Single Speed Gear Ratio Charts
Having trouble picking out the right gear ratio for your single speed? Check out these charts to help you make the right decision. There’s a wee bit of science/math involved here. If you are a beginner to single speed mountain biking, 32/19 is a common starting point, but to get the best understanding we recommend you check out this video by our friend at DirtWire.tv
Basic Single Speed Gear Ratio Chart
| 28 | 30 | 32 | 33 | 34 | 36 | 39 | |
|---|---|---|---|---|---|---|---|
| 14 | 2.00 | 2.14 | 2.29 | 2.36 | 2.43 | 2.57 | 2.19 |
| 15 | 1.87 | 2.00 | 2.13 | 2.20 | 2.27 | 2.40 | 2.60 |
| 16 | 1.75 | 1.88 | 2.00 | 2.06 | 2.13 | 2.25 | 2.44 |
| 17 | 1.65 | 1.76 | 1.88 | 1.94 | 2.00 | 2.12 | 2.29 |
| 18 | 1.56 | 1.67 | 1.78 | 1.83 | 1.89 | 2.00 | 2.17 |
| 19 | 1.47 | 1.58 | 1.68 | 1.74 | 1.79 | 1.89 | 2.05 |
| 20 | 1.40 | 1.50 | 1.60 | 1.65 | 1.70 | 1.80 | 1.95 |
| 21 | 1.33 | 1.43 | 1.52 | 1.57 | 1.62 | 1.71 | 1.86 |
| 22 | 1.27 | 1.36 | 1.45 | 1.50 | 1.55 | 1.64 | 1.77 |
| 23 | 1.22 | 1.30 | 1.39 | 1.43 | 1.48 | 1.57 | 1.70 |
| 24 | 1.17 | 1.25 | 1.33 | 1.38 | 1.42 | 1.50 | 1.63 |
| 25 | 1.12 | 1.20 | 1.28 | 1.32 | 1.36 | 1.44 | 1.56 |
27.5 Gear Inches
| 28 | 30 | 32 | 33 | 34 | 36 | |
|---|---|---|---|---|---|---|
| 14 | 55.00 | 58.93 | 62.86 | 64.82 | 66.79 | 70.71 |
| 15 | 51.33 | 55.00 | 58.67 | 60.50 | 62.33 | 66.00 |
| 16 | 48.13 | 51.56 | 55.00 | 56.72 | 58.44 | 61.88 |
| 17 | 45.29 | 48.53 | 51.76 | 53.38 | 55.00 | 58.24 |
| 18 | 42.78 | 45.83 | 48.89 | 50.42 | 51.94 | 55.00 |
| 19 | 40.53 | 43.42 | 46.32 | 47.76 | 49.21 | 52.11 |
| 20 | 38.50 | 41.25 | 44.00 | 45.38 | 46.75 | 49.50 |
| 21 | 36.67 | 39.29 | 41.90 | 43.21 | 44.52 | 47.14 |
| 22 | 35.00 | 37.50 | 40.00 | 41.25 | 42.50 | 45.00 |
| 23 | 33.48 | 35.87 | 38.26 | 39.46 | 40.65 | 43.04 |
| 24 | 32.08 | 34.38 | 36.67 | 37.81 | 38.96 | 41.25 |
| 25 | 30.80 | 33.00 | 35.20 | 36.30 | 37.40 | 39.60 |
27.5+ Gear Inches
| 28 | 30 | 32 | 33 | 34 | 36 | |
|---|---|---|---|---|---|---|
| 14 | 57.00 | 61.07 | 65.14 | 67.18 | 69.21 | 73.29 |
| 15 | 53.20 | 57.00 | 60.80 | 62.70 | 64.60 | 68.40 |
| 16 | 49.88 | 53.44 | 57.00 | 58.78 | 60.56 | 64.13 |
| 17 | 46.94 | 50.29 | 53.65 | 55.32 | 57.00 | 60.35 |
| 18 | 44.33 | 47.50 | 50.67 | 52.25 | 53.83 | 57.00 |
| 19 | 42.00 | 45.00 | 48.00 | 49.50 | 51.00 | 54.00 |
| 20 | 39.90 | 42.75 | 45.60 | 47.03 | 48.45 | 51.30 |
| 21 | 38.00 | 40.71 | 43.43 | 44.79 | 46.14 | 48.86 |
| 22 | 36.27 | 38.86 | 41.45 | 42.75 | 44.05 | 46.64 |
| 23 | 34.70 | 37.17 | 39.65 | 40.89 | 42.13 | 44.61 |
| 24 | 33.25 | 35.63 | 38.00 | 39.19 | 40.38 | 42.75 |
| 25 | 31.92 | 34.20 | 36.48 | 37.62 | 38.76 | 41.04 |
29 Gear Inches
| 28 | 30 | 32 | 33 | 34 | 36 | |
|---|---|---|---|---|---|---|
| 14 | 58.00 | 62.14 | 66.29 | 68.36 | 70.43 | 74.57 |
| 15 | 54.13 | 58.00 | 61.87 | 63.80 | 65.73 | 69.60 |
| 16 | 50.75 | 54.38 | 58.00 | 59.81 | 61.63 | 65.25 |
| 17 | 47.76 | 51.18 | 54.59 | 56.29 | 58.00 | 61.41 |
| 18 | 45.11 | 48.33 | 51.56 | 53.17 | 54.78 | 58.00 |
| 19 | 42.74 | 45.79 | 48.84 | 50.37 | 51.89 | 54.95 |
| 20 | 40.60 | 43.50 | 46.40 | 47.85 | 49.30 | 52.20 |
| 21 | 38.67 | 41.43 | 44.19 | 45.57 | 46.95 | 49.71 |
| 22 | 36.91 | 39.55 | 42.18 | 43.50 | 44.82 | 47.45 |
| 23 | 35.30 | 37.83 | 40.35 | 41.61 | 42.87 | 45.39 |
| 24 | 33.83 | 36.25 | 38.67 | 39.88 | 41.08 | 43.50 |
| 25 | 32.48 | 34.80 | 37.12 | 38.28 | 39.44 | 41.76 |
Understanding Gear Ratio vs. Gear Inches: The Foundation of Single Speed Performance
When you ride a single speed, simplicity is everything. No derailleurs, no shifters, no extra cables — just the raw connection between your legs and the rear wheel. But beneath that simplicity lies one of the most important decisions a single speed rider can make: choosing the right gearing.
