Test Rose Backroad AXS Mullet Build: A special feature among the Backroad models is the “Mullet” with 650B wheelset and mountain bike cassette. Does this make the carbon gravel bike even more off-road capable?
Rose offers the carbon backroad in eleven equipment variants; There are also three Limited models, ten aluminum backroads and E-Graveller. You first have to find your way around, and it's worth taking a close look at the specifications of the individual versions. Rose has quite unusual models in its range that are tailored to specific areas of use - such as the Backroad AXS Mullet Build, which is one of the few series gravel bikes with a 650B wheelset.
Rose Backroad AXS – Small wheels with advantages on a gravel bike?
650B = 27,5 inches is now a common wheel size on mountain bikes. The classic 26-wheels are potentially lighter and improve maneuverability, but larger wheels - the so-called "Twentyniners", i.e. 28-inch rims with wide tires - roll more dynamically over obstacles. However, 29-inch bikes are less agile. Here the 27,5-inch wheel has established itself as an intermediate size: even with large tires, such wheels allow for easy steering and a compact frame shape.
Gravel bikes usually use 622 mm wheels, i.e. 28 inches. Anyone who rides with 40 mm or 45 mm wide tires will get along well with them. However, if wider tires are required, for example because the bike is to be used in difficult terrain, problems can arise: the tires usually do not fit into the frame and fork, or only fit very narrowly, and the steering properties also change. The larger rolling circumference of the tires also makes the gear ratio longer - all gears are then slightly heavier.
Even more agile handling with 650B
This is where the Rose's 650B wheelset comes into play: its 47 mm wide tires are even slightly below the 622-40s in terms of rolling circumference, with the smaller radius ensuring more agile handling thanks to minimal geometry changes. At the same time, the wider tires can be driven with low pressure, which improves traction and of course ensures more driving comfort.
Will the calculation work? In any case, the Backroad Mullet Build immediately stands out because of its great handling. It is manoeuvrable and agile, can be accelerated at lightning speed and controlled with a light hand. However, that's no wonder given the steering angle is almost 72° steep, and backroad variants equipped with conventional wheels have already been impressive in this regard.
More traction thanks to wide tires
Where things get bumpy, more tire volume and lower pressure are of course always an advantage. With the large-volume 650B tire, you don't have to worry about punctures, even at low air pressure, as can happen with narrower tires. Of course, at some point every tire feels spongy; The wider a tire is, the more scope it offers when it comes to the optimal compromise between smooth running, comfort and traction. The WTB Venture, which is installed on the Rose, is even approved for 80 bar pressure for riders weighing up to 1,7 kilos. The tire then presses in so far that the powerful shoulder lugs are in contact with the ground, and not just when leaning in corners, and it bites into pretty much any surface.
The “Mullet” concept also includes other components at Rose. The test bike is equipped with SRAM Force AXS Eagle, whose 10-50 mm ring and the 40 mm chain wheel offer a very wide range of gear ratios. Due to the smaller wheel circumference, all gears are slightly shorter than on a standard gravel bike, which is an advantage on MTB-like tours. The Ritchey brand's strongly flared handlebars, whose ends are anatomically shaped, are unusual. It is very wide at the bottom, not very deep and therefore ideal for demanding terrain and difficult descents. Rose mounts it on all Backroad models with 1x gearbox; These are 28-inch bikes with 44 mm wide tires. Backroads with a double chainring come with conventional racing handlebars and 40 mm tires. This makes an exception Backroad Limited Ekar: 1×13 drive, 40 Conti tires and normal handlebar shape.
Low bottom bracket frame
In comparison with the 28-inch versions, it is of course noticeable that the 650B concept has its limits on the Rose Backroad. This is due to the tire clearance, which is limited to 28 mm for 45 inches and 27,5 mm for 47 inches. So not a big difference; You can't get more tire volume from this bike because of the smaller wheels. In addition, the Backroad's frame geometry is not necessarily ideal for small bikes. The bottom bracket is located 76 mm below the horizontal line through the wheel axles (bottom bracket drop / BB drop), which is quite deep for a gravel bike. Particularly in demanding terrain, pedal contact occurs earlier than with a bike with a higher bottom bracket and conventional wheels.
Rose Backroad AXS – High comfort thanks to the highly flexing support
In addition to sporty driving characteristics and great handling, one of the advantages of the Rose Backroad is its high level of damping comfort. The low seat stays in which the seat clamp is also integrated are noticeable on the rear triangle. From this point on, the carbon seat post can move backwards - the seat tube is open to the rear and covered with a black cover. On the test bike with the seat post extended far, the “flex” is extreme - but anyone who rolls over bumpy roads for hours will love the vibration and shock absorption of the Backroad. This means you can also drive with slightly higher air pressure to avoid bottoming out and reduce rolling resistance.
The wheels could also offer a certain level of comfort: Rose uses its “G-Thirty Disc” wheelset on the 28 and 650B models, which is optimized for wide tires with an internal width of 25 mm and also has super-thin Sapim Laser round spokes (2,0 .1,5-2,0-XNUMX mm). Although they require sensitivity when lacing, they are intended to improve the wheel's own damping.
650B: ideal for smaller drivers
650B on Rose Backroad – yes or no? If you could fit two-inch tires, the smaller wheels would offer an advantage, but Rose doesn't allow that. In our opinion, the concept doesn't really work. However, 650B bikes are very interesting for smaller riders: They particularly benefit from the slightly greater handiness, and the lower bottom bracket also suits them. Choosing the Rose Backroad is definitely a good decision - there are also numerous other variants...