ProTaper 35mm and 31.8mm Clamp Diameter Carbon Handlebars Tested

The bulk of our mountain bike and component reviews focus on our sixth or seventh felt sense that’s characterized by directly experiencing something. What informs this felt sense and gives it some validity? Well, a massive cognitive library of other experiential knowledge that things can be compared to is one of the most useful assets for any mountain bike journalist. For example, when I review a new carbon fiber handlebar I can compare it to the twenty-plus other handlebar shapes and brands I have ridden this season, and far more from the past. That’s exactly what the review below is all about: What the ProTaper Carbon Handlebar feels like.

When I built up a new Norco Torrent steel hardtail this spring I decided to futurize the controls a little by installing a 35mm-clamp handlebar. Though I don’t need my bars any stiffer, the industry has been shifting toward this larger clamp and I didn’t want to be stuck with stems and bars that are incompatible with the new versions in two years when the ol’ 31.8 standard is retired. Remember the 25.4mm and 26mm diameter bars?

I also tested the ProTaper MTB Meat Hammer Grips on this 35mm handlebar and found them soft and cozy. I prefer my fingertips to barely touch my palm when wrapped around the grips, and these were a little too fat for my liking. They otherwise feel fantastic and will work a treat for anyone who prefers a more ample handle.

Like many of the 35mm clamp bars I have ridden, the ProTaper Carbon are too stiff for my Goldilocks wrists. No matter how I adjusted the fork, swapped grips, or changed my hand position, my wrists were hurting at the end of rides. I’ve ridden hardtails throughout most of my life without wrist pain and held other 35mm carbon handlebars that didn’t leave me with that sting. These simply feel too rigid for me, and fortunately, ProTaper makes an identical bar with a 31.8mm clamp diameter.

Both bar diameters come in a single 810mm width, with cut marks to make them narrower. There are textured surfaces at the stem, control, and grip clamp areas to give the clamps a positive purchase without over-tightening anything, and painted lines to align everything symmetrically. ProTaper says that the lightweight carbon bars use a Plastic Foam Lamination process that “uses less excess resin and fewer plys, resulting in a 15% lighter bar.” My trimmed 35mm handlebar weighs about 178g, which seems fairly light indeed.

Other measurements for these carbon fiber bars include a 25.4mm (1″) or 12.7mm (1/2″) rise selection, with a 4° up sweep and 8° back sweep on either size or clamp diameter. The sweep angles feel natural and comfortable, with a similar shape to that of most other bars I have used. Apparently I can adapt to handlebar geometry more easily than stiffness, as I rarely find issues with sweep.

The Pro Taper MTB Stem uses Torx bolt heads that are harder to strip over time.

The bike that I mounted these bars on has a 450mm reach, and the original 35mm ProTaper MTB Stem placed the controls a touch too close for comfort. I later bumped the bars out with a 45mm stem and at a 780mm width, and they feel much better. I’ll be cutting them down to 760mm soon for some cornering experiments.

Following some recovery time and a thinner Pro Taper Carbon Team Issue 31.8mm bar on the bike, my wrists are feeling healthy and strong again. While a load of components have changed between these two photo sets, I kept all of the components consistent between swapping the bars to help limit the number of factors that could be causing pain — only making other changes once I found the culprit.

At 69kg (152lbs), geared-up, the 31.8mm clamp makes for a bar that’s plenty stiff for any sort of gravity riding I do. I have a relatively forward riding position over the 150mm fork on this bike, and no amount of my weight or force has made these bars feel flexy. I genuinely hope that brands continue to make smaller clamp diameter bars for lighter-weight riders, at least until they figure out how to make 35mm bars a touch more forgiving.

At $164.99, this carbon fiber handlebar is one way to shave some serious grams from the front of your bike. Provided you buy the correct diameter for your arm comfort and riding style, they make a great helm. As stated, the familiar geometry feels comfortable on the trail, with no awkward angles to adjust to.

⭐️ Available online at JensonUSA and Tree Fort Bikes.

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