A 2026 Cervélo Áspero-5 Force build — and it’s not stock. Two changes from the factory spec: the drivetrain went from the XO Transmission mullet setup to a cleaner Force XPLR 1×13, and the wheels went from Reserve GR 40/44 to Zipp 303 Explorers.
The Drivetrain Change
Why Swap the XO Transmission?
The Áspero-5 Force comes stock with a mullet setup — SRAM XO Transmission mountain bike cassette and derailleur paired with the Force levers and a 48T chainring. Cervélo did this to maximize range. Steve gets why. But his view is that around here, and for most of the riders buying Áspero-5s, that super-wide mountain bike cassette isn’t what you actually want.
This bike, in Steve’s words, is a fast aero all-road bike first. The majority of Áspero-5s that have left the shop have been used as road or all-road bikes — not full-on gravel race machines. The XO Transmission setup gives you a ton of range, but the Force XPLR 10-46T 13-speed cassette is what he’d ride personally.
On the cassette: The Force XPLR 10-46T runs 10, 11, 12, 13, 15… Steve’s one wish would be a 14-tooth cog in there. The granularity at the top end isn’t quite as tight as Campagnolo Ekar’s locked cogs, but it’s close. For the flat-to-rolling terrain around here, this cassette makes a lot of sense.
One By — Where Steve Lands
The 1x conversation never really ends but Steve’s position is clear: most riders around here will end up on a 1x setup. It’s simpler, it works, and for terrain where your climbs top out at a couple of minutes, the range of a 10-46T cassette with a 48T ring covers everything. If you live somewhere genuinely mountainous, that calculation might be different.
The Wheel Change
Reserve GR 40/44 to Zipp 303 Explorers
The stock Reserve GR 40/44 wheels come with the Vittoria Corsa Pro Control in 42c — tires that aren’t available for separate purchase at time of recording. Steve was curious about the Zipp 303 Explorers with their wider rim profile and 45mm tires, and the bike was in the shop, so he swapped them. The clearance works fine — the Goodyear tires designed for those rims fit inside the Áspero-5 frame with room.
He hasn’t put serious miles on the 303 Explorers yet to have a real opinion on how they roll. If you’ve ridden them, drop a comment — he’s genuinely curious how they compare to the Strada Bianca in real-world feel.
What Kind of Bike Is This Actually?
The Áspero-5 caught some heat when it launched because it’s specced for 45mm tires instead of 50mm. Steve’s take: that’s the right call for what this bike actually is. By his understanding, going to 50mm clearance — and the frame changes that would require — carries a significant aero penalty, so keeping it at 45 was the right move. And the reality is most people buying Áspero-5s aren’t going to Unbound. They’re riding roads and mild gravel around here, doing some all-road miles, maybe the occasional gravel event.
This is effectively an S5 that fits 45mm tires without the TT headtube. Think about it that way. It’s a sporty performance all-road bike that happens to clear 45s. Call it a gravel bike if you want, but most of the use cases for it are closer to performance road than rugged gravel.
A fast all-road bike that happens to clear 45s
The Áspero-5 Force modified with XPLR drivetrain and Zipp 303 Explorers is a cleaner, more road-oriented build than the stock mullet spec. For the way most of these bikes actually get ridden — pavement primary, gravel capable — the Force XPLR setup makes more sense than the wide-range XO Transmission. The frame is fast and versatile. Build it for what you’re actually going to do with it.
Questions About the Áspero-5 or Custom Builds?
We carry Cervélo at Maklin Bike Shop and can build to spec. Reach out and we’ll talk through what makes sense for your riding.