I calculate. My calculations also don't match up with the manufacturers', so when I compare, I compare between my calculated values.

In theory I think you're probably right. But all that goes out the window when you add 40mm tires at 35psi. Someone posted recently about the impact of high volume, low psi tires and the vast majority of the vibration/impact reduction of a bike is found in the tires.

Ok

All quite interesting and something that I continue to watch from afar and wonder about. Coming from 80s steel road bikes with traditional tubing and having a gravel bike with steel OS tubing as well as a road bike with steel OS tubing, i see the 44mm head tubes and huge tubing of so many bikes and wonder at what point are the returns diminished. I get that aluminum tubes need to be larger than steel due to material difference, but current steel gravel frames with a huge front end(44mm head tube, gussets, etc) and the similar sized carbon and aluminum frames just seem like overkill. Given the amount of suspension now built into some frames(futureshock stem, isospeed frame, or various rear suspension mechanisms on the seat stay), it seems like frames are overly stiff to the point of needed suspension to then be designed in.

I am 235# and my OS steel frame gravel bike hasnt ever felt noodly. Even though it hasnt felt noodly, would a 44mm head tube and OOS tubing feel better? Or would it be too stiff? Thats something that would be frame and bike specific and would only be answered with extensive riding, which isnt realistic without buying the frame/bike.

My current steel frame design(still subject to change many more times, im sure) is a mix of OS and OOS tubing to hopefully make a slightly stiffer frame than what I have, which still being far smoother than what I would otherwise get if buying something already made.
An OS seat tube, head tube, and top tube matched with an OOS downtube. That downtube would hopefully help offset the oval chainstays i will use since oval bent stay will naturally flex laterally more than the round stays that are crimped on my current bike.
The only settle is that I will use a carbon fork with straight steerer so thatll limit me to a Woundup or Ritchey...and the Woundup has a longer steerer which i will need, so i guess ill go with that. At the same time, to get a different carbon fork would require a 44mm head tube and giant tapered steerer which is all probably more stiffness than I need.
I ride gravel solo and a 15mph average on a 30+ mile route is a really good day. I wont set records and wont ever snap cranks due to Herculean power. Pretty sure a front end and bottom bracket can eventually be too stiff for my benefit.


Anyways, interesting points you bring up. I didnt realize there is someone else who sees the tubing diameters of some frames right now and questions the claims of comfort.

Huh?.

First of all, a gravel bike will have a stack measurement thay sets up the handlebars up to 2 inches higher than a road bike for a more comfortable riding position on long day rides that are more common on gravel bikes. (more comfortable)

Second, Gravel bike frames are built to be stiff laterally, but have much more vertical compliance to absorb road vibration. (Take a back view if a Warbird for example) (more comfortable)

Third, Gravel bikes can accomodate tires up to 40 or more MM, while few road bikes can fit even 32mm (more comfortable)

Fourth, gravel bikes ALL are built for Disc brakes, and until recently almost all road bikes came with caliper brakes (Maybe not more comfortable, but certainly easier on your hands on a long decent)

Fifth, gravel bikes normally have a longer wheelbase and slacker head angle compared to a road bike. This adds to comfort and creates stability, where road bikes have shorter wheelbases and steerer head angles for quicker maneuverability. (more comfortable)

And sixth, gravel bike riding is cool and growing fast while road bikes are a dying category!

I hear you. A gravel bike would split the difference between a Cutthroad and a Tarmack.. A Cutthroat with the right tires wll work pretty well as a gravel bike though and save the expense of another steed.

Isn't road geometry with bigger tires basically just a CX bike? My Swiss Cross is essentially a Road Logic with a higher BB, longer chainstays, 10mm shorter reach, and a 1.5º more slack headtube. But the Cross will just fit a 38 in back, while the Road Logic will just fit a 30. I've absolutely zero complaints about the comfort of my Ritchey. It is unquestionably my "all roads" bike.

I just looked at the geometry for the Warroad in my size-- no thanks. That's way more relaxed and upright than what I like. That's long before I get to the bonkers pricetag. It's priced at least $1,500 over what it's worth.

Depends on what you mean by "CX Bike". CX used to mean a fairly specific set of properties e.g. 65mm BB drop and being in compliance with what the UCI allowed for racing (since CX is well a race), which of course was after CX specific rigs became a thing and people weren't just training offroad on their road bikes (using the wrong tool for the wrong purpose as a training aid)...nowadays it is very wishy-washy.

As opposed to "gravel bike" which has never really meant anything at any point. Whether OS tubing or not.

That is funny, I've found gravel bikes to be relatively compliant. But stiff carbon bikes of 10 years ago, or Aluminum bikes of 20 years ago may not be the best benchmark. ;-) Back in the day stiffness was where it was at.

These days bikes are more likely to be " "Laterally stiff and vertically compliant." To me, this means a stiff bottom bracket area that applies my power efficiently, but the fork, bars, seat stays, seat tube, seat stem can all be compliant, making the bike comfortable on the road.

Just with my bikes, my track and gravel bike have similar stiffness where it counts, and similar acceleration, but my track bike is a nightmare on anything less than velodrome smooth. I was shocked doing 20mph on some horrid washboard on my gravel bike with 32mm tires - and I was just cruising along without realizing how bad it was. None of my older bikes can do that.

I have some old bikes that really twist under power. I can see the crank arms and the bottom bracket twist, and if my tire is too big it will rub against the frame.

Disk brakes don't seem to be a friend of ride quality though. Those older forks with the J bend had suspension built into them. These days with straight blade forks, necessitated by the torque of disk brakes, require other creative solutions to get a little front end compliance in them.

I run a Surly Straggler steel disc brake fork, and it's great. My old KHS had a straight-blade CF fork with an aluminum steerer, and it was the very manifestation of the word rigid.

Seeing the fork flex under heavy braking is a little disconcerting the first few times. Sure does ride nice, though.

I heard somewhere Tom Ritchey doesn't believe in oversized/tapered head tubes for gravel bikes because it makes them too stiff.

#notAllGravelBikes

It's in that video above basically. Tom is so old school, it clouds his thinking. I love that guy. He makes me want to buy all of his bikes.

Yep, anything more compliant than my old '86 Cannondale and my old Scott Foil is compliant in my book. Those two bikes were shockingly rough. But, man, that Foil was a flipping rocketship.

Ah, I didn't see that video. Interesting comment about carbon forks needing to be overbuilt.

After reading a few of these comments, im curious to heat what you are riding right now?

Oh- and what was the 2OS frame you refer to?

He doesn't inspire a lot of confidence in carbon does he?

But all his forks are carbon!

https://us.ritcheylogic.com/us_en/bike/forks

All 6 forks are carbon, but they also all come in 1 1/8 steerer, and only 2 of the 6 even offer a tapered steerer option. Certainly seems to go with his view on headtube diameter.

They make a 1 1/4" tapered fork too. But not 1 1/2" as far as I know.

edit: I'm dumb, but I'm agreeing with you. I don't know if that was clear. It's been a long day.