At Endless Bike Co., we’ve been obsessed with single speed perfection since day one. Our precision-machined cogs, designed and manufactured right here in Western North Carolina, are built for riders who appreciate clean design, tight tolerances, and a gear setup that feels just right — whether you’re grinding up Pisgah climbs or flying down your local flow trail.
To dial in that “just right” setup, it’s crucial to understand two key concepts that often get mixed up: gear ratio and gear inches.
Let’s break them down and show how both work together to define your single speed experience.
Gear Ratio: The Mechanical Connection
At its most basic level, gear ratio is the relationship between the number of teeth on your front chainring and the number of teeth on your rear cog.
Formula: Gear Ratio=Front Chainring TeethRear Cog Teeth\text{Gear Ratio} = \frac{\text{Front Chainring Teeth}}{\text{Rear Cog Teeth}}Gear Ratio=Rear Cog TeethFront Chainring Teeth
It’s a simple fraction, but the effect it has on your ride is massive.
For example:
- A 32-tooth chainring paired with a 16-tooth cog gives you a 2.0 gear ratio (32 ÷ 16 = 2.0).
- A 34-tooth chainring with an 18-tooth cog gives you 1.89.
That number represents how many times your rear wheel spins for every one crank revolution.
A higher gear ratio (like 2.5 or above) means:
- The rear wheel spins faster per pedal stroke.
- You’ll move faster on flat ground.
- It’s harder to start pedaling or climb steep grades.
A lower gear ratio (like 1.6 or below) means:
- Easier starts and better climbing.
- Slower top speed.
- More spin at higher cadence.
Gear ratio is the foundation of your drivetrain feel — it’s pure mechanical leverage. It doesn’t care about tire size, rim width, or terrain. But as most single speed riders know, the feel changes dramatically between a 27.5″, 27.5+, and 29″ setup even with the same ratio. That’s where gear inches come in.
Gear Inches: The Real-World Translation
While gear ratio tells you the mechanical relationship between the chainring and cog, gear inches translate that relationship into how far your bike actually travels with each pedal revolution.
Formula: Gear Inches=Gear Ratio×Wheel Diameter (in inches)\text{Gear Inches} = \text{Gear Ratio} \times \text{Wheel Diameter (in inches)}Gear Inches=Gear Ratio×Wheel Diameter (in inches)
Let’s use that same 32/16 example again:
- Gear Ratio = 2.0
- On a 27.5″ wheel: 2.0 × 27.5 = 55 gear inches
- On a 29″ wheel: 2.0 × 29 = 58 gear inches
That means every time you crank a full pedal revolution, the bike moves forward roughly the distance of a 55-inch-diameter wheel roll (on a 27.5″), or a 58-inch-diameter roll (on a 29″).
The larger the gear inches, the farther you travel per pedal stroke — and the harder it feels to start turning that crank from a stop. Smaller gear inches feel lighter on the legs, great for climbing or technical trail riding.
Why Both Matter
The combination of gear ratio and wheel size (gear inches) determines how your bike behaves on the trail.
Imagine two riders:
- Rider A runs a 32/18 setup on a 29er.
- Rider B runs a 32/16 setup on a 27.5″.
Both have nearly the same gear inches — around 51-55 — which means they’ll experience a similar balance of climbing ease and cruising speed, despite different chainring/cog pairings.
That’s why many single speed riders talk in terms of gear inches rather than raw ratios. It’s a universal way to compare gearing across wheel sizes.
Still, for quick mental math on the trail, gear ratio gives an instant snapshot of your drivetrain’s feel. Gear inches simply refine it with wheel size factored in.
