Five of the best gravel bikes from Unbound 2021

Bask in some wonderfully diverse tech from one of the biggest gravel events in the calendar

It feels like gravel racing is having a bit of a moment and the Garmin Unbound Gravel (formerly DK200) held in Kansas is one of the biggest events in the calendar.

Advertisement MPU article

Unbound 200 (it’s actually 206 miles long) gets most of the attention and attracts some of the biggest names in the sport, but there are longer and shorter events too, with the extreme 357-mile Unbound XL for true masochists.

Gravel is a fast-evolving discipline and it attracts a diversity of bike tech not seen in other categories. We’ve rounded up some of the coolest bikes from the 2021 event for you here.

Ian Boswell’s Specialized “Rock Combo” Diverge

We absolutely love this bike’s throwback paintjob.

Claimed to be a sort of OG gravel bike, the original 1989 Specialized Rock Combo was a close relative of the iconic Rockhopper mountain bike, but it had drop bars. This modern-day Specialized Diverge gravel bike pays tribute to the retro bike, but there’s nothing old-fashioned about it.

Specialized supplied three Unbound riders with Rock Combo Diverges and Ian Boswell won the 206-mile men’s race on this 58cm bike, completing the course in 10:17:24.

Original 1989 Specialized Rock Combo drop-bar MTB
Boswell’s Diverge is a tribute to the 1989 Rock Combo.

The Diverge is one of our favourite gravel bikes thanks to its well-judged geometry and Future Shock 2.0 system, which incorporates suspension into the upper part of the headset. If you want to know more about the specifics, don’t miss our detailed Specialized Diverge review.

Boswell’s build is based on a 1×12 SRAM eTap AXS wireless drivetrain in a ‘mullet’ configuration that mixes road and mountain bike parts.

A Force power meter crank with a 46t chainring is matched to a big 10-50t Eagle cassette, necessitating an XX1 mountain bike rear derailleur at the back.

SRAM eTap AXS mullet drivetrain
Boswell opted for a SRAM eTap AXS 1× mullet setup.

The wheels are gravel-friendly Roval Terra CLXs with 25mm-internal carbon rims that are a great match for chunky gravel tyres.

Boswell stuck with Specialized for his tyres and saddle too, choosing 42mm Pathfinder Pro rubber pumped up to a reasonably hard 40psi and the ever-popular S-Works Power seat.

Aside from the amazing paintjob, the most distinctive feature of this bike is its cockpit. The S-Works stem is long by gravel standards at 130mm – Specialized normally specs a 110mm on this size bike – and the bar itself is the extraordinary Coefficient Cycling RR.

Coefficient RR handlebar
The Coefficient RR bar is not quite like anything else.

This slightly wacky-looking carbon cockpit has radically swept aero-profile tops and an extra section in front of the stem that doubles as a computer mount and a mini aero bar.

Viewed from the front, the bar has a negative rise, helping a flexible rider like Boswell get lower than would be possible with a more standard setup. At 400mm wide, it’s definitely more road width than gravel.

Another slightly left-field choice is the Look X-Track Race Carbon Ti pedals, perhaps chosen to avoid sponsor conflicts. These are a fully SPD-compatible alternative to Shimano.

Lauren De Crescenzo’s Colnago G3X

Colnago G3-X with aero bars
The G3-X is arguably Colnago’s first proper gravel bike.
Cinch Elite

Rather than going on a regular honeymoon, Lauren De Crescenzo chose to ride Unbound 200 just days after getting married, and she won the women’s race with a finishing time of 12:06:49, riding for team Cinch Elite.

De Crescenzo’s Colnago G3X build looks a little more ultra-distance oriented than some, with a full-fledged clip-on Zipp aero bar offering her a properly fast position for long periods in the wind.

Clip-on aero bar
Like many racers, De Crescenzo chose to fit an aero bar.
Cinch Elite

Her coach Tom Danielson – a former pro himself – describes aero bars on a road or gravel bike as “a horrible experience” and notes that the “only way to ride well with them is you need to fit them on the bike, and in an optimal position for the rider, as well as spend the right amount of time doing focused training using them”.

The G3X strongly resembles Colnago’s V3Rs road bike, but the geometry and clearances are stretched for gravel.

De Crescenzo rides a 49s (49cm sloping) frame and it’s built up with a SRAM Force eTap AXS 2× drivetrain with 48/35 chainrings and a 10-33 cassette.

Muddy SRAM Force 2× power meter crank
While 1× is hugely popular in gravel racing, plenty of riders still favour a 2× drivetrain.
Cinch Elite

There doesn’t seem to be a right answer to the endless 2× vs. 1× debate for gravel bikes – both have their proponents and neither seems to offer a clear-cut advantage in real racing.

De Crescenzo’s bike is running Knight TLA 50 carbon wheels. By current gravel standards, these aren’t ultra-wide at 19.5mm internal, although it’s fair to say minor details like this weren’t holding her back on race day.

They are fitted with Maxxis Rambler 40mm tyres, a really popular choice for typical US racing gravel conditions that offers some bite in dirt without rolling too slowly.

Maxxis Rambler tyre on Knight carbon wheel
Maxxis Ramblers are a popular choice among Unbound riders.
Cinch Elite

There aren’t any super-niche components on this build, but personal touches include hair ties to help with bottle retention, and Silca Super Secret wax chain lube to minimise friction.

Jess Cerra’s Pinarello Grevil

Given we’re talking about a thoroughly American event, the prominence of Italian bikes might be a little surprising, but Pinarello had a fantastic Unbound too, with two of its sponsored riders, Amity Rockwell and Jess Cerra, coming second and tenth in the women’s 200 respectively.

