BONTRAGER AEOLUS PRO 51 – QUIET COMFORT, LACKLUSTER RESPONSIVENESS
I had high hopes going into our testing of the USD$1500, £1250, €1400 Bontrager Aeolus Pro 51 TLR wheelset. We rated its shorter and similarly priced sibling, the Aeolus Pro 37 a Best Value for its capable range of performance. And our review of the Aeolus Pro 51’s more expensive twin, the Aeolus RSL 51 that shares the same rim profile carried the headline: The Definition of an All-Around Road Disc Wheelset.
I and probably many of you keep on the lookout for that value-priced wheelset that rides nearly as well as one that costs twice as much. Using a set of performance criteria (not specs) to evaluate wheels, my fellow testers and I have ridden over a dozen value-carbon road bike wheels (and another half dozen gravel ones) over the last few years in search of one that would save you a bucket full of money without giving up more than a shot glass worth of performance.
Unfortunately, the Bontrager Aeolus Pro 51 isn’t it.
Like all but a few wheelsets in this price range, the Pro 51 performs adequately in some areas and less so in others. From the rides that fellow tester Nate and I did, however, the Pro 51 doesn’t match or approach the overall performance we enjoyed of its RSL 51 sibling or the balance of good performance across areas like its shorter Pro 37 kin does.
Comfort is the Aeolus Pro 51’s biggest strength. Its wide rim profile allows you to run 28mm tires without sacrificing aero performance while keeping the pressure low enough to soak up the bumps on paved, poorly paved, or unpaved roads quite nicely.
True, the right tire and pressure are a big part of enjoying a comfortable ride these days. But I’ve ridden enough wheelsets, especially in this value-carbon price range where the rim/spoke/hub component choices, lacing, or assembly didn’t enable enough vertical compliance in the wheels for a comfortable ride regardless of the tires and range of pressures I tried.
The Pro 51 felt planted in corners though accelerating out of them was underwhelming. They’re stiff enough to confidently get you through but not responsive enough to get you flying out.
That lack of responsiveness also showed up during acceleration efforts. They were not at all lively. It took a lot of effort to get them up to speed.
Once up to speed, it took more effort to keep them there compared to similar depth wheels at this price point and more expensive ones. That was disappointing since the Pro 51 uses the same rim shape as the RSL 51.
While aero performance, which we judge based on our ability to maintain momentum in the 20-25mph/32-40kph range for the RSL 51 was good but not exceptional compared to top-performing all-arounds, the Pro 51 isn’t on par with the RSL 51.
The common rim profile gene did show up in the Pro 51’s good stability in side winds. That’s a welcome benefit if you ride where it is regularly windy.
Climbing with the Pro 51 was a drag, figuratively and literally. Even riding a course with rolling hills took more effort than a wheelset this depth should. 7% grade climbs put me in the hurt locker the way 10%+ ones normally do.
All of this made me feel like I had “dead legs” when riding the Pro 51. I do get those days regardless of the wheelset and certainly feel that way when trying to climb or ride aggressively on most 60mm deep wheels rather than the straight flats they are designed for. But, I should feel better than that on a good set of all-around wheels of the Pro 51’s depth and profile.
Nate put a finer point on it, saying the Pro 51 wheelset’s responsiveness was “dull.”
The Aeolus Pro 51 measured 1625 gram weight likely contributes to its relative lack of responsiveness, acceleration, and climbing ability. That measurement is with about 15 grams of tubeless rim tape and no valve stems. If you instead install the 60-gram per wheel plastic tubeless strips that Bontrager includes in the box, well we’re getting into stock wheel weight territory.
Even with the TLR rim tape, the Pro 51 is almost 200 grams more than the RSL 51 (1441 grams measured) and even 50-100 grams more than my top-rated aero wheels that are 10mm deeper and, well, more aero.
I don’t know how much of that extra weight is in the rims where it matters most vs. in the hubset. Bontrager uses the DT Swiss 350 hubs in their Pro line of wheels which, while heavier than the DT Swiss 240 EXP, are infinitely quieter. Quieter as in absolutely silent.
While there may be a performance difference between the 240 and 350, I can’t feel it on the road. But I sure do notice the solitude of a quiet freehub.
As mentioned, the Pro 51 rims are wide measuring 23.2mm inside and 30.9mm outside with an actual depth of 51.5mm.
As with all Bontrager carbon wheels, their crash replacement policy and warranty programs are very strong. They will replace or repair your wheelset for free within 2 years of when you bought it no matter how it gets damaged and provide a 50% discount to repair or replace them for as long as you own them after that.
They also offer a lifetime materials and workmanship warranty. You can return them if unused within 30 days for a full refund.
Generally, I’ve found Bontrager wheels to be well built and long-lasting. The DT Swiss hubs are proven.
If you want to use these tubeless, I recommend you tape the rims rather than use the plastic strips that come with the wheels. While you need to buy Bontrager’s $25 TLR Rim Tape separately from their site, it’s both lighter and the best tubeless rim tape I’ve used to date. Beyond their excessive weight, the plastic strips are a PITA to install and center and I’ve had them crack on me when installing some before.
Hopefully, Bontrager will start including rim tape in the box at some point. They do include easy-to-install cloth rim straps if you plan to use clincher tires or tubes instead of sealant in your tubeless tires.
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First published on June 2, 2022. The date of the most recent major update is shown at the top of the post.