|Recent race bike design is starting to acknowledge that stiffness everywhere in a bike isn't necessarily a good thing.|
Those bikes specifically designed for that niche of riding have peculiar traits which have been honed over decades of design and with material technologies available now, they are typically very stiff bikes. They should be. Cyclo cross is a short event which demands racers have every iota of energy come out as power to the ground. Stiffness to the detriment of comfort is something which is a given in this sport of cyclo cross, which, let's be honest, is about suffering on many levels.
Anyway, the point is that cyclo cross bikes are not tuned to absorb the sort of vibrations that gravel road riding induces. This makes them not the best tool for the job. NOTE- I did not say that you should never use a CX bike for gravel. I merely am saying that these sharply defined bikes for a singular purpose are not really "gravel bikes". And I haven't even mentioned their geometry, which also isn't ideal.
But that isn't a big deal anymore, like it was five or more years ago. Now you can buy a bicycle tuned for gravel travel from many brands, and some of those actually address the problem of vibration by allowing flex.
|Salsa Cycles Warbird was designed to absorb vibrations over gravel roads.|
Obviously, stiffness isn't always the over-arching goal of design, but typically we see riders responding to claims of stiffness in a frame as being "good". Not just in terms of bottom bracket stiffness, or lateral stiffness, but in the entire frame. Customers think this is "good" in a frame, and they can feel this stiffness, so it must be "good".
Carbon frames have also made a name for themselves by being brutishly stiff, yet having the oft misused descriptor of "carbon absorbs vibrations" attached to them by unwitting salespeople and general riders. This may have been the case 25 years ago when carbon fiber frames were not as well made, (read: having more bonding component compared to actual carbon material), but that is not the case anymore. Carbon stiffness is incredible now days, and vibrations are not muted by the material. It just passes through frequencies and energy differently than metal frames, but the energy is still getting through to the rider.
|One place where carbon has made ride quality worse than ever is in the area of forks.|
One of my pet peeves is the use of carbon forks with massive, thick legs, tapered steer tubes, and thick "uni-crown" style fork crowns. These forks do not give an inch. (Again- riders can feel stiffness and think it means "I'm faster", but they aren't) These unforgiving forks may make sense to a cyclo cross racer, where high load cornering is almost always a thing. But for the general public, and especially for gravel riders, it is a useless commodity. Forks which flex and give are far more road worthy and comfortable. Straight steer tubes, while seemingly archaic, actually allow some flex which also helps keep the front triangle, and especially the handle bars, "quieter". Less vibration means more comfort and a faster ride. Think about this. Why would Specialized and Trek work so hard to design flex into the front ends of their bikes?
But flex, and the resulting smoother and more efficient ride quality, is a hard sell. Riders feel smoothness as "slowness". This was true back when suspension forks came along for mountain biking in the early 1990's. Riders tried it and hated it, saying the devices made them slower and sluggish. However; when running similar courses back to back with suspended and non-suspended bikes, it became clear that the smoother riding suspension equipped bikes were making for faster times. All that despite these bikes being heavier and "less stiff" than their non-suspended counterparts. Well, we know what happened next......
Why is it so hard for us to understand that flex, be it passive or active, as in suspension applications, make us faster and obviously more comfortable when almost any other human carrying vehicle employs suspension and flex? Vibrations are bad, most often, and as cyclists, we should be very wary of any bicycle company claiming that more stiffness is a good thing.