Stiffness-to-Weight/Power Transfer

The Bontrager XXX disappears on the foot, which is perhaps the highest compliment you can give a shoe. The upper is perfectly stiff and rigid, while the sole, made up of Bontrager’s Platinum Series Carbon, is the stiffest Bontrager tested. This manifests in no energy-stealing flex when out of the saddle sprinting, climbing or when grinding out the long miles. The Bontrager XXX heel is a bit low, which you only notice when walking, and the stack height felt slightly taller than other shoes we rode.

Part of the reason that the Bontrager XXX fades away when wearing it is because it is so light. At 220 grams (7.75 ounces for size 10.5 U.S.), it is among the lightest shoes we tested. When mating the weight with the stiffness, you are clearly getting a race-oriented option.

Fit/Comfort

The synthetic upper is relatively light and pliable, enabling it to wrap around the foot nicely, the Bontrager XXX has a comfortable fit on the foot. We noticed some slight discomfort in the toe box which was interpreted as hot spots generated from some movement (a roomier toe box than some). The tongue of the shoe, which is also synthetic, was unusually comfortable, though it needed to be set correctly or it wanted to wander. The carbon foot bed perfectly contoured to testers’ feet. The heel cup is grippy preventing any heel lift in our testing.

Closure System

Dual Boa IP1 dials perfectly draw in the mid-top of the foot, with mirco backwards and forward dialing. They also feature a quick release, where a simple tug on the dial will immediately release the tension. Given most all shoes use the same dials in different configurations, we have witnessed how the same product (the Boa dial) can work in diverse setups. This particular set of of two dials mounted to the side, and dual laced across the shoe tongue and shoe the shoe itself is unusually good. The bottom strap is Velcro, and mostly likely will get set once and forgotten. The interior of the shoe features one more seam than most shoes we tested, toward the midfoot, however the seams where not noticeable when riding.

Construction/Durability

The synthetic upper of the Bontrager XXX appeared to wear well under our test conditions. It did scuff, which is to be expected. The stitching looks quality, and overall impressions of the shoe are of solid construction practice. The glue lines look very clean. The interior construction is good, with a durable and abrasive material in the heel which will protect a spot on the shoe where we often witness wear.

Drainage/Breathability

The Bontrager XXX has two huge vents at the front of the shoe featuring a mesh material. We experienced reasonable air movement through the venting, although this shoe was warmer and less breathable than some we tested. The vents continue, albeit quite small, on the sides of the shoe toward the back. Overall air movement was a weakness on the Bontrager XXX. Conversely the strength of the shoe is that it is warm, making it an excellent off-season rider. Drainage is better than most with three ports in the sole to allow moisture to escape.

Value

Given that the XXX is the stiffest shoe in the Bontrager lineup, and also one of the lightest, one might expect it to also be the most expensive. At $400, it was priced middle of the pack among our high-end shoes.