Both were riding Pinarello Grevils, and we’re going to focus on Cerra’s eye-catching red bike.

Cerra rides a 50cm frame and her bike has a very similar SRAM 1× mullet setup to Boswell’s, albeit with a 42t chainring. Cerra prefers 1× for gravel saying: “I don’t want to deal with shifting in the front”.

SRAM 1× mullet drivetrain
This 1× SRAM mullet setup is very similar to Ian Boswell’s.

The Enve G23 carbon wheels are suitably gravel-specific and Cerra was running 42mm René Herse Hurricane Ridge tyres. These were both set at 28psi to help stop her “bouncing around” for 12 hours.

She says “hell no” to aero bars and opted for an Enve SES AR road cockpit at a modest 400mm wide. This has one key custom tweak in the form of Togs, small add-on thumb rests that fit on the drops for a little extra support.

Tog thumb rest on drop bar
Togs offer a handy extra thumb rest.

Like so many gravel racers, Cerra’s pedal of choice is Shimano’s XTR SPD, while her saddle is a similarly popular Specialized Power.

Colin Strickland’s Allied Echo

Colin Strickland racing Unbound 200
Colin Strickland was a key favourite coming into the race.
Ian Matteson

Colin Strickland, defending champion of Unbound 2019, rocked up in Kansas with two different bikes: the Allied Able and the newly-released Allied Echo.

This year, he finished Unbound 200 in fifth place aboard the Echo with a time of 10:25:34.

The Allied Echo aims to be a road bike one day and gravel race bike the next, thanks to rather neat flip-chips at both the fork and rear dropouts. These let you tweak geometry and have the side-effect of adding tyre clearance in their more gravelly configuration.

Aerodynamics play an important role in gravel racing and while the frame might not be as aero optimised as other gravel race bikes, it does feature a clever integrated cockpit made by Allied.

Colin Strickland and his Allied Echo
The Allied Echo is at the road-adjacent end of the gravel spectrum, and it features a very clean cockpit.

This creates a very clean front end with no cables in sight, and marginal gains can add up when you’re racing at such a high level on a really long course.

Unbound is known for its savage headwinds, so one can only imagine looking down at a clean cockpit will help give a mental boost when things get really tough.

You’ll notice the race-day bike has a custom frame bag attached to the top tube. This was actually crafted by Strickland himself the night before the event, and he explains on his Instagram exactly how he made it.

DIY frame bag on Allied Echo
Strickland made this unique frame bag for race day.
Ian Matteson

Strickland didn’t do this just for the cool gravel aesthetic – its main function was to house a two-litre water bladder for hydration over the 200 miles. He claims this also helps improve aerodynamics and relieves lower back pain compared to wearing a hydration backpack.

Strickland’s bike is built up with a 2× Shimano Di2 drivetrain that mixes GRX gravel components (shifters and rear derailleur) with road parts (cassette, front derailleur, crank) and Enve carbon wheels.

Strickland racing his Allied Echo
Strickland’s drivetrain mixes Shimano Dura-Ace and GRX gravel components.
Ian Matteson

With fast-rolling Specialized Pathfinder Pro tyres, Strickland’s Allied is one of the more road-adjacent builds we’ve seen, although he too was running clip-on aero bars on the day.

Lael Wilcox’s Specialized Epic

Lael Wilcox with her drop bar Specialized Epic
Lael Wilcox rode a rather special drop-bar Specialized Epic.
Rugile Kaladyte

Racing 200 miles is very impressive and all, but Unbound XL takes things up a level. Lael Wilcox won the women’s race with a time of 26:55:24 (more than a solid day of racing).

Wilcox rode the event on a custom-painted Specialized Epic hardtail she first built up for the 2019 Tour Divide. Yes, she won this “gravel” event on a mountain bike, albeit one fitted with drop bars.

Lael Wilcox fiddling with her bike
This build had already proven itself at other ultra-distance events.
Rugile Kaladyte

While she also regularly rides a Specialized Diverge, Wilcox opted for a mountain bike to cope with prolonged riding on rough terrain, with the suspension, larger volume tyres and more upright riding position all helping to keep the pain levels manageable.

Lael Wilcox riding Unbound XL 2021
Wilcox’s setup for the XL is more geared to comfort than the Unbound 200 bikes we’ve featured.
Rugile Kaladyte

Afterwards, she said it: “definitely the right tool for the job”, and you can hardly argue given the result.

Wilcox’s Epic build sports a RockShox SID Ultimate fork and yet another SRAM Eagle AXS wireless 1× drivetrain, with a 36t chainring and 10-50 cassette.

Her wheels are built up with Roval SL carbon rims and it’s notable that the front is laced to a Son dynamo hub, a favourite component of serious long-distance riders who need lighting that can’t run out of batteries.

Lael Wilcox riding Unbound XL 2021
When is a gravel bike also a mountain bike?
Rugile Kaladyte

As this is a mountain bike, it’s not surprising to see fatter rubber – the Epic is wearing a 700×55 René Herse Fleecer Ridge tyres, while the rear is a 700×48 Oracle Ridge from the same brand, both with the Endurance casing that adds reinforced sidewalls.

Wilcox actually had a hand in developing these tyres and both feature “noise cancelling” where “staggered tread blocks create overlapping noise frequencies that partially cancel each other”. For real.

Gravel is a joy for bike tech nerds

One of the great joys of gravel is seeing the different approaches riders take to these events.

It’s a fast-evolving discipline where the rules and conventions haven’t really settled down, so there’s still plenty of room for riders to get creative with their setups.

Advertisement MPU article

How would you spec your bike for 200 (or more) miles of gravel? Let us know in the comments.