What is a Gravel Bike + What Makes it Different from Other Bikes?
There are many different bikes to choose from these days. As manufacturers have expanded their line ups to meet the needs of cyclists and their preferred riding style, the new cyclist has been presented with a great bicycle for every situation. However, the increased number of choices sometimes leads to confusion. Here are some reasons why we think gravel bikes actually simplify this choice by being the best all around bike and how they stack up against other categories.
What is a gravel bike?
Let’s start with defining what a gravel bike is. When someone mentions a gravel bike, they are usually referring to a drop bar bicycle with wide tire clearance. This is a super versatile combination. The drop bars create efficiency by allowing a more aerodynamic position. They also allow for multiple hand positions for all day comfort. The wide tire clearance means more options in the terrain you ride and increases comfort over rough terrain by running lower tire pressure. While wider tires are slightly slower on tarmac (not much) they open up the possibility of riding on gravel, sand, mud, and even light mountain bike trails all on the same bike.
What are the benefits of a gravel bike?
We view the primary benefit of a gravel bike as being its versatility. Gravel bikes like the Diamondback HAANJO 4 or the Niner RLT 9 have a geometry that makes them comfortable for all day rides, stable in rough conditions, and efficient enough for the road. A bike like the Marin Gestalt X11 is designed to be an all road option, designed for gravel, road, and everything in between by just swapping the tires to best suit the primary surface. Gravel bikes offer both a rider position that is more friendly to those not looking for an aggressive position and the gearing needed to climb steep grades with ease. This makes gravel bikes ideal for the new cyclist who wants to dip their toes into multiple segments of our sport.
Unique Features of Gravel Bikes
Tires
Gravel bikes have many unique features. As previously mentioned, they allow for increased tire size. You can still run a road tire if you’d like, but most modern day gravel bikes will allow for up to a 700x47c or 650x2.1” tire. These tires can be smooth and treadless, have an aggressive tread pattern, or anywhere in between depending on the terrain you ride. The Panaracer GravelKing SK is a great all around tire for gravel and we’ve also had great luck with Pirelli’s complete line of Cinturato tires with the Pirelli Cinturato M for mixed surfaces and Pirelli Cinturato H for more hard surface riding. Most gravel wheel/tire combinations are also designed to be run tubeless. A tubeless gravel setup will usually allow you to run 40 psi or less. Lower pressure means more comfort on rough terrain and more traction in slick or loose conditions – equalling more confidence and fun for the rider. The sealant added to these tires also means less time fixing flats from thorns and sharp rocks, and since there is no tube, you don’t have to worry about pinch flats!
Frame
Gravel frames are made of a variety of materials. Just as in road, carbon frames are light and allow the use of unique tube shapes to increase tire clearance, aerodynamics, and tune the ride quality. Aluminum gravel frames are also a good choice for the budget conscious. In fact, we’d argue that aluminum competes well with carbon in this segment because much of the comfort loss in aluminum is made up by the wide tires absorbing the harshness you may experience on a bike with skinny tires. As with other genres of bicycles, there are also boutique steel and titanium frames to choose from that offer a unique blend of strength, weight, and ride quality.
Gearing
Gearing is one of the major differences between gravel and other genres. The key here is having a wide selection of gears. You want to be ticking away the miles on asphalt one minute before jumping on to your favorite dirt climb the next. Component manufacturers achieve this in different ways. 1x setups with wide range cassettes are great for gravel because of the simplicity. The options are endless, but usually these bikes will have something like a 40t chainring paired to a wide cassette – think 10/42 or even more. SRAM is known for defining the 1x drivetrain and has perfected their system with 11 and 12 speed variations. If you want even more range, a 2x setup is a great option. Shimano’s gravel specific GRX line often comes with a 48/31 chainring combo. This allows for both efficiency and high speed on the road and the ability to climb just about anything you’re willing to try. These bikes are usually spec’d with a closer ratio cassette such as an 11-36 for smaller jumps in the gearing while still having plenty for climbing.
Brakes
With increased tire size and riding on more varied terrain, stopping power becomes a high priority. Essentially all modern gravel bikes will be equipped with disc brakes. Entry level bikes will usually come spec’d with cable-actuated discs that still provide good stopping power but lack some of the power and modulation of a more premium hydraulic brake. Once you enter the mid-range category, bikes will be equipped with hydraulic disc brakes. These provide excellent stopping power allowing for one or two finger braking while also allowing more finesse. This is great for maintaining traction while also having the ability to slow down quickly when needed. Typically 160mm rotors are the standard, but some more aggressive setups will come with a 180mm rotor up front.
