The title is from a comment at the end of the video. He doesn’t really believe so, but the results can make one wonder.
It depends what you’re looking for. Since being faster isn’t necessarily anyone’s only goal. But it’s not just speed since the XC is going to be the more capable climber, and confident descender on steep gravel. Which is something I value.
Anyway, I only watched the start and the end since it’s a long video.
They are for different purposes. A gravel bike for me is a gravel roadie. Gravel roads and paths. Different routes with less traffic. My gravel bike has basically the same fit as my roadies. A MTB would be less practical.
I do not see the point of a flat bar roadie for my riding purposes. Less hand positions, more drag and no real positives for my use. People have different uses and perspectives though.
So what would be the difference between a Gravel bike and a cyclocross bike. A mate in Newcastle gave me a lend of his Cyclocross bike about 11 years ago and I quite liked it…he did a few competition cyclocross events with it and done well, he’s the same age as I am and at the time that would have been around 55yrs or something like that. He road that bike on some of the Tour-de france sections on it as well as the steepest street in Dunedin NZ with same bike and beat the climb.
So are they the same bike type or are there subtle differences?
Cheers
brumby33
Pretty similar. Tyre widths are more restrictive in CX, so expect less ability to fit wider tyres. Gravel bikes are around with the ability to run 57mm WAM tyres. That will be far less common on CX bikes.
I don’t mind the flat bars and as far as restricted hand positions go, you can put those plug in bars on for added changes in hand positions. I change my hand position on the flat bar easily and as far as aero is concerned, well put a negative degree stem on so that it drops the bar height. 
Foo
Multiple hand positions with drop bars with brake hoods fitted. I like the drops too and spend a bit of time in them on rides.
Yeah the bar end things would be handy on flat bars I guess. Tt bars slapped on would be better. 
Geo on a CX bike is more road bike like. As WH indicated, the UCI tyre width spec is 33mm max, so don’t expect too much more tyre clearance than for that. Gravel bikes typically have slacker geo and wider tyres. But most tyres are still in the 40s at the moment.
I have ridden aa grand total of 1 gravel bikes. My '21 Revolt. It probably is a bit slower steering. I’d prefer my roadies were also slower steering tbh. I don’t need a fast steering bike. I will never race a crit ever again.
Plenty of 50+mm clearance gravellos coming out now;
Chat GPT did me a list of the relative trails of some bike types.
My Kona Unit X’s trail is 98 which puts it in downcountry or just into the trail class, even though it’s an XC bike by classification. It certainly can feel like a trail bike on very slow climbing with ponderously slow steering. However very stable downhill on gravel. Even with its 40mm stem and 62cm handlebar.
In contrast my Avanti rigid ATB has a trail of 72 which is in the modern gravel bike range. It steers well on steep climbs and feels quick and natural with most riding. So the ideal ATB/gravel bike in many ways. It’s a bit nervous downhill on gravel. But it does have a 35mm stem and a 68cm handlebar.
Handlebar and stem combos on both bikes lend themselves to more quick steering.
As for tyres. For true gravel riding only, on an unsuspended gravel bike. I think a fast rolling 56mm is going to turn out to be the best width in the future. Gravel racing is starting to show this. I’ve tried narrower and wider tyres than 56 (2.2") but have found neither quicker on gravel. (Your gravel type and general use may vary.)
