Which frame and fork material really is king regarding sheer overall comfort? I am looking for an 80-mile-a-day, long-hauler with relaxed frame geometry. Also, what wheel and tire combination is best for all-day riding.
Your three best choices (assuming the builders are top notch) are steel, carbon or titanium. The advantage of carbon and titanium is the corrosion-proof nature of the materials. Aluminum can be made to ride comfortably, but it is not the first choice.
As for tires, 23 or 25-millimeter tubulars give the best and most comfortable ride. Hutchinson tubeless tires are my next and best choice for comfortable riding clinchers. Schwalbe Ultremo 25-millimeter clinchers and Vittoria's open-tubulars are also pretty darn smooth-riding clinchers.
So Does Frame Material Really Matter?
I agree with the comments and selection of tires. You mentioned frame materials, but never went into any explanation about their impact on bike comfort. Personally, and I believe a lot of "experts" would agree, frame material has probably become a very minor factor in the comfort equation. Regardless of material, most frames have very little flex. The majority of a bike's comfort comes from the wheels/tires and the saddle. Maybe a little comes from the seatpost.
For the most part, you are correct: tire and wheel selection play a huge part in the comfort and quality of the ride. Handlebar choice is another big one, as bars flex considerably.
Ride quality and frame stiffness are only loosely related. Rigid frames can deliver a smooth ride, and flexible frames can rattle your teeth out. Frame design and material choice play an important role in the feel and ride quality of the bike.
Here's the long version:
Frame materials can make a difference—more so than one may imagine, because flex is usually measured with static pressure (the frame is captured at the hubs or bottom bracket, and a measured amount of force is introduced at some point while a device measures frame deflection).
Sharp impacts—like those generated by smacking a pothole—can and do flex a rigid frame quite easily. The way a frame is constructed—choice of material, length of head tube, diameter and thicknesses of the frame members, and where the geometry of the frame places the rider's mass in relationship to the acceleration vectors generated by the impact—make a huge difference in comfort, regardless of the lateral stiffness of the frame.
Imagine a small earthquake sending a ripple through the fork, then into the frame and up to the saddle—thousands of times over the course of a ride. Small changes in frame design and material thickness can play a major role in how the signal-wave of a sharp impact transfers energy to the rider. This is why some carbon frames ride comfortably, yet feel super stiff under power.
My BH G4 rattled my teeth out over rough pavement until I switched its Mavic R-SYS clincher wheels with Zipp 202 tubulars. The difference in the ride was night and day. That said, its lateral rigidity was not affected—it remains slightly flexible under out-of-the-saddle efforts.
The new BH G5 is immensely more rigid under power, and yet it rides noticeably smoother over rough pavement. The G5 has slightly different geometry and a completely different tube profile and carbon layup.
Carbon, titanium, steel, aluminum and bamboo all transmit low- and high-frequency signals differently. Without suspension, the road bike's frame can transmit shock waves directly to the rider, so the choice of material will color that feeling in a noticeable way. The designer is in charge of getting the mixture of material, geometry and tube profile right, and given the same components, that's what makes a bike feel like a hero or a zero.
The Short Version
So, frame material and stiffness are two of four factors that determine ride quality. Frame design and component choice are equal players in the equation.
Contact Richard Cunningham for questions or comments, or just to talk bikes at: askRC@roadbikeaction.com.
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