Zwift Bike Upgrades: Do Smaller Riders Get the Same Gains?

When I first started digging into Zwift’s Bike Upgrade system, I went down the same rabbit hole as everyone else—reading posts, comparing charts, and trying to figure out which upgrades were actually worth it. On paper, it all seemed pretty straightforward. The catch is that almost all of it is based on the “average” rider—around 183 cm and 75 kg, which wasn’t exactly a surprise.

But what if you’re lighter, sitting somewhere in the 50–60 kg range like me? Do those same upgrades really deliver the same gains, or does the math work out a little differently?

Before we dive in, here’s a quick overview of how Zwift’s Bike Upgrade system works.

How the Upgrade System Works

Every bike in Zwift belongs to one of three upgrade schemes, based on what you ride to earn progress toward upgrades:

Scheme	What counts	Typical bikes
Distance	Kilometers ridden	Almost all road bikes (Dogma, Tarmac, Aeroad, etc.)
Duration	Hours ridden	Time trial bikes only (Cadex Tri, Felt IA, Pinarello Bolide, etc.)
Elevation	Meters climbed	Climbing bikes + mountain bikes (Aethos, Emonda, Scott Spark, etc.)

The five upgrade stages:
Each bike has five upgrade stages. Not all stages improve performance:

Stage	Type	Effect
Stage 1	Performance	Aero improvement
Stage 2	Performance	Weight reduction (climbing benefit)
Stage 3	Performance	Drivetrain improvement (both terrain types)
Stage 4	Performance	Aero improvement (mid/high-end) OR 5% Drops bonus (entry-level)
Stage 5	Bonus	Weight improvement (high-end/halo) OR 5% XP bonus (entry-level) OR 5% Drops bonus (mid-range)

Upgrade Tiers and Requirements

Bikes are further classified as Entry-Level, Mid-Range, High-End, or Halo within each scheme. Higher tiers require more riding and more Drops to unlock each stage, but the maximum performance gain is the same across tiers.

Distance-Based bikes (most common)

Tier	km per Stage 1	Total km (all stages)	Total Drops
Entry-Level	100 km	800 km	400,000
Mid-Range	160 km	1,200 km	750,000
High-End	200 km	1,600 km	1,900,000
Halo	550 km	8,000 km	10,000,000

The Tron bike (Zwift Concept Z1) is the most sought-after Halo bike and requires upgrading three Zwift-brand bikes before it can even be started. A full Tron upgrade takes about 8,000 km.

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Performance Gains by Bike Type and Terrain

This is where things start to get interesting. Let’s put the published performance gains side by side with what “the rest of us” actually experience and see how they compare. For each scheme—distance, duration, and elevation—we compare Zwift Insider’s testing at 300W / 4 W/kg on a 183 cm, 75 kg rider with OWL.Bike’s testing at the same 4 W/kg on a 165 cm, 50 kg rider.

Time savings = seconds saved across a 1-hour ride compared to Stage 0.
Power savings = watts you could reduce and still maintain the same speed as an un-upgraded bike.

Note: Stage 1 is an aero upgrade, so the climb benefit is tiny (2.4 seconds). Stage 2 is a weight upgrade, so climb performance jumps massively—from 2.4 seconds to 25.6 seconds. Stage 3 adds drivetrain benefits for both terrain types.

A Reality Check on W/kg

Let’s be realistic for a second. There just aren’t that many women aged 55+ on Zwift racing at 4 W/kg. And while Zwift Insider uses that number as a standard benchmark, it probably doesn’t reflect where most riders on Zwift actually are—across all age groups. For a lot of us, especially older or lighter riders, that target just isn’t representative of real-world racing.

That’s why, for this analysis, I’m shifting the focus to smaller riders and women 55+—the riders I’m actually trying to understand here. So instead of 4 W/kg, I’m working with 2 W/kg, which feels a lot closer to reality for the group I’m interested in.

Instead of adding more tables, let’s get down to the performance gain for women in this group compared with the Zwift Insider benchmark rider:

• ~6-7% less effective performance gain on the majority of the course
• ~10% more effective on the climb segment itself—specifically with the climbing bike

Climbing Advantage: Real or Overstated?

You can’t treat climb time savings as if they automatically carry over to your total course time—they don’t. On routes like Uber Pretzel or London PRL Full, climbs are only one piece of the puzzle. There are long flat sections, descents, and lead-ins where raw watts matter more, and that’s where heavier riders tend to have the advantage. So while a 50 kg rider at 2 W/kg might see a real benefit from upgrades on the climb itself, that advantage doesn’t translate cleanly across the entire route.

On the climbs, though—especially when using a dedicated climbing bike—lighter riders are actually getting about 10% more out of each upgrade compared with the standard benchmark. The gains are real, and they’re meaningful. But here’s the catch: most Zwift routes aren’t climb-heavy enough to justify racing on a climbing bike in the first place. Since the majority of any given course is still flat or rolling terrain, you’ll usually end up choosing a more balanced or aero setup, which limits how often you can fully take advantage of that extra climbing efficiency.

