Just In: Bontrager Rhythm Pro Carbon 27.5″ Wheels and XR4 Tires
Light, strong, cheap – pick two. That was Keith Bontrager’s mantra back in the 80′s and 90′s and it still rings mostly true today. The new carbon Bontrager Rhythm Pro wheels look to follow the saying to a ‘t’, built with burly, wide rims, hubs, and Bontrager’s lightweight TLR tubeless set up. While they certainly aren’t cheap, the Rhythm Pros sit in the middle of the carbon
all mountain enduro wheel price scale, with a set of the 27.5″ hoops retailing for $2199.
Offered in all three wheel sizes, the Rhythm Pros claim to offer precision handling on the gnarliest descents, while remaining all-day XC light. We run you through the details straight out of the box, next.
Like many of the Bontrager Rhythm wheels, the Pros use an offset rim design, or OSB (offset spoke bed). The offset means the wheel can be built with less dish and more even spoke tension on both sides for improved stiffness and strength. Even though the spoke bed is offset, the rim channel itself is symmetric which means when you go to install the plastic Bontrager TLR rim strip, you don’t have to worry about installing it the wrong way.
The 29mm wide external, 22.5mm wide internal carbon rim is manufactured from Bontrager’s OCLV carbon fiber, though not in Wisconsin. Some of the Bontrager wheels are still made here, but these rims are manufactured in China though the wheel’s hand assembly is done in the US.
TLR for those not familiar, is Bontrager’s Tubeless Ready system which relies on a plastic rim strip that snaps into the rim and a metal valve with a removable core. The set up allows the use of tubes or tubeless tires with sealant, but is optimized for Bontrager’s TLR tires which have a tubeless bead and a standard casing (not UST).
At the heart of each wheel are these fairly large 6 bolt Bontrager hubs with sealed bearings and their Rapid Drive freehub design. The hubs are connected to the rims with 28 front and rear 14/15g spokes in a stacked, straight pull lacing pattern and held in place with Alpina alloy locking nipples.
Rapid Drive relies on a captured 3 pawl system, each with 3 teeth, which when combined with the 54 tooth ratchet ring results in a 6.67° engagement. The freehub spins on a large bearing pressed into the hub shell, and the axle is supported by a bearing on each end, for a total of 3. To service the hub, simply pull off the non drive end cap and slide out the axle with the freehub body. At this point you could also switch it to the available SRAM XD 11 speed freehub body that is sold separately.
The axle caps are interchangeable, and the wheels include standard quick release end caps for both wheels in the odd chance that you’re riding a 27.5″ bike without thru axles. Out of the box the wheels are set up as 15mm front and 142×12 rear.
Without the rim strips and valves, the wheels weigh 730g for the front and 860g for the rear. At 50g more than claimed weight, the pair comes in at 1590g.
Add in the strips and valves and you’re looking at 780g and 910g, or 1690g total.
We’ll be testing the Rhythm Pros initially with Bontrager’s XR4 Team issue TLR tire. Labeled a 27.5 x 2.35″ the tires weigh an impressive 791g which is still 11g more than claimed. Considering this is an aggressive tire that is tubeless ready in a healthy 2.35″, we’ll take it. The Team Issues feature a 120 tpi Inner Strength casing, and a TLR aramid bead for $69.99.