Titanium has long been revered in the world of custom bike building for its unmatched blend of strength, weight, durability, and exceptional ride quality. But not all titanium is created equal.
If you’re considering investing in a titanium bike frame, it’s worth understanding the different grades of titanium tubing used in the cycling industry - because it directly affects performance, comfort, and longevity.
At Enigma Bicycle Works, we’ve specialised in titanium craftsmanship for nearly two decades. In this guide, we’ll break down the most commonly used grades, explain their differences, and highlight where they’re used across our titanium bikes and UK-made Signature range.
What Is a Titanium Grade?
Titanium is categorised into different "grades" based on its alloy composition and mechanical properties, as defined by ASTM (American Society for Testing and Materials). The most commonly used titanium grades in bicycle framebuilding are:
- Grade 9 (3Al/2.5V)
- Grade 5 (6Al/4V)
- Grade 2 (CP2 - Commercially Pure)
Each offers distinct characteristics that influence ride feel, frame weight, and how the bike handles.
Grade 9 Titanium – 3Al/2.5V: The Industry Favourite
Composition: 3% Aluminium, 2.5% Vanadium, 94.5% Titanium
Properties: Medium strength, excellent weldability, fatigue-resistant
Common Uses: Main triangle tubes, chainstays, seatstays
Often called the workhorse of titanium bike building, Grade 9 (3Al/2.5V) is the most commonly used alloy in the cycling industry. It offers the ideal balance of stiffness, compliance, and workability, making it the go-to choice for most performance titanium frames.
At Enigma, Grade 9 titanium is used extensively throughout our range, from models such as the Escape, Etape and Eremos to our UK-made Signature frames.
In addition to our proprietary Grade 9 tubing, we also build with Reynolds 3Al/2.5V titanium on selected models such as the Eikon and Esker. Reynolds tubing is known for its slightly thinner wall profiles and is marginally lighter, offering subtle weight savings and a smoother ride feel-particularly well suited to gravel and road builds where precision and compliance matter.
Explore our titanium road bikes and titanium gravel bikes to see how different tubing choices are applied across bikes designed for different styles of riding.
Grade 5 Titanium – 6Al/4V: The Elite Performance Alloy
Composition: 6% Aluminium, 4% Vanadium, 90% Titanium
Properties: High strength, less ductile, more difficult to form
Common Uses: Bottom bracket shells, head tubes, dropouts, premium performance frames
Grade 5 (6Al/4V) titanium offers roughly 50% more tensile strength than Grade 9. That makes it perfect for high-performance applications, particularly where stiffness and efficiency under load are critical. However, it's harder to work with and requires more advanced tooling and skill to fabricate.
At Enigma, we exclusively use Grade 5 (6Al/4V) titanium on our flagship model, the Excel. Its Grade 5 main triangle maximises power transfer and responsiveness, delivering an uncompromising ride for serious riders.
Grade 2 Titanium – Commercially Pure: Simple but Limited
Composition: ~99.2% pure titanium
Properties: Very ductile, corrosion-resistant, lower strength
Common Uses: Budget frames, accessories, small components
Grade 2 titanium (also called CP2) is a commercially pure variant known for its excellent corrosion resistance and ductility. It is easy to form compared with stronger titanium alloys but lacks the mechanical strength of Grade 9 or Grade 5. For this reason, Enigma does not use Grade 2 for its principal structural frame tubing, although commercially pure titanium can be suitable for certain accessories and components.
Summary Table: Comparing Titanium Grades for Bikes
| Titanium Grade | Composition | Strength | Weldability | Common Use |
|---|---|---|---|---|
| Grade 2 | Pure Titanium | Low | Excellent | Accessories, fittings, non-structural components |
| Grade 9 | 3Al/2.5V | Medium | Excellent | Main tubes, stays (industry fav) |
| Grade 5 | 6Al/4V | Very High | More difficult | Dropouts, BB shells, elite frames |
Why Titanium Grade Matters for Your Ride
Choosing the right titanium grade can transform the way your bike feels and performs. Grade 9 provides the all-day comfort and reliability ideal for most riders, while Grade 5 pushes the limits of weight savings and stiffness for those chasing marginal gains.
At Enigma, we tailor each model to make appropriate use of the material’s strengths-whether that’s a responsive titanium all-road bike or a fully bespoke custom titanium bike. Understanding these differences can help you choose the right frame for your riding style and goals.
Final Thoughts: Why Expertise Matters in Titanium Framebuilding
Working with titanium isn't easy-it takes experience, specialist tools and a deep understanding of the material. At Enigma, we've specialised in titanium bicycles for nearly 20 years, with our UK-made frames handcrafted in our Sussex workshop.
Whether you’re exploring your first titanium bike or looking for your next dream custom build, we’re here to guide you.
👉 Explore our full range of titanium bikes
📞 Get in touch with our team to talk through your build