The climb advantage is real—but it doesn’t translate cleanly across the entire route.

That climb advantage only turns into a meaningful course-level benefit on pure climbing routes like Alpe du Zwift, Ven-Top, and Road to Sky. On mixed or flat courses, the heavier rider at the same W/kg will usually finish faster. The upgrade helps you climb faster than you would have without it—but it doesn’t close the gap against a 78 kg rider holding 3 W/kg on Watopia sprint circuits or the Tempus Fugit loop.

So who actually gets the biggest advantage from bike upgrades on Zwift? The answer isn’t as straightforward as it might seem, because it depends on rider weight, power output, and the type of course you’re riding. What looks like a clear win in one scenario can shift quickly once those variables change.

Scenario	Upgrade effectiveness vs 75kg benchmark
Pure climbing routes	~10% better—50kg 2W/kg earns more time savings from same upgrade on the climb
Mixed/rolling routes	~6-7% worse—Climb advantage doesn’t compensate for flat/descent disadvantage
Flat TT / criterium	~6-7% worse—flat upgrade benefit is smaller for the lighter rider

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How the Schemes Stack Up

Before we get into your upgrade roadmap, here’s where everything we’ve covered lands in one view. Below are two comparison charts: one for entry-level bikes across all three upgrade schemes, and one for high-end bikes. Each shows the full upgrade time savings and power saved on both 🚴‍♀️ flat and 🏔️ climbing terrain—for the 75 kg benchmark rider, the 50 kg rider at 4 W/kg, and the 50 kg rider at 2 W/kg.

The high-end distance bike barely beats the entry-level one in performance gain—40.8 seconds vs. 39.7 seconds on the climb at 2 W/kg. Zwift Insider’s data confirms this: at Stage 5, performance gain for all distance bikes are within about a second of each other. Both entry‑level and high‑end distance frames do travel faster than they did at Stage 0, but the upgrade gains stack on each frame’s original performance. That means a fully upgraded premium frame still finishes ahead of a fully upgraded entry‑level frame.

The high-end TT bike pulls a little further ahead on the flat—29.0 seconds vs. 29.3 seconds for the entry-level TT at full upgrade. The TT bike’s flat dominance doesn’t disappear at lower power—it’s still saving you 45 seconds on the flat even at 2 W/kg.

The high-end climbing bike edges out the entry-level one too—66.7 seconds on the climb at 2 W/kg vs. 64.6 seconds. But the 2-second difference across a full 60-minute climb is marginal compared with the Stage 2 weight upgrade that delivers most of the gain.

What It Means for Your Racing

For 2 W/kg featherweight riders racing pure climbing routes: the climbing bike is your highest-return on investment, full stop. Stage 2’s weight upgrade saves you 53 seconds on the climb—more than any other upgrade on any other bike. Stage 3 pushes that to over a minute saved on the climb itself. On pure climbing races like Alpe du Zwift, Ven-Top, or Road to Sky, that extra minute could be the difference between hanging with the front group and watching it ride away. On mixed routes like Uber Pretzel or London PRL Full, it helps you climb faster than you would have without the upgrade—but the flat and descent sections still favor the heavier rider with more raw watts.

For stronger featherweight riders at 4 W/kg, the climb advantage still holds for the lighter rider. But don’t expect the climbing bike’s weight upgrades to close the flat performance gap against a heavier rival holding the same W/kg.

Stage 1 for TT bikes is the one upgrade that pays off for everyone on the flat.

The one upgrade that pays off for everyone on the flat is TT bike Stage 1. It saves 31.8 seconds on the flat in a single unlock, regardless of your weight or power output. If you’re racing a flat individual time trial (TT) or a Team Time Trial (TTT) and you already have a TT bike, it may be worth unlocking Stage 1.

Or does it?

That’s the real question. The CADEX TT looks like an obvious priority on paper, but when you start factoring in rider weight, course profile, and how much of the route actually rewards aero gains, the answer gets a lot less clear. In the next article, I’m going to put the CADEX TT under the microscope and ask the question that really matters: is it actually the best upgrade to chase first, or are lighter riders better off investing their Drops somewhere else?

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The Takeaway for Smaller Riders

Zwift bike upgrades don’t impact all riders equally. For smaller riders, especially those in the 50–60 kg range, the gains can look a bit different than the benchmark numbers you see online. Upgrades can absolutely give you an edge, especially if you’re racing against riders who haven’t upgraded their bikes yet. But once you’re up against riders with similar upgrades, the same basic rules of physics still apply: raw watts win. The bigger rider can usually push more power, and if the upgrades are equal, that inherent advantage isn’t erased.

The bigger rider can usually push more power, and if the upgrades are equal, they don’t erase that advantage.

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