Wheel innovation has come a very long way in the last twenty years. While much of the marketing dollars are spent on promoting carbon fiber, the bread-and-butter of the wheel industry is (still) in aluminum. Though price has come down over time, most carbon can’t match aluminum prices, save a few notable exceptions like consumer-direct FLO Cycling. There is an interesting inflection point that occurs around $1,000: Here you find some great high-end alloy wheels… AND the beginning of the carbon fiber market.
Before disc brakes came to road and triathlon bikes, the choice between expensive aluminum and inexpensive carbon often came down to braking performance. Want good braking? Go aluminum. Willing to give that up for the cool-factor of carbon and potential aero gains? Go carbon. Now that disc brakes are becoming more common, the argument to go alloy has become more slippery. Are alloy rims now purely a price-point product? Are there legitimate alloy contenders today? If so – what characteristics do they have? What are some take-homes that will help us pick out the best set of alloy wheels today? Let’s investigate.
Alloy Wheels for Road and Tri in 2019
We have covered several stand-out aluminum performers in the past – the Bontrager TLR series, the American Classic Argent, and the much-loved Zipp 101. They have some similarities and some differences, because while there are different ways to bake a cake, best practices become known. We’ll focus on five key areas:
1. Rim Depth, Width, and Shape
2. Spoke Type, Count, and Lacing
4. Tubeless Compatibility
5. Braking Surface
Rim Depth, Width, and Shape
Rim dimensions have a huge effect on the performance and feel of a wheel. In short, we’ve seen rims get deeper, wider, with more rounded sides.
Adding rim depth improves rim stiffness and also reduces the amount of spoke length that’s exposed – aiding in aerodynamic performance. Adding rim width helps to increase tire volume, allowing for lower air pressure and improved comfort – and arguably better handling. The rub for aluminum rims is that having a rim that’s both deep and makes for something heavy. Because of this, it’s very rare to find any aluminum rims with a depth greater than 30mm, or an outer width of greater than 25mm. Also, I’m not aware of any aluminum rims that have both a 30mm depth AND a 25mm width – as of now it’s either-or.
Perhaps the best outlier in this respect was the now-discontinued American Classic 420. With super-thin construction, it managed to hit an advertised weight of 420 grams per rim with a 34mm depth and 22mm width. While I never used this particular rim, I did test its slightly shallower cousin, the 29.5mm-deep Argent. They were indeed very light given the depth, but the rims were just too thin for my taste. During my test, I experienced a brake ‘tick’ that seemed to be due to either a bad rim joint, or a rim that had become slightly bent during tire installation (due to a VERY tight interface with the tire).
On the other end of the spectrum, you have the Hed Ardennes Plus. While the depth is shallow (24.5mm), the width is massive at 25mm. Overall weight depends on the build and hubs you choose, but figure about 1,500 – 1,600 grams. I’ve ridden and enjoyed these wheels in the past, but even Hed doesn’t try to bill them as aerodynamic. Rather, they’re advertised as do-it-all wheels for daily training, meant for maximizing tire volume.
The best example of an overall aluminum performance package is the now-discontinued 101 from Zipp. This rim (above, left) used the Toroidal patent that was co-held by Hed and Zipp, implementing a smart rim shape with angled braking surfaces. It had a depth of 30mm, a brake track width of 22.8mm, and a maximum width of 24.5mm. When used with a 23mm tire, the rim was wider than the tire (using the Rule of 105 for legitimate aero performance when combined with the curved rim sidewalls). Unfortunately, the rim was very expensive to machine, with no flat surfaces (I know – I was working for Zipp at the time it debuted). With a $1,300 asking price per pair, it just wasn’t a feasible sale with competitors’ carbon rims coming down to match its price. It performed better than many of these carbon competitors – especially when you consider braking performance – but it’s tough to battle the perception that carbon is always better.
Spoke Type, Count, and Lacing
Deeper and wider rims improve stiffness and durability (generally speaking), which allows wheel manufacturers to reduce the number of spokes. While this can go too far, many have settled on a happy medium of 18 front, 24 rear. Another interesting option that I like is rear 2:1 lacing, which ends up with 21 rear spokes (14 drive side, 7 non-drive side). The idea is that, with half as many spokes on the left side of the wheel, it greatly evens out left-right spoke tension disparity caused by wheel dish. As a great example, I’m now testing a set of Vision Trimax 35 wheels (seen above), which uses 2:1 rear lacing. I measured the spoke tension when they were new out-of-the-box, and the non-drive tension is only 20% lower than the drive side – very impressive!
