ZIPP 303 NSW AND BONTRAGER AEOLUS XXX 4 – BEST ALL-AROUND PERFORMERS
These reviews of the Zipp 303 NSW and Bontrager Aeolus XXX 4 wheelsets first appeared alongside reviews of other all around rim brake wheelsets in my post The Best Carbon Road Bike Wheels.
ZIPP 303 NSW – SAME NAME, NEW ATTRIBUTES, STILL TOP PERFORMANCE
Little more than a year after Zipp introduced its first line of NSW wheels, it came out with an updated line in 2018. The latest 303 NSW is wider (19C), lighter (1510g), and has an updated rim profile. Along with its NSW siblings, the new 303 is the first line of Zipp rim brake wheelsets that are tubeless.
The hubs and brake tracks that were new with the earlier NSW carry over as does its premium price.
I and my fellow testers rated these the Best Performer the last time we reviewed wheels in this category. I wondered if the changes made them any better.
In a word, yes. They are more comfortable on long rides and mixed terrain than before. They accelerate and climb a tad better. They still have an uncanny way of seemingly ignoring the crosswinds. If you run them at lower pressure with tubeless tires, they seem to be even more surefooted than before. If you run them at higher pressures, they feel as responsive as a whip.
My fellow tester Nate, the all-business, often stoic Bullet Train and A group ride leader at my local bike club who also led his race team to another TTT victory and won his age group up the New England equivalent of the Mt. Ventoux climb this year called the 303 NSW “absolutely dreamy.”
Seems the ability to run this 303 NSW carbon clincher wheelset tubeless at <80 psi for Nate, who is all of about 155 lbs/70kg, created what he described as a super smooth ride with great stability and control, soaking up bumps and harsh road conditions.
I seldom hear Nate or the few other super talented and competitive riders I’ve met talk about comfort and stability. This wheelset brought our that reaction.
At the other end of the spectrum, I was surprised to hear my fellow tester Moose, who weighs about 200lbs/90kg (and thus the reason for his nickname), speak positively about the 303 NSW’s stiffness and responsiveness. Zipps characteristically aren’t as stiff as other wheelsets and under Moose’s frame, I thought they might be a tad soft.
Nope. He found them sturdy enough and really liked their responsiveness. Despite the range of alloy and carbon wheels that were shallower and deeper and the same depth as these we rode this summer, he kept coming back to the 303 NSW as the one he wanted to ride for this event or that long weekend away.
When I ride these wheels, I feel like the Wayne and Garth characters from the old Wayne’s World skits who repeated “We’re not worthy” when someone famous invited them to stick around.
Why? When I get the 303 NSWs up to speed, which doesn’t take long, they seem to hold my momentum without me having to work really hard to keep them there. When I go out on a windy day, my 150lb/68kg body can get pushed around but the NSWs seem to anchor me to my line. The wheels are snappy on legs that haven’t had much snap in them for more than a few years now. They also climb easily for me.
The braking on these wheels is probably their most debated characteristic. The performance isn’t debatable – they are as capable on dry roads as alloy wheels and nearly so on wet ones.
Instead, the noise that comes from these brakes creates the greatest divide in the evaluations I and my fellow testers have had and that some of you have shared in your comments in past reviews about other Zipp wheels that use the same brake track design.
While it’s not annoying like the shrieks you have likely heard from older carbon brake tracks and pads, some don’t like any noise while others think the Zipp brake sound is cool. Perhaps the best analog is the reaction people have to noise coming off of freehubs. Some like it while others want it quiet. Ironically, the hubs on the 303 NSWs freewheel without a whisper.
All in, the new 303 NSW is probably the most versatile and complete all-around set of carbon bike wheels a road cycling enthusiast will ever need. A racer might want more of this and not care about that from their wheels but for those of us who enjoy a wide range of riding from individual training to aggressive A and B group rides to long endurance rides to serious climbing to riding at high speeds and want one wheelset to help them deliver great performance and riding experiences from one wheelset, the Zipp 303 is hard to beat.
Am I worthy of this level of performance from a wheelset? Probably not but I’ll gladly take it. And, if I’m going to pay the market price of about $3200/£2600/€3000 from this one, I’ve earned that level of performance or at least bought it. If you want it for yourself, you can find it online at my top-rated stores Competitive Cyclist, Merlin, and others I recommend at Know’s Shop.
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BONTRAGER AEOLUS XXX 4 – RECALLING MEMORIES OF DRIVING A CORVETTE
There’s something about my long-ago memories of driving a Chevrolet Corvette and my recent experience riding the Bontrager Aeolus XXX 4 wheels that connects.
No, it isn’t the phallic imagery of a Corvette and the XXX label of the latest Aeolus, though perhaps you could make that connection. (Sorry that I just did.)
Rather, it’s the rush of rolling at speed they both provide. While a lot of cars and wheels roll fast, it’s what happens in the moment of speed that makes life behind the wheel and in the saddle exciting.
Hitting a turn at speed carries more unknows than rolling straight. The Corvette’s wide wheelbase, wide tires, and low chassis provided me the handling performance to confidently hit every turn faster than I’d ever done before.
