Donnelly is jumping into the 650b mixed-surface gravel road tire game, adapting some of their popular adventure riding treads to smaller, fatter wheels. For smooth terrain, pick the Strada USH. Or when conditions get loose, go X’plor MSO. Both available in two widths, plus several casing options…
Strada USH 650b fast rolling road & gravel tires
The Strada USH is the smooth centerline, herringbone tread shouldered mixed surface road tire from Donnelly, who many still remember formerly as Clement. Designed to roll fast on pavement, but still offer plenty of grip in loose corners, the Strada USH could serve as a all-around hard surface tread from bike touring to everyday commuting.
Donnelly has the most 650b gravel options in this tread pattern, offering it in both a relatively narrow Road Plus 650b x 42mm and a pleasantly wide 650b x 50mm version. The 42mm is said to be designed to match the outer diameter of a 700c x 23mm tire and will be available for just $30 in a wire-bead clincher (580g), $46 in a folding kelvar-bead clincher (500g), and a $72 tubeless ready clincher (544g).
The fatter 50mm wide version is said to match up with the outer diameter of a 700c x 32mm tire. At 1.96″ it is one of the wider Road Plus tires available, and could make for a good option to slap a set of commuting or urban-riding slicks on a 27.5″ mountain bike. The 650b x 50mm tires will be available as $46 folding (610g) or $72 tubeless (644g) clinchers.
New X’plor USH, still only in 700c
For the time being, it looks like Donnelly’s new more aggressive X’plor USH tread with its file shoulder knobs won’t yet get 650b treatment, sticking instead to 700 x35 in multiple casing options, including the 504g tubeless.
X’plor MSO 650b smooth rolling gravel & trail tires
Like the Strada USH, Donnelly’s tightly spaced X’Plor MSO knobs get adapted to Road Plus too. The new 650b X’Plor MSO widens out the all-conditions gravel race tire with its aggressive shoulder lugs making for an adventure riding tire suitable for gravel road, dirt & even proper trail riding. The more narrow 42mm version comes in a $55 folding clincher (510g) or a $67 tubeless-ready (498g) casing.
Also available in a 50mm width, the MSO looks like a fast rolling mountain bike tire that will blur the lines of what your Road Plus gravel bike is really capable of. The 50mm MSO comes in a $46 folding clincher (598g) or the $67 tubeless ready (670g) version.
MXP 650b cyclocross tires
Not to be overlooked in the 650b discussion is a pair of new all-conditions MXP cross tires. Donnelly scaled down their popular MXP to fit to a number of newer small sized cyclocross bikes that switched to 650b wheels for better geometry & fit for small riders. They stay narrow in a UCI race-ready 33mm, but use a nice open tread pattern suitable for a range of conditions and a small-wheel rider not looking for wider tread. The 650b x 33mm MXP is available as $46 folding (320g) & $70 tubeless (430g) clinchers.
As a cross promotion of the new 650b gravel tires, if you buy a pair from Donnelly’s online retail partner ProNet Cycling, they will throw in a free copy of Nick Legan’s Gravel Cycling book.