7s, 8s, 9s, 21s, 24s & 27s: Which Bicycle Gears to Choose?
OMO BikesShare
The biggest difference between Ace, Prime, Pro and CUES is the gear system.
As you move up, you get:
- Smoother shifting
- Better quality components
- Higher durability
- Lower maintenance
- Better riding experience
Quick Comparison
| Gear System | Best For | Main Advantage |
|---|---|---|
| 🟢 Ace (7/21) | Beginners & casual riders | Best value |
| 🔵 Prime (8/24) | Regular fitness riders | Better shifting |
| 🟠 Pro (9/27) | Enthusiasts & long rides | Premium performance |
| ⭐ CUES (9/18) | Heavy daily use & touring | Maximum durability |
What Changes as You Upgrade?
| Groupset | Climb | Speed | Shifting | Durability | Maintenance |
|---|---|---|---|---|---|
| 🟢 Ace | ★★★☆☆ | ★★★☆☆ | ★★☆☆☆ | ★★☆☆☆ | ★★☆☆☆ |
| 🔵 Prime | ★★★★☆ | ★★★★★ | ★★★★☆ | ★★★☆☆ | ★★★☆☆ |
| 🟠 Pro | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★☆ |
| ⭐ CUES | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★★ |
★ Ratings compare OMO Bikes groupsets only.
🟢 Ace (7/21 Speed)
Ideal For
- First bicycle
- Casual riding
- Budget-conscious buyers
Highlights
- Shimano Tourney drivetrain
- Steel crank
- Entry-level hubs
- Reliable & affordable
Gear Range
7-Speed — 42T × 14–28T Freewheel
Gear Ratio: 1.50–3.00
21-Speed — 24/34/42T × 14–28T Freewheel
Gear Ratio: 0.86–3.00
🔵 Prime (8/24 Speed)
Ideal For
- Regular riders
- Fitness rides
- Weekend rides
Upgrades over Ace
- Cassette instead of freewheel
- Better hubs
- Alloy crank
- Shimano Acera rear derailleur
- Smoother shifting
Gear Range (typical)
8-Speed — 42T × 11–30T Cassette
Gear Ratio: 1.40–3.82
24-Speed — 24/34/42T × 11–30T Cassette
Gear Ratio: 0.80–3.82
🟠 Pro (9/27 Speed)
Ideal For
- Enthusiasts
- Long-distance cycling
- Premium riding
Upgrades over Prime
- 9-speed drivetrain
- Altus / Alivio derailleurs
- Higher-end shifters
- More refined shifting
Gear Range (typical)
9-Speed — 42T × 11–30T Cassette
Gear Ratio: 1.40–3.82
27-Speed — 24/34/42T × 11–30T Cassette
Gear Ratio: 0.80–3.82
⭐ CUES (9/18 Speed)
Ideal For
- Daily riders
- Touring
- Heavy usage
Upgrades over Pro
- Complete Shimano CUES drivetrain
- LINKGLIDE technology
- Stronger cassette
- Longest component life
Gear Range
9-Speed — 40T × 11–36T Cassette
Gear Ratio: 1.11–3.64
18-Speed — 22/40T × 11–36T Cassette
Gear Ratio: 0.61–3.64
Which One Should You Buy?
| If you... | Choose |
|---|---|
| Ride occasionally | ✅ Ace |
| Ride several times a week | ✅ Prime |
| Want smoother, premium performance | ✅ Pro |
| Ride very frequently | ✅ CUES |
A Simple Way to Think About It
🟢 Ace → Best value for most riders.
🔵 Prime → Best balance of price and performance.
🟠 Pro → Better shifting and a more refined ride.
⭐ CUES → Built to last the longest with Shimano's latest drivetrain technology.