Thinking outside the head tube
Rule 1.3.020 of the UCI technical guidelines specifies that no frame member shall have a depth greater than 8cm or a width narrower than 2.5cm, nor shall it exceed the aspect ratio of 3:1. This is our engineer’s challenge.
The head tube of our sleek DA frame was already pushing the limits with its NACA airfoil-shaped profile and narrow width housing a smaller 1” steerer tube. So what were Felt designers to do in their quest to produce the fastest bike in the world?
Get creative, which is exactly what we do best.
Thanks to countless hours in front of our computational fluid dynamics workstations and true wind tunnel development – not just after-the-fact testing - the combination of our Bayonet 2 fork and DA head tube yields an extra-slippery aspect ratio of 3:1 where it is most effective: right at the leading edge of the bike.
As a result, we were able to reduce total bike drag by a whopping 10% (roughly 80g) compared to a standard 1” aero-bladed fork, unequivocally making our DA the fastest UCI-legal time trial bike in the pro peloton.
We didn’t just set out to claim the aerodynamics prize, though. By moving the steerer tube outside of the narrow head tube, our designers were able to make it larger and stiffer for improved rigidity and handling responsiveness. In addition, the massive aero crown gives rise to extra-deep aero fork blades, again making for a dramatically stiffer overall package. In fact, the Bayonet 2 is a mind-blowing 60% stiffer than a usual 1” front end, making it even stiffer than a standard 1-1/8” steerer or even any of those new-fangled tapered designs, both of which are appreciably less aero as well.
So not only is the Bayonet 2 front end the most aerodynamic in the world, it’s also among the most precise handling, too.
Naturally, it wouldn’t make any sense to strap on a non-aero standard stem, so we’ve developed a clever adjustable stem system for our Bayonet 2 as well. We offer lengths from a stubby 90mm all the way to 145mm and everything in between, and each is also adjustable in angle from -20 degrees (from horizontal) to 105 degrees.
Installation of the Bayonet 2 system is no more complicated than a regular fork, making life easier for your favorite mechanic and ensuring that the familiar system will always be properly tuned. In the event of some sort of mishap, you could even sub a standard fork into the standard 1”-compatible head tube – though you’d be slower. Yes, we’ve thought of everything.
More aerodynamic. Stiffer. Sleeker. More adjustable.
One ride on our wind-splitting Bayonet 2-equipped DA is all you’ll need to convince yourself that it’s simply the fastest ride around.
Bayonet™ 2 - THE SUMMARY
• Bayonet™ is the best of all worlds: more aerodynamic than a standard 1-1/8” steerer, stiffer than even a tapered steerer, and faster than anything else in the world. Simply put, it’s the finest aero front end on the market.
• Free yourself from conventional constraints on how the front end of a bike should look and function and the result is the revised Bayonet™ 2 steering system. By moving the narrow 1” steerer tube outside of the head tube, our designers were able to build a system that is faster than anything else out there while sacrificing nothing in the process. The leading edge of the Bayonet™ 2 fork creates an especially slippery combined airfoil section in combination with the shielded head tube (decreasing complete bike drag by more than 10% in fact) and the external steerer in combination with especially deep fork legs is 60% stiffer than a conventional 1” front end for razor-sharp handling.