Yes, titanium bikes can be fast, but not for the reasons most people expect. A titanium frame won't beat a top-end carbon race bike on a scales-and-wind-tunnel comparison. Where it wins is in how well you can ride it for hours, and modern titanium has closed much of the gap.
Titanium vs carbon: weight
Weight is the usual objection, and it's a fair one. Reilly's own team says metal bikes will always be heavier than carbon, and that the brand prefers to focus on ride quality rather than the scales. The Reilly Fusion road bike has a claimed frame weight of 1.7kg and a claimed 8.2kg build weight in size large with Dura-Ace.
For most riders, that weight difference is small next to the effect of tyres, fitness and position.
Stiffness and power transfer
Titanium has a reputation as a soft, springy material. Modern titanium bikes are more nuanced. Stiffness depends on tube shape, diameter and alloy as much as material.
Aerodynamics
Aero used to be carbon territory. Reilly's Fusion uses investment casting to make carbon-like tube shapes, and its kamm-tail profiles are designed to rival the carbon frames that dominate the aero category. A titanium bike can now look and behave much more like a modern race bike.
Comfort is where titanium gets faster
Speed over a long ride depends on how you feel at hour five, not just hour one. Reilly boast that titanium brings all-day comfort, and that anyone spending hours or days in the saddle will find it more comfortable than carbon. A comfortable rider holds power for longer, keeps a better position and recovers faster, which is why titanium suits sportives, audaxes and multi-day events.
Reilly's range: which titanium bike is fastest?
Road
Fusion (aero road): The most race-oriented Reilly. It combines classic race geometry with aerodynamic hydroformed titanium tubes.
T325D : Reilly's more traditional titanium road bikes, sitting alongside the Fusion in the range.
Spectre (all-road): Built for speed, comfort and versatility, with big tyre clearance and mudguard mounts for year-round riding. It's a good pick for fast riding on imperfect roads.
Gradient: The do-everything gravel bike. It has 47mm tyre clearance.
Reflex (gravel race): Reilly describes it as more race-focused and responsive than the Gradient, with a stiffer bottom bracket but the same geometry, and the biggest tyre clearance in the range. It's the fastest option off-road and perfect for gravel racing.
Tyres matter more than frame material
On gravel especially, tyre choice changes speed more than frame material. Fit fast-rolling tyres to a Gradient or Spectre and you'll notice the difference immediately. Wider, lower-pressure tyres are also faster on rough surfaces because they absorb bumps rather than bouncing off them, and this is where titanium's compliance helps.
Durability: speed you can keep
A titanium frame doesn't corrode, and it should hold up to years of hard use. Reilly backs its frames with a lifetime frame warranty for the original owner. If you'd otherwise replace a carbon frame every few years, you can spread the cost of a titanium bike over a much longer period.
To sum up, are titanium bikes fast?
Faster than a carbon bike in a wind tunnel? Probably not.
Fast enough to win races and sportives? Absolutely yes.
Fast over long distances? A BIG yes.
Fast off-road? Yes especially with wide tyres.
Is titanium faster than aluminium? Titanium is typically more comfortable and durable, and can be similarly stiff. Reviewers describe the difference in ride quality as significant.
Is titanium faster than steel? Broadly, titanium is around half the weight of chromoly steel, with similar strength and springiness.
What's the fastest titanium bike? For road, Reilly's Fusion. For gravel, the Reflex.
Can a titanium bike be aero? Yes. Casting and hydroforming allow carbon-like tube shapes.