As for spoke type, it is almost universally agreed that the best choice is bladed steel. Carbon or aluminum spokes can work in certain applications, but typically include an unacceptable combination of high price, compromised durability, or poor aerodynamics. Bladed steel is the proven go-to choice.
This one is simple, right? We all like lightweight stuff. As mentioned in the first section, however, sometimes things can get too light, and it’s tough to have it all with aluminum. Some alloy wheels rid themselves of weight by using very small bearings inside very light hubs – but I suggest avoiding these for most people (the low advertised weight seems attractive until you have to replace your bearings every 6 months).
The take-home here is that you’ll have to be realistic with your expectations for aluminum wheels. If you want something that’s 1,200 grams per pair, there will be some durability compromises compared to something that’s 1,500 grams per pair. There’s no free lunch.
Perhaps a good case-in-point is my set of Vision Trimax 35’s in the image above. They have a max depth of 35mm, a width of 22.6mm, and build up to an expected 1,690 grams on my scale. Surely they could reduce this weight, but it would drive the price up and the durability down. I chose them because I wanted something that looked good (i.e. 30mm or more depth), and had a no-nonsense build for longevity.
For better or worse, braking surfaces are becoming less of a key topic of conversation, due to the influx of disc brakes to road and triathlon. For a couple decades, the standard for performance in rim braking had always been machined aluminum (check out this article series for more in-depth information).
While I love a nice machined braking surface, a new style emerged several years ago, pioneered by Mavic. Called Exalith, it uses a unique anodized and textured surface with proprietary brake pads for incredible wet and dry braking. It is used today on several of their wheels, and I wish more people had caught on.
While textured surfaces like Mavic’s Exalith are expensive to manufacture, some companies use toned-down versions or dark-anodized braking surfaces for that popular all-black look. For example, Vision makes a black-anodized “KB” version of the Trimax series, and Hed offers their own take called the BLACK series. Keep in mind that all of these wheels will eventually wear through, since the black anodized surface can’t last forever (be double sure to follow their brake pad recommendations, too).
Tubeless continues to be the hot topic-du-jour for much of the bike business. While it has yet to catch on in masse for triathlon, it’s getting there and some big-name pros are even making the switch. From a data perspective, we haven’t yet seen definitive evidence that tubeless unilaterally improves upon the trifecta of aerodynamics, rolling resistance, and puncture resistance over known high performers, such as the Continental Attack tire with a latex inner tube. Additionally, tubeless requires more maintenance, hit-and-miss fit with various rims and tires, and it can cause a mess of liquid sealant if your airline bike box requires fully deflating the tires. Luckily, Mavic has debuted a new road UST standard (seen above), which should provide a very reliable fit, much like their original mountain bike UST standard did.
Don’t let me talk you out of tubeless, however. Some people swear by it, and with a nice fitting rim/tire combo, it can work well. End of the day, if tubeless is important to you, be sure that your wheels are tubeless-compatible before buying – which is becoming more and more common by the day.
What About Alloy/Carbon Hybrids?
If you like aluminum wheels but want to amp up the performance even more, there are some great options that combine an alloy rim with a carbon fiber fairing. You’ve got the Bontrager Aura 5, the Hed Jet series, FLO Cycling, Mavic, and more. I’m glad that wheels like this have survived, offering all the benefits of aluminum rims with the aero benefit of deep section rims – at a price that’s usually much less than full-carbon clinchers.
What Should YOU ride?
Was that TLDR (Too Long, Didn’t Read)? If so, I’ll give the short list of specs that you should look for with a modern set of aluminum wheels.
1. Internal rim width of 17 – 21mm. Outer rim width of 22 – 25mm.
2. Rim depth of 25 – 35mm. Deeper looks cooler and might gain an aero edge – at the expense of weight.
3. Tubeless compatibility – if that’s your cup of tea.
4. Bladed steel spokes
5. Beware of super lightweight hubs that contain tiny bearings that won’t last.
What if you ride disc brakes on your bike? Luckily, not much changes, other than the fact that you don’t have to worry about braking surface quality. You’ll end up with an all-black anodized rim, along with a disc-compatible hub. Most disc brake wheels have higher spoke counts than rim brakes (typically 24 front and rear) – necessary to safely deal with disc braking forces.
The only thing I wish for the aluminum market is that we can reinject some enthusiasm and development – and hopefully get some good options delivered consistently over time. Aluminum isn’t dead, and won’t be dying soon.