Originally Posted by
Bryan C.
Sure wider tires and a suspension fork are indeed more comfortable, but certainly less efficient and in my opinion would ruin the over feel of a gravel bike. There are much better options in the MTB world these days. My current generation Stumpjumper climbs and descends better than my Diverge, and is way more comfortable on single track and even the cattle scarred trails that are local to me.
All forks are suspension forks in some sense. They can flex more than you might appreciate. Suspension fork like this put the flex under control and in the correct direction. And funny thing, that means you can run a
smaller tire, a point SRAM makes in their ad copy. For a lot of conditions a suspension fork
adds efficiency, in the same way as somewhat larger tires - at least compared to the overbuilt stiff-as-glass disc forks on nearly all gravel bikes, that nearly require a huge tire just to ride comfortably. And the comfort makes long rides less painful, for the same output. The other way to get this kind of travel is with premium thin-wall steel. But both tires and even flexy rigid forks provide nearly no damping, still relying on the rider's jiggling corpus.
I have not been able to find anything about how many watts a suspension fork loses in riding conditions, except some thoughtful but full-system level projects from Jan Heinie that showed it working pretty well. I've looked! Maybe if I got really bored I could go look up someone's dyno chart for a Charger race day damper and then see if anyone has made a travel histogram for a gravel race. But I rather doubt I'll find it. Most real suspension work is devoted to long travel racing bikes (like EWS) and they concentrate on reducing fatigue and improving feel.