Precious metal

What's the trail truth behind titanium frames?

If you were mountain biking a decade or so ago, you'll probably remember when titanium was the material of choice for bike manufacturers' flagship rides. Since the mid '90s, though, the rise of full suspension has pushed titanium hardtails off the top of the podium. The development of alloy and carbon fibre technologies has also created new challenges to titanium's previously unquestioned hardtail supremacy.

That said, titanium (often referred to by its chemical symbol Ti) has always maintained a loyal following from those who value a more supple, subtle ride, and are prepared to invest the extra money over steel frames to get it delivered in a lighter and potentially lifetime-lasting format.

Manufacturers are responding to the latest technical and equipment demands by updating classic high-class designs or creating entirely new ones. Cutting-edge manufacturing techniques at the top end, and lower-cost Far Eastern-produced frames relying on titanium's natural properties, are also creating more interest in titanium bikes.

If you still can't find exactly what you want, then the price of full custom frame designs has come down dramatically, too. This means that not only the super rich can have their perfect frame dreams made reality – as long as you're patient enough to wait a while for delivery. So how much do you need to spend, and what do you need to know to get the best from this magical metal?

Why choose titanium?

Titanium has always been renowned for creating very special bikes. In fact, what's kept titanium alive is exactly that – a reputation for a 'life' in its tubes that no other material can match.

As an extremely strong metal – made stronger and more malleable by alloying with elements such as vanadium – you need much less titanium than any other material to make a tough frame. That means titanium frames are always impressively light, even those which are impressively strong.

The reduction in necessary material lends itself to thinner, skinnier tubes that enhance the already highly resilient 'sprung' characteristics of titanium's elastic strength. Even large tubes respond much more dynamically to trail loads and impacts than aluminium alloy tubes of the same diameter.

This resilience translates to potentially very long fatigue lives for titanium frames, a lifespan backed up by the material's extreme resistance to any sort of corrosion.

What's more, even basic titanium bikes still have enough of the characteristics of their more expensive brethren to be something special. Compare that with the horrible ride you'll get from a really cheap steel or alloy frame, and you'll see why titanium's reputation has stayed intact for more than two decades.

Too good to be true?

That's not to say you can't make a bad titanium bike. Recent developmental advances in top end tubing have enabled bike makers to push titanium performance even further, but that's not always a great thing. Some of the highly worked frames we've ridden have actually been pushed too far and lost the whole 'zing' spring of classic titanium.

Other frames have skimped on design, material or both in crucial areas, which can lead to cracking and frame failure. In fact, despite titanium's inherent strength, we've probably seen proportionally more torn or trashed titanium frames in our test careers than any other material – with the exception perhaps of lightweight steel.

Even in its raw form, titanium is an expensive material. It's also time-consuming and awkward to work with, which increases the finished unit. While it doesn't corrode, it has a nasty habit of microscopic particles 'galling' against the surface of other threaded components. This can effectively seize them in place permanently, unless you use a copper-based 'titanium prep' compound on all threads prior to assembly.

Designing a bike for life

If you're paying a premium for a material that offers a very long frame life, it makes sense to get a bike that's as future-proof as possible. There are two ways of addressing this issue.

The first is to stay with a classic, 100mm fork-ready, lightweight 'race style' rig. This format hasn't changed in years, despite the appearance of ever lighter and more capable suspension forks and disc brakes. That's simply because it's the best sort of bike for getting from A-B or start line to finish line as fast as possible. The fact that titanium can add subtle comfort and increased traction control without incurring a weight penalty means it'll always shine in this format, too.

The other option is to make as modern a bike as possible, using the latest lightweight mid-travel forks and lightweight large-volume tyre to create a tenacious titanium trail tamer. While optimum fork length for this category seems to have settled at around 120-140mm, there's still a lot of different opinions about exactly what shape and feel the rest of the bike should have – as evidenced by our test examples from Cotic, Cove and the up-market Seven.

Fantas-Ti-c

One thing they all have in common is that we've loved riding all of them, despite all the different nuances placed onto the raw material baseline. So while different riders might choose a very different favourite from our foursome, you can be sure that's there's definitely still a lot of life in titanium hardtails.

Need to know

Understand the lingo of titanium with our essential jargon-busting guide

  • 3Al/2.5V — Titanium alloy with a 3 percent aluminium and 2.5 percent vanadium. Not quite as strong as 6Al/4V (below), but easier to work - especially to make into tubes - and therefore cheaper for you to buy. This metal is used for the majority of titanium tubesets and components on the market.
  • 6Al/4V — This is an extremely strong titanium alloy with a 6 percent aluminium and 4 percent vanadium. Unfortunately, it is very hard to work, which makes it expensive to use as a frame material. Normally restricted to small parts on more expensive frames, such as the dropouts.
  • Butting — Variations in wall thickness of tubes to keep strength where it's needed at the ends, but keep them thin and light in the middle where there's less stress. Double butted tubes change thickness at either end, single butted just at one end.
  • Cowled — Dropouts with a rounded shroud over the top like a mudguard. Looks nice, adds some stiffness and gives a straight surface for the stays to weld on to.
  • Gusset — Extra plate welded on to the outside of tube junctions to spread stress.
  • Laser cut — The high-tech way to get accurate shapes out of metal plate without causing any extra saw-related stress.
  • S bend — Lazy 'S' shape that's used on both chainstays and seatstays to give some extra clearance around the tyre (outwards) and also in the heel/ crank rotation area (inwards).
  • Swaging — Usually refers to a change in the external diameter of a tube; in general, a method of changing the shape of a piece of metal by squeezing it in a die.

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