Along with a new Émonda, and carbon mountain bike wheels, Trek/Bontrager also were in the news last week for their new line of Aeolus road wheels. With options from budget to budget breaking, the new Aeolus line has three different tiers – RSL, Pro, & Elite. As part of the launch, Bontrager sent over a pair of their Aeolus Pro 37 wheels for me to check out, while Tyler has been riding the top end RSL.
For a quick refresher, the top two models in the new Aeolus line use a new tubeless ready, disc brake-only rim profile that measures 37mm deep, and 21mm for the internal width. Bontrager’s goal with the redesign was to design a rim that was not only lighter than the competition, but faster as well.
Built using external alloy locking nipples and bladed 14/17/17g spokes, the Aeolus Pro 37 rims are drilled for 24 spokes each. Currently, the wheels are only offered in 700c.
At the center of each wheel, you’ll find a straight pull, centerlock Bontrager branded hub with DT Swiss 350 internals. Out of the box, the hub is compatible with 9/10/11 speed Shimano/SRAM HG Spline cassettes, but since it uses the DT Swiss Star Ratchet system, there are a number of options available including SRAM XDR (which I needed for my build).
The stock hubs on these wheels use the 18t star ratchet, which can be upgraded to the 54t ratchet if desired. In stock setting the hubs are configured for 12 x 100 and 12 x 142mm thru axles. Any changes to the hubs can be made without tools, and very easily at that.
While the RSL is certainly the winner when it comes to weight thanks to the higher end OCLV RSL carbon fiber, the Aeolus Pro 37 isn’t terrible at 1512g for the set (686g ft/ 826g rr). Sure, there are many wheels out there that are lighter at this depth, but at this price point it’s respectable. Note that these were weighted without the tubeless system installed…
To Strip or not?
Each set of Pro 37 wheels ship with both a rim strip to use for standard tubes, as well as a plastic rim strip with a tubeless valve for running tubeless ready tires. Tyler has some thoughts (coming soon) on the weight of this tubeless strip compared to that of tubeless rim tape (which can also be used in lieu of the strip,), but for me I never gave it much thought.
Would tubeless tape result in a lighter system? Probably.
But is the strip easier to install? Definitely.
In order to set these wheels up tubeless, all that’s needed is to align the strip with the valve hole (you can put the tubeless valve through the strip and through the valve hole before installing the strip to get this just right), and snap the strip in place. Assuming you took the advice of using the valve to help line up the strip, all that’s left is to tighten down the valve lock nut, install a tire, add some sealant, and then finish mounting and inflating the tire. Within minutes I had both tires seated, inflated, and holding pressure with minimum effort. There was no need to carefully listen to the rim to find all the places the tape hadn’t quite sealed yet, no need to swish the wheel around to attempt to distribute tire sealant evenly, and above all, no need to add any air after the initial ‘pop’ to seat the tires.
Long story short, for riders looking for the easiest tubeless set up, a few extra grams in the form of a plastic rim strip seems like a worthy trade off. Of course, if you don’t want to run tubeless, the hooked rim profile works perfectly well with the included rim strip to run your favorite inner tube.
Bontrager R3 Tires
Along with the wheels, Bontrager sent over an assortment of tires including 700c x 25mm & 28mm R3 Hard-case Lite tubed tires, and a 700c x 32mm R3 Hard-Case TLR. While the 28mm R3 was a little undersized when running with a tube, the 32mm R3 measured almost exactly 32mm.
Out on the Road
I haven’t chosen to ride tubes on a road bike in years, so the 32mm tubeless options was the clear favorite, and I had a bike in for review that seemed like it may be a good fit. Indeed, with the chainstay at its shortest setting on the Otso Warakin Ti, the wheels and tires ended up being a great ‘all road’ set up for the bike. I should point out that I did have issues with one of the tan wall 32mm R3 tires holding pressure over 60psi. But that seems to be an isolated issue with a single tire – Bontrager sent out a replacement set (that happened to be black wall), and these sealed up just fine, and held pressures above 60psi.
However, the whole set up felt slow compared to my daily driver – a Why PR set up with Zipp 303 Firecrest wheels with 28mm tires. Because of that, I wanted to have a direct comparison so I took the Aeolus wheels off the Otso, and mounted them up to the Why with the same Zipp 28mm tubeless tires, running between 70-80psi. In case you’re wondering how big the difference is between the speed of 28mm vs 32mm tires, it seems to be a lot.
Set up with racier 28mm tires, the Aeolus wheels really came into their own. The Zipps still felt faster on the flats, but the Bontrager wheels feel lighter when climbing. The Aeolus wheels are also one of those aero wheels that reward you for going faster. In this case, on a windy day, riding at any speed over 20mph resulted in rock solid handling. But under 20mph, strong cross winds still made the wheels feel a bit nervous, in spite of only being 37mm deep.
So how do the Aeolus Pro 37s compare to the top end RSL wheels? Well, they’re 187g heavier and lack the updated DT Swiss EXP hubs, but they’re also $1,100 less expensive with a retail price of $1,299 for the set. Add in a lifetime warranty, and Carbon Care Wheel Loyalty program that completely covers the wheels for any damage in the first two years of ownership, and the Aeolus Pro 37s seem like they could be a smart upgrade for someone looking for aero benefits with a reasonable price tag.