When is a gravel bike, not a gravel bike? When it's also a mountain bike. Or at least, a gravel bike with MTB DNA, like the Baum DBM, a new chassis from the famed Australian builder that embraces all that mountain bikes have to offer, including 29 x 2.20–2.40" tire compliance, lower gear ratios, and a dropper post.
As with all Baum models, the DBM came to fruition because Darren Baum wanted to tackle a certain type of terrain. "I normally ride in the Brisbane Ranges along McLean's highway," he said on the release of the DBM. "Whoever McLean was, he didn't know what a highway was. It's got 20% pinches in it. I've wanted a bike to handle that kind of ride for a long time."
To create the DBM, Baum effectively grafted the rear end of an XC bike to an otherwise devoted gravel bike, then adjusted the handling to suit the larger tires. That's the easy way to explain the DBM. But as with all things Baum, the magic is in the geometry, fine details, exquisite workmanship and peerless handling tuned to the model's terrain du jour. For the DBM, that's steep climbs, fast and sinewy, root-laden singletrack, deep loam and largely unpredictable terrain demanding larger tires.
Darren says that race-oriented XC tires with a low-profile tread work well as a "plus-size" gravel tire. Thus, the DBM has enough clearance for 29 x 2.25" tyres with standard rear spacing (142 x 12 mm) or 29 x 2.40" tyres with boost spacing (148 x 12 mm).
The DBM's T47 bottom bracket shell, 3D-printed yoke, chainstays, and chainline are wider than the Orbis X, Baum's other gravel-forward model. More crank arm clearance is also needed, so the DBM requires an MTB crank (1x only, 44T maximum chainring size). One final touch for the rear end is UDH compatibility, which means the DBM is ready for SRAM's new generation T-type and Full Mount derailleurs.
Lest confusion arise over the DBM's melding of cycling styles, let's make one thing clear: the DBM's riding position is road-orientated. Its design is well-suited to long distances and a natural bikepacking companion eager and able to traverse the very worst terrain. To speak to the details, the DBM has more bottom bracket drop (~80 mm) than an MTB because there is not the same need for obstacle clearance. The head angle is nowhere near as slack as a modern MTB, either, but there is a longer top tube, shorter stem, and wider handlebars to compensate for the extra front tyre grip.
In classic Baum fashion, the specifications around fork choice, mounting points, integrated hydro routing, and so on are left for the customer to decide. So, if you're not interested in a rigid fork, then Baum can build the DBM to suit Lauf's Grit fork or even a 100 mm XC suspension fork. The same goes for racks, lunch boxes, bidons, and frame bags.
