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Bontrager Aeolus D3 review

Bontrager Aelous D3 wheel
13 May 2015

Bontrager’s new top-end, tubeless-ready carbon clinchers could potentially elevate the latest tyre technology up to race level

It’s taken a long time for tubeless tyres to be accepted in the road market. Frustratingly for those of us who were quickly in favour of this technology, the delays have come from the market itself. Big-name wheel brands have been tentative about fully committing, certainly beyond mid-priced alloy wheelsets, and tyre brands have seemed reluctant to drive the technology forward. As a result, tubeless tyres have been viewed more as hardy mile-munchers than racy options. This new Bontrager Aeolus 5 TLR wheelset, however, could prove to be a turning point.

Easton, to give it due credit, was the first to present tubeless compatibility in its high-end, full-carbon wheelsets (2013’s EC90 55 Aero). With Bontrager joining the fray, and with the aero credibility of its Aeolus wheels already established, there’s likely to be increased interest from those seeking light, fast carbon race wheels.

Plain sealing

Bontrager Aelous D3 tubeless rim

The first hurdle was fitting and sealing the tyres – in this case, Bontrager’s own 25mm R3 tubeless. The wheels come with the tubeless rims strips and valves, so fitting the tyres was straightforward and no more tricky than any standard clincher, save for the noticeable snugness of the bead, which means you need strong thumbs to push the tyre on by hand. I avoided resorting to tyre levers, but there’s no reason not to use them as long as they’re plastic and you’re careful.

I used Bontrager’s own sealant, simply squirted in through the valve hole (after removing the core) before the real moment of truth – inflation. Tubeless systems have a reputation for being troublesome when it comes to getting air into the tyre quickly enough to seat it so you create an instant airtight seal and can continue to inflate normally. Thankfully the Aeolus 5 TLR’s gave me no problems. A standard track pump was all that was required to get the R3s up to pressure. This ability to be ready to ride with such little effort is definitely a feather in Bontrager’s cap.

I’ve ridden the previous generation Aeolus D3 carbon clinchers extensively and I’d put them both among the best I’ve tested. The thought of being able to add in tubeless functionality has real appeal. It’s worth noting that this version has undergone a complete redesign, so you can’t simply fit the tubeless rim strip to an existing Aeolus wheel. The TLR rims are 40g lighter, bringing the total weight for a pair of 5s well under 1,500g, which is impressive for a wheelset of this depth, especially given the chubby 27mm external rim width. The internal rim bed has been widened to 19.5mm (from 17.5mm) in line with the industry move towards wider rubber, thereby improving the profile of a 25mm (or wider) tyre.

To the road

Bontrager Aelous D3 hub

My first few rides were in the mountains north of San Francisco that included the occasional foray onto gravel roads. I decided to take full advantage of the tubeless tyre technology and began experimenting with tyre pressures as low as 80psi. Climbing, the wheels have an energetic feel, their lateral solidity and low mass combining in a way that helps them to whip up hills. It’s especially noticeable on steeper slopes that require bursts of out-of-the-saddle pedalling.

Pointing them downhill is no less rewarding, as the wheels’ stability and speed are just as noticable. Riding over the Golden Gate Bridge was the acid test of the claimed benefits of the wide, blunt rim profile in cross winds. There were very strong gusts, yet the 50mm profile proved immune to wobbling, where a lesser wheel may have had me tangled in the railings.

The additional grip and comfort offered by the tubeless set-up was very apparent. The Bontrager Aeolus 5 TLR’s have been my go-to wheel through several more weeks of testing back in the UK, and in various conditions and over different road surfaces they have continued to deliver impressive results. The overall ride quality is first-rate and I feel like I’ve been able to ride faster through rough sections with no harm to my overall speed uphill or on the flatter, smoother terrain.

Most importantly, a significant amount of gravel riding in the US, plus Dorset’s most rural lanes, have still not managed to inflict a single cut in the tread of the Bontrager R3 tubeless tyres, so I can’t even be sure if the sealant has been effective yet. Suffice to say I’ve had no punctures.

The single factor that has called all this positivity into question has been the braking performance in the wet. The supplied cork brake pads, while excellent in the California sunshine, proved pretty hopeless back home in the rain. A simple switch to SwissStop carbon-specific pads helped to bring the braking back in line with other carbon rims, but at over £2k for the wheels it’s not unreasonable to expect more UK-friendly pads to be included. To counter that, there is a disc brake option, and by eliminating the carbon brake track issue altogether I’d wager this wheelset will be tough to beat.

Bontrager has proved with the Aeolus 5 TLRs that with a lighter, high quality tubeless tyre that’s easy to instal, there are plenty of benefits from this technology, possibly right up to the pro race level.


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