Geometry
The frame geometry of gravel bikes varies widely. Generally you can expect a gravel frame to have a longer wheelbase, slacker head tube angle, and lower bottom bracket for maximum stability. The top tube of gravel bikes has gradually been extended for stability and stem length has gotten correspondingly shorter.
Tube shapes have been modified to increase comfort. Many brands have added their own take on increasing compliance through thinner tubes, pivots, and other ways of adding small amounts of frame flex in just the right areas. Seatposts have also been modified to further increase bump and vibration absorption.
Other frame differences include an increased number of mounting points for bags, extra bottles, and racks.
Gravel Bikes vs. Mountain Bikes: What’s the difference?
The obvious difference between gravel and mountain bikes are the drop handlebars on most gravel bikes. The flat bar on mountain bikes is primarily all about maximizing control. Control is a great thing, but there are some downsides to the flat bar. Flat bars are less aerodynamic and they can also lead to more shoulder and hand discomfort over longer distances. As they bring their elbows out, cyclists also tend to squeeze their shoulder blades slightly and carry more tension in their shoulders. While a proper bike fit can alleviate this, flat bars usually don’t match the comfort of a drop handlebar. Drop bars simply allow for a more natural position for long days in the saddle. You can think of it as taking your hands resting by your side and bringing them up to “shake hands” with the handlebars. Your shoulders should not feel an increase in tension.
Drop handlebars also have more hand positions you can adopt on the bike. General riding – ride on the hoods, descending and looking for maximum control – in the drops, and cruising, sitting up and talking to friends, etc. – you can ride on the tops of the bars. Having three spots to place your hands also allows you to change position to be more comfortable on long rides.
Another difference is USUALLY the lack of suspension. Most mountain bikes have suspension while gravel bikes do not. This is changing though! Many brands now make a gravel bike with a small amount of travel in the front and even sometimes the rear. The amount of travel is never equal to the much longer travel found in a mountain bike. 20-50mm, if any at all, is the norm on gravel while mountain bikes are always at least 100mm.
Tire width is the other big difference. While something like a 47c or a 2.1” tire is large on the road, this is still smaller than most mountain bikes which are likely 2.3” or more, with many tires sitting around 2.4-2.6” on most mountain bikes. The smaller tire of the gravel bike means more efficiency in most terrain.
How is a gravel bike different from a road bike?
Gravel and road bikes have a lot of similarities, but there are key differences. Gravel bikes will have the previously mentioned longer wheelbase, lower bottom bracket, and slacker angles to increase stability on rough terrain and steep descents. They also have much more tire clearance. Gravel bikes will also have gearing designed to cover more terrain. While they may lack some top end speed, they will have gearing that enables you to get up more steep and challenging climbs.
Another difference is the rider position. Gravel bikes are normally set up to allow the rider to take on a more upright position. They will have shorter stems and taller head tubes to bring the handlebars both up and closer to the rider. Gravel bikes also tend to have their own style of handlebar that is both wider and flares in the drops which is great for further increasing stability and control.
What’s the difference between a gravel bike and a cyclocross bike?
Although gravel bikes and cyclocross bikes look similar, and cyclocross bikes can absolutely do double duty between the race course tape and on gravel roads, the ride feel is very different. Traditionally, cyclocross bikes have steep angles and a tall bottom bracket to allow cornering on a dime without striking the inside pedal through corners. Cyclocross bikes will generally feel taller and more twitchy than a gravel bike. Also, many cyclocross bikes do not have the increased tire clearance of a gravel frame. If you don’t plan on bombing down too many steep hills you may not notice much, but a gravel bike will feel much more stable when the speeds increase and things get rough.
The popularity of gravel has exploded in recent years, so some brands are now dropping the bottom bracket and making their cyclocross bikes just a little less twitchy while increasing tire clearance in search for that sweet spot where the bike is nimble on the cx course while also being stable on faster and looser terrain.
We love riding gravel and it’s a great way to not just explore new terrain but also do something a little different. See some of the great options for gravel bikes here and talk to our staff about their experiences exploring new roads!
Leave a comment