Similarly, the Bontrager Aeolus XXX 4 mounted with 25C tubeless tires stick it in the corners. Fellow tester Nate enthused they always seemed so much more planted and stable than any other carbon clincher wheelset he’d experienced, especially in turns with bumpy pavement.
I measured the internal rim width between the bead hooks at 21.1 mm on these and other Bontrager Aeolus XXX series wheels. That makes them the widest rim brake carbon bike wheels we’ve tested, notably wider than most which run 19 mm or 17 mm these days.
Their 27.5 mm external rim width across the brake tracks is nearly as wide as others like the Enve and Zipp in this category. The external rim width along with the mounted and inflated 25C tire width helps contribute the XXX 4’s aerodynamic performance while its wide internal rim dimension and the wheels’ stiffness lead to its great handling and comfort.
Many road disc wheelsets have been at 21 mm internal for a couple of years now and I can confirm riding them is a similar speed-liberating handling experience. The better support a wider rim provides to the sidewalls of the same 25C tire makes a real difference. It’s nice to see Bontrager bringing this to the rim brake world.
Moose took these wheels for a ride down the 8-mile, 8% average grade asphalt road at Whiteface Mountain, home of the Lake Placid Winter Olympics. Hitting speeds of 50 mph, he reported that the crosswinds made the riding the XXX 4s “a little sketchy” but not enough to back off his exhilarating speed.
I don’t know if that’s Moose’s daredevil approach to going downhill on bikes (and skis) that he prefers but I do know he arrived safely at the bottom and was so excited after the ride he sent me a half dozen texts about his descent.
While neither of us could find strong crosswinds, Nate and my experience in moderate ones on these wheels were fine. They did acknowledge the breeze but it didn’t affect our steering or cause us to do anything unnatural.
Unfortunately, you sometimes need to slow down. Fortunately, all three of us were impressed with the braking power and modulation of these wheels on dry roads; they are among the best here.
On wet roads, however, they are no better than earlier generation carbon clincher rim brakes. Like the Vette, leave these Bontragers in the garage when it’s wet outside.
The XXX 4s are “stiff enough” to climb and sprint but they are more above average in this all-around carbon clincher pack than clearly superior compared to others on this criterion. They are considerably heavier than the 1400 grams claimed by Bontrager – 1556 grams on my scale. This puts these XXX 4s are 50-100 grams heavier than most in this rim brake carbon road bike wheels category.
Why is there such a big weight difference? I measured them with the rim strips you need to ride them tubeless. Bontrager doesn’t include the strips in their claimed weight. It’s unusual to have rim strips weigh so much. Most rim tape adds 5-10 grams per wheel. These rim strips weigh about 65 grams per wheel.
I asked the Bontrager support line and a dealer whether I could run them with tape rather than the strips. Neither recommended it. The strips add the height and rim bed gutters you need to get your tubeless tires locked in.
If you want to ride them with a tube and clincher, they will be far lighter. But, to gain the versatility, comfort, and handling that we experienced, run them tubeless even though they will be slightly heavier.
The added weight makes for an average, more dampened acceleration than a lively, springier reaction when you want to accelerate. Their DT Swiss star ratchet hub internals provides quick engagement (and quiet freewheeling) but doesn’t improve the acceleration enough to make a difference.
If you’ve got the watts in your legs, you can probably get these wheels up to speed much in the way a Corvette corals the horses under its hood to get you from 0 to 60 mph faster than most.
It’s what the Corvette and Bontrager Aeolus XXX 4 do at speed, more than how fast they get you there, that separates them from the competition.
You can order these wheels online for $2400 by clicking through on this link to Trek.
So what separates the two Best Performers? The Bontrager XXX4 is the stiffer of the two. That stiffness shows up in more precise cornering and the feeling of more direct power transfer when climbing. The Zipp 303 NSW is a more responsive, more lively ride and feels like it is less work going uphill.
They are both comfortable but the Zipp holds the edge here and it shows up on long rides. Choosing to ride them tubeless, which makes both more comfortable, and where you set the inflation pressure will likely have as much or more effect on your comfort than choosing between the wheels.
The XXX 4 and 303 NSW brake extremely well on dry pavement though the XXX 4 does it quietly. Because the XXX 4 is stiffer, you can set up your brake pads closer to the rims and get better modulation in your braking. If you find yourself riding on wet roads often, the 303 NSW will give you notably better braking.
As a light B group rider, I loved both but preferred the livelier Zipp wheelset and it being totally unfazed by crosswinds. While I prefer a quiet freehub, I wasn’t bothered by the brake noise.
I’d have thought the slightly stiffer XXX 4 would win Moose over but he liked the responsiveness of the 303 NSW and the range of things it did so well.
Despite loving the comfort of the Zipp, Nate gave the nod to the XXX 4 for its better handling and brake modulation. He also felt the way it handled varying terrain would make it a great wheelset to use during cyclocross season.
Performance comparisons and preferences aside, the price of these two wheelsets differs by quite a bit. While neither of these wheelsets is a bargain, the Bontragers are about $800 less expensive. That’s an important consideration if you weigh the price of performance in your decision.
You can compare key performance and other criteria of these two wheelsets against other all arounders in my post The Best Carbon Road Bike Wheels.