Finding Your Ideal Single Speed Setup
Every rider’s perfect gearing depends on terrain, wheel size, leg strength, and riding style. But here’s a general guide:
| Terrain Type | Common Gear Ratio | Typical Gear Inches (29″) | Feel |
|---|---|---|---|
| Steep / Technical Trails | 1.6 – 1.8 | 46 – 52 | Easier climbing, more spin |
| Rolling XC Terrain | 1.9 – 2.1 | 55 – 60 | Balanced all-around setup |
| Fast / Smooth Trails | 2.2 – 2.5 | 62 – 70 | Harder start, faster cruising |
For example, Pisgah’s rooty climbs and punchy terrain often feel best around 32/20 (1.6) on a 29er or 32/18 (1.78) on a 27.5+. That setup keeps your cadence up without blowing up your knees halfway through a climb.
If you’re racing smoother XC or flow trails, you might prefer 34/18 (1.89) or even 36/18 (2.0) for more momentum and higher top speed.
Why American-Made Cogs Make a Difference
Choosing the right ratio only matters if your components can handle the miles. That’s where Endless Bike Co. shines.
Our single speed cogs are precision-machined from aircraft-grade aluminum and stainless steel right here in Western North Carolina — no overseas shortcuts, no compromise on material or finish.
Each cog is:
- CNC-cut for perfect tooth alignment, ensuring smooth chain engagement and longer drivetrain life.
- Anodized for corrosion resistance and vibrant color options that won’t fade.
- Designed with wide bases to protect freehub bodies and eliminate gouging under torque.
- Crafted with American pride, supporting local machinists and small-batch quality control.
When you run a single speed, every detail matters. Chainline, cog thickness, and machining tolerance can make the difference between a quiet, efficient drivetrain and one that skips, grinds, or wears prematurely.
At Endless Bike Co., our goal is to keep your drivetrain dialed and durable — so the only thing you think about on your next ride is your line, not your gear teeth.
How to Use a Gear Ratio Chart
Gear ratio charts (like the one at the top of this post) are handy tools for comparing different setups. Here’s how to read one:
- Find your chainring size across the top.
- Find your rear cog size down the left column.
- The intersection gives you your gear ratio.
- Multiply that by your wheel diameter (27.5, 27.5+, or 29) to find your gear inches.
For example:
- 32T chainring and 16T cog = 2.00 ratio.
- On a 27.5″ wheel: 2.00 × 27.5 = 55 gear inches.
- On a 29″ wheel: 2.00 × 29 = 58 gear inches.
That 3-inch difference in wheel size adds a noticeable change in feel. On the trail, it’s the difference between spinning comfortably on a climb or grinding through with more torque.
Dialing in the Perfect Balance
Here’s the art of single speed riding: finding that sweet spot where you can both climb efficiently and maintain speed on flats.
Because single speeds lack the luxury of shifting, your chosen ratio becomes the soul of the bike. Too low, and you’ll spin out on descents. Too high, and you’ll stall on technical climbs.
Many riders keep two or three Endless Bike Co. single speed cogs in rotation — one for local trails, one for race setups, and one for big-mountain trips. Swapping between a 17T, 18T, or 20T cog can completely change the personality of your bike, even with the same chainring up front.
Our precise tolerances make cog changes fast and secure — no wobbles, no shims, no uneven wear. Just clean engagement every time.
Real-World Example: 27.5 vs. 29
Let’s compare two popular setups that use the same gear ratio:
- Setup A: 32/16 on 27.5″ = 2.00 ratio, 55 gear inches
- Setup B: 32/16 on 29″ = 2.00 ratio, 58 gear inches
On paper, both have identical ratios, but the 29er covers more ground per pedal stroke. That translates to a slightly harder start and faster cruising speed.
Now, swap that same 32T chainring for an 18T cog on the 29er:
32 ÷ 18 = 1.78 × 29 = 51.6 gear inches — a perfect balance for climbing and technical trail work.
It’s all about finding your rhythm — and once you’ve got it, you’ll feel the efficiency and simplicity that make single speeding so addictive.
Keep It Simple, Keep It Precise
Gear ratio tells you how your drivetrain multiplies your pedaling force.
Gear inches tell you how far your bike travels per revolution.
Together, they define your single speed’s personality — how it climbs, how it accelerates, and how it feels when you’re in the flow.
At Endless Bike Co., we believe that simplicity and precision aren’t opposites — they’re partners. That’s why our American-made single speed cogs are engineered to make your gearing decisions easy, your rides smoother, and your drivetrain bulletproof.
Whether you’re fine-tuning your ratio for the next big climb or experimenting with different wheel sizes, start with the basics: understand gear ratio, calculate your gear inches, and trust your components.
Because when your setup is dialed, there’s nothing more pure than a single speed — one gear, one chain, endless ride.
Explore our full line of Endless Bike Co. single speed cogs — proudly made in Western North Carolina for riders who believe in quality, simplicity, and the joy of one gear.