Are wider tyres on performance road bikes really necessary for added comfort?

[maxim809]

I came across this video around bike comfort.
There are components to it I find interesting. Measuring vertical spring, how the "softest" spring is the key contributor to compliance; eg an exposed seatpost on a high pressure thin 23mm tyre or the wide low pressure tyre on a mountain bike.

But there are other findings I wonder about. The video suggests that frame material does not contribute towards comfort, but caveats that ride feel or quality is out of scope. Being comfort "vertical compliance" and not defining ride feel or quality of the different materials.

Fork is not mentioned, I think it plays an important role (particularly visible on gravel ones), I also thought a fair amount of flex comes through the stays.

Anyway, I think it is a interesting and well elaborated video and good food for thought.


https://youtu.be/Lb4ktAbmr_4

Thanks for the link. Was educational, and I believe the key takeaways.

Like yourself and some of the YT comments, I also wondered how the fork plays into comfort. In my experience, when I ride into the lip of a sidewalk curb ramp at speed (say, +20mph):

a. Steel Frame + Steel Fork = Incredibly jarring spike at the handlebars
b. Alu Frame + Carbon Fork = Fine
c. Carbon Frame + Carbon Fork = Also fine

Maybe I need to look at the handlebars, but my tape is all the same thin 2mm microtex and tires same too. I don't have any other bike configs to experiment with, but with my limited n=1 experience... it kinda points to the fork as the common denominator. Perhaps the fork is the front-of-bike reciprocal to the seat post. With that said, I know others swear by steel forks as being super smooth and compliant. So what gives, I wonder?

There's likely a reason why entry-level aluminum bikes from every major brand still comes equipped with carbon fork instead of going full metal. The only brand I can think of that does alu frame + alu fork is a $750 Raleigh Merit 1. I remember wanting to buy this years ago just to test out that aluminum fork...

Hope the guy does a follow-up to let us know if fork compliance is real or placebo.

[maxim809]

Dug into the comments a bit more and pulled out this from the guy who made the video...

The data we have suggests that there is little variance in vertical deflection of forks of differing materials, in fact, the steel fork in one study was the harshest. This doesn't mean all steel forks are harsh, of course - I've had multiple steel forks with noticeable vertical deflection. But it does suggest that you cannot buy any old steel fork and expect a higher vertical deflection than aluminium or carbon - you've got to be selective.

Hmmmm.

[DHG01]

Dug into the comments a bit more and pulled out this from the guy who made the video...

The data we have suggests that there is little variance in vertical deflection of forks of differing materials, in fact, the steel fork in one study was the harshest. This doesn't mean all steel forks are harsh, of course - I've had multiple steel forks with noticeable vertical deflection. But it does suggest that you cannot buy any old steel fork and expect a higher vertical deflection than aluminium or carbon - you've got to be selective.

Hmmmm.

I have found some forks more compliant than others. When riding over gravel and ruts, I remember seeing a Paralane fork wobble longitudinally; same with the Ritchey. Much less with the BMC CX01.