Thin Crust vs. Deep Dish - Choosing Gravel Wheels

In 1984, in response to what the ‘old masters’ saw as crimes against pizza by fast food chains and others around the world, the Associazione Verace Pizza Napoletana was born in Italy with a mission to clamp down on impostors by imposing a strict certification process to sell “Neapolitan Pizza.” The AVPN's advocacy succeeded, and now "Neapolitan Pizza" is similar to terms like ‘bourbon’, ‘champagne’, or ‘tequila’, with stringent controls around its use. Instead of dictating new oak barrels and mash bills, these crusty Italians focused on other specifications like types of tomatoes allowed, percentages of flour grades, and crucially, that dough must be rolled out to no more than 3 millimeters thick before baking for 60-90 seconds at 485C (905F).

At the other end of the spectrum, there’s deep dish and stuffed pizza hailing from Chicago. These multi-inch thick creations are probably sacrilege in the eyes of traditionalists in Naples, but they share basic ingredients and geometry. They appeal to different folks at different times, and some people wouldn’t be caught dead eating one or the other, but at the end of the day they’re both pizza and good for a meal.

Point being, while there’s an enormous amount of variety in ‘pizza,’ there’s possibly even more variety in the world of ‘gravel.’ This is something I’m going to explore and showcase over a few pieces. Rightly or wrongly, everything from Specialized’s Crux to Surly’s much loved, long running, and now discontinued Cross-Check get placed under the same umbrella. The breadth of gravel is similar in many ways to mountain biking, and much like no one is cross-shopping a Santa Cruz Megatower with a Trek Top Fuel, no one is is flip-flopping between the Crux and Cross-Check.

Temporarily setting aside geometry, one of the main components defining a bike’s character is the rolling stock: wheels and tires. Fast, slow, thick, thin, heavy, light… the big round bits on a bicycle have an enormous amount of control over what use cases a bike will excel at, how it will ride, and what it will cost. This is especially true for bicycles without suspension, as wheels and tires will provide the majority of compliance, this is where we’ll first delve into different types of ‘gravel’.

A Tale of Two Pizzas

First up, we have the artisanal thin crust* variety: the Crankbrothers Synthesis Gravel wheelset where “a shallow, compliant rim profile allows Synthesis Gravel to absorb and dissipate trail feedback.” These low-profile rims are marketed around comfort, compliance, flex, and of course durability for adventure and long distance rides.

In the other corner, we’ve got a midwestern** deep dish antithesis: the Bontrager Aeolus 49V, billed as “the ultimate aerodynamic road disc upgrade… brings leading aero performance to wider road and gravel wheels and tires.” While the new OCLV thermoplastic is designed to smooth vibrations, the marketing copy speaks to this adding speed and confidence over straight comfort.

*clearly, we’re not certified to use “Neapolitan”

**Wisconsin not Chicago, but close enough

• Yes, different tires are mounted on each rim in the photos. Most of the review period was on 38c Pathfinder Pro tires for both wheelsets, don't worry. I'm not that daft.
• Yes, the degrees of engagement are very different, if that matters to you. The Crankbrothers ride on a star ratchet (the DT Swiss patents recently expired, if you're wondering why there's suddenly such a plethora of options here) system, and the much higher engagement Bontragers are a traditional pawl setup. I had zero problems with either setup
• There were zero reliability issues on either wheelset during the review period.
• The Crankbrothers Synthesis are specially tuned rims for front and rear, available in 650b, and also have an aluminum (and much cheaper) counterpart on the same hubs.
• The Bontrager Aeolus 49V are also available in 37mm deep format, laid up in "laser machined" molds in the USA, and receive no sanding or other treatments once removed from the molds. This, coupled with the supposedly 100% recyclable nature of the OCLV Next construction significantly reduces the environmental footprint of these rims.

What we have are two very different looking wheelsets that are (ballpark) the same price and weight. So what's it like to actually ride them, and why would you choose one over the other?

Riding Impressions

Given the similar weight and width of both wheelsets (and control tires), most ride quality aspects are down to rim and spoke differences. And overall, the difference isn't as massive as you might expect. The Aeolus wheels certainly have a high-strung, high-performance sound and feel. Perhaps it's a touch of resonance in the big wheel cavity, but it's something you can hear from a distance on deep road wheels, especially when they're going fast. Whether real or imagined - I have no rigorous method to find out - this lead to the Aeolus feeling faster. As you'd expect, they can be a bit of a handful in heavy crosswinds.

In contrast, the Synthesis feel somewhat 'dead'. This isn't a bad thing, presumably it's a function of design and the wheels absorbing vibrations as advertised, or in the words of the AVPN's dough requirements "...soft, elastic, tender and fragrant." I didn't notice lateral compliance - not that you're loading gravel wheels up like you can on a mountain bike - but Crankbrothers specifically suggests this as an attribute, so perhaps it's a factor in the deadened ride feel.

Other notes

My one real world problem with either set of these wheels was that I installed several sets of tires throughout testing, and while some were worse than others, they were all a bit challenging to get seated tubeless. There are no real excuses for this in 2023, when certain brands like We Are One have it so dialed.

The Crankbrothers weren't the best, but I did use a compressor for most installations. The 49V had one of the most challenging tubeless installations of my entire life - this leads to a complex relationship, as I love the look of these rims up close and from afar. The subtle way the branding is embedded and the deep, chunky rims just look... right.

Bontrager also sent a set of their 40c GR2 gravel tires, which I enjoyed but due to the small diameter nature of the knobs felt a touch slow on tarmac, and they squirm a bit too much for comfort cornering at speed. Once offroad, the casing was very comfortable and they provided good predictable grip while rolling fast. I ripped a hole in one after 30 kilometers, but it was absolutely my fault (found a jagged piece of angle iron trying to take a shortcut and pass a friend...). Once patched from the inside, I had no further issues.

Conclusions

When its all said and done, we're back to picking between Neapolitan and Chicago deep dish pizza. Visually they're distinct, and they're undeniably different experiences. Both have their evangelists who wouldn't dream of touching the other variety; my reality falls in the middle where either 'za is acceptable. Sure, I might prefer one over the other some days and access to both is great, but there's enough overlap and commonality that I'll take whatever I can reach as long as they're made with care and quality ingredients.

For me, having access to both wheelsets has been great; the Synthesis are now wrapped in some 45c Maxxis Ramblers, and the Aeolus in some race-ready 40c Maxxis Reavers (review on both upcoming). It's the classic mountain bike "trying to have two bikes by having two wheelsets" philosophy, just with more bar tape and skinnier tires.

If you're choosing between these two wheelsets, I'd suggest that while each excels at a different end of the spectrum, either wheelset is perfectly capable of covering the full gamut of 'gravel' riding. Sure, if you're in a party shirt with a Wald basket the Crankbrothers comfort is probably better suited, and yes if you're trying to KOM that river levy, the Bontragers are a better tool for the job but overall, either is going to do just fine on that long weekend bikepacking trip or first 'cross race.

Brass tacks - I'd happily recommend either wheelset if they're in your budget.

Crankbrothers Synthesis Gravel: 1,499 USD
Bontrager Aeolus 49V: 2,399 CAD / 1,799 USD