Am I over thinking the BB Drop & Chainstay?
 

As my search for a new gravel bike continues I become more confused when it comes to geometry. I was able to drop by a local LBS that mainly sells Cannondale, I went in there to look at the Topstone Alloy 105, he has low stock so he wouldn't budge on price . He was, however, willing to knock $500 off a Topstone 105 Carbon which he had more inventory of. I did a bit more research on that bike and it turns out that there are significant differences in geometry when comparing it to the regular aluminum version. What sticks out the most is a BB Drop of 61 for the carbon vs 75 for the aluminium. Another significant difference was the shorter chainstay on the Carbon at 415 vs 430.

The other bikes that I'm looking at are the Checkpoint, Revolt and Diverge, all have BB Drops between 70 and 80 and their chainstays are between 425 and 430 similar to the aluminum Topstone. Seems to me that the Topstone Carbon sticks out when comparing it to the rest. I'm still a bit unclear as to how a short chainstay and low BB Drop affect the ride of a bike.

Does it make it more CX/Mountain Bikish? I'm looking for a gravel that leans more road then trails, would this be a good bike or a bad choice? I imagine it would be nice to have carbon and a bit of suspension with the Kingpin technology.

Thank you for any opinions on this matter.

I think the thought is that a bike with more bb drop will handle better. Partly because your seat will be lower and therefore your CG will be lower.

If you are going to use the old toe clips, you might want a bike with less bb drop. Otherwise, unless you have lot of roots and stumps you got to avoid or have hellatiously long cranks, it's probably not a big deal.

Have a look at the latest version 3T Exploro. That is a pretty good example of frame dimensions which leans toward road.

You would want something with a shorter chainstay (415-420mm) for a gravel bike. Makes the rear end quicker to maneuver.

I'd say bb drop around 75mm or a little more, to keep you 'in' the bike.

The carbon Checkpoint is pretty suitable in my view for a mid-range bike like this.

BB heights around 60mm or less are what you traditionally find in a CX frame.

If this is Bike Forums, you are most likely overthinking them.