Early in 2017, Bontrager unleashed a handful of enduro/trail and cross-country wheelset options to help make upgrading to a stronger and lighter wheelset more affordable. One offering from Bontrager is the Line Pro 30, which offers a hook-bead carbon rim with 29 mm internal /36 mm external widths. The Rapid Drive 108 hub (Shimano 10/11-speed or SRAM XD driver) is laced in with 28 DT Swiss Aerolite 14/17 gauge spokes and Alpina alloy locking nipples. The Rapid Drive hub offers 108 points of engagement utilizing a six-pawl, 54-tooth drive ring for durability and easy servicing.
We’ve been riding a few sets of these wheels on hardtails and full-suspension trail bikes. The majority of the time a 2.3 or 2.4 tire was mounted, and the 29 mm internal width rim created a more voluminous tire profile and the ability to run a slightly lower tire pressure without fear of bottoming out on the rim. Lower pressure, more traction, more confidence, more fun. Recently, we’ve had luck running Bontrager’s XR4 2.6 tire on this wheelset. Depending on the tire profile, this rim will happily run tires within the 2.25-2.6 range with success.
Bontrager seems to have found that happy place between stiff and compliant for its carbon hoops. They provide that instant responsiveness and predictability that many of us have grown to love without every root or rock shooting jolts through your body. The Rapid Drive 108 hub hums along at a reasonably audible level; it is certainly louder than a DT Swiss 240 but not quite as conversation-killing as an Industry Nine or Chris King. For a hub that offers 3.3 degrees of engagement, I really didn’t notice much resistance in terms of drag. Typically, I find other high-engagement hubs to have a bit of drag before they start to bed themselves in and settle. Overall, zero issues with the hubs.
Rims, on the other hand, are a different story. Within the testing year, both rims on the original wheelset cracked. Trek stated this was due to the rim’s finishing process. In order to apply the final-finish clear coat, the rim must be hand sanded for the finish to adhere, and during the initial production run, some overzealous sanding lead to thin sidewalls. Bontrager quickly discovered the error and resolved the issue. The other two sets of wheels we’ve been on are problem-free. If you were to have a similar issue, all Bontrager carbon wheels come with a two-year warranty as well as a crash replacement policy that offers wheel replacement for around half the original retail cost.
Actual weight: 1,794 grams.