an all-road bike is or isn't. In the Venn diagram of bicycle types there is a good deal of comonality in the over lapping circles defining road bikes, cross bikes, mountain bikes and gravel bikes. As a result, it might be helpful to think about these bikes in terms of desirable characteristics rather than requirements.
In the short list of things that make a good all-road worthy bike perhaps the most important is tire clearance - how wide a tire you can fit in the frame and fork. Typical road bikes, designed to be aerodynamic, will fit only very narrow tires in their sleek frames. For gravel, we want something that will hold between 34 mm and 48 mm.
Rim brakes can also be a limiting factor in how large a tire will fit. Cantilever brakes, or disc brakes tend to be common in the gravel world because they never interfere with tire width.
Frame geometry is another important consideration because of its effect on handling and rider comfort. A frame with longer wheelbase, relaxed frame angles, and lower bottom bracket height will provide both stability and a more comfortable ride. Taller head tubes provide a more upright riding position for additional comfort.
Since gravel roads will likely take you into more challenging terrain than paved roads, lower gearing than typical on road and cycle-cross bikes helps the experience. One option that has emerged recently is what's known as the "one by", or 1X, a single chainring paired with a very wide range 11 or 12 speed cassette. This arrangement can get you the same range of gears as double chainring systems, leaving out some of the smaller steps between the extremes.
As with any bike genre, your choice of an all-road bike really depends on how you intend to use it. Gravel racers who compete in long endurance event generally ride drop-bar bikes with things like multiple water bottle mounts, or top tube tank bag mounts, or perhaps even some passive suspension like the Lauf fork. If bike packing, which is basic cycle-touring in the unpaved world, is the intent, you many choose a flat-bar rig with extra-wide tire clearance and rack and fender mounts.
Where do you want your all-road bike to take you?
Next time we will look at gravel events, the grass roots racing scene that has grown up in recent years.
At FBC the owner and staff have a passion for cycling – we all ride to help you ride better. Come and see us in Freeport at 120 South Chicago in Freeport to find out how we can help you get full enjoyment out of your cycling experience.