We learned a lot of lessons from this year’s bike test. One of our key takeaways is that gravel is no longer a niche category within the road-bike market; instead, it’s driving all drop-bar bike development.
Here are three elements that are shaping the future of gravel bikes.
Tire Clearance Is Everything
The leading bikes in this year’s test stood out for their impressive tire clearance. If a brand’s gravel bike couldn’t fit 700-by-50-millimeter tires, it fell off the back of the pack.
Widths of 48 to 50 millimeters are the new normal for the category. Companies like Maxxis and WTB are leading the charge with fast-rolling, high-volume tires that really take the edge off rocky roads.
To be sure, not every gravel ride warrants that much rubber. This style of riding encompases everything from hard-packed dirt roads that are as smooth as asphalt, to chunky gravel, and even singletrack. In keeping with the versatility of the breed, the ability to adjust to different types of terrain is a must.
That same frame and fork clearance is almost as important for clearing mud as it is about fitting wide tires. Events such as the Mid South, with its gummy red-clay roads, are case studies in the importance of tire clearance when dirt gets wet and starts sticking.
Single-Ring Drivetrains Are Not the Answer—Yet
As gravel tires grow wider, the amount of space between the front derailleur and rear tire has shrunk. One way bike designers addressed this lack of real estate was by getting rid of front derailleurs altogether. After all, it worked for mountain bikes, so why not gravel?
Many of our test bikes featured single-chainring drivetrains. Two of them, the Open WIDE and Allied Able, were dedicated single-ring frames. Overall, our test team wasn’t impressed with the limitations of even the widest of these options available.
Gravel cycling is not mountain biking. Our testers noted that the average tempo of a gravel ride is much broader than most mountain-bike rides, so having narrower steps between gears is very important for maintaining a consistent cadence, especially on endurance rides. So far, neither Shimano nor SRAM has managed to combine small steps between gears in a wide range on a single-ring drivetrain. It will take more cogs on the cassette before that happens, and our testers are in no rush to get there.
That said, both Shimano and SRAM are aware of the limitations of single-ring drivetrains for gravel. For 2020, both developed purpose-built two-ring gravel groups that push the front derailleur and chainrings out to gain chain clearance.
We’re not saying a single-ring drivetrain is the wrong choice for every gravel ride, rather that those built with two chainrings are still the safest bet if you’re not sure where the road will take you.
Suspension Is the Future of Gravel
Suspension and/or engineered flex systems were present on many of the gravel bikes this year. Why is suspension becoming such an important piece of the puzzle, you ask?
As someone who has finished five Dirty Kanza 200’s, I feel confident stating that comfort equals speed. Hands, shoulders, and your back all start to ache as the hours tick by. Technologies that mitigate any high-speed vibrations will keep you feeling fresher longer. Even if you’re not planning on pinning on a number plate, the additional cushion provided by these systems can make your ride more enjoyable while still giving you the benefits of a drop-bar bike.
Gravel suspension runs the gamut, from flex systems like those found on Trek’s Checkpoint and BMC’s URS, which bow to absorb road chatter, to actual full-suspension drop-bar bikes, such as Niner’s MCR 9 RDO.
Sitting somewhere between these extremes is the latest generation of Specialized’s Diverge, with an updated Future Shock 2.0 front end. It features 20 millimeters of suspension travel under the stem, providing a floating sensation over even the roughest gravel roads.