I think this graph has been referenced a little too frequently here.Singular wrote: ↑Thu Jan 06, 2022 9:09 pmLike mentioned, it is one of the marginal drains;FlatlandClimber wrote: ↑Thu Jan 06, 2022 7:53 pmLike how many watts do you think the smaller chainrings make up? 3W at 300W? Hard to imagine it's more than that.
It's not like Gravel bike chainrings are that tiny compared to a climbing set up on an RB (46/30 or 48/31 vs 50/34 or in SRAM 43/30 vs 46/33).
For 1X the difference is probably even less. You have smaller Chainrings, but larger sprockets.
There are many reasons why a gravel bike is slower (geometry, tires, weight, usually no focus on aero), but I don't think chainring size is a noticeable factor really.
The crux of smaller/single chainrings is that you have to use smaller sprockets too for the same gearing.
In the middle section, the gears are seperated by a watt or so. The far ends of the gearing (48/10) is not a gearing you use frequently in gravel (maybe never?).
I don't think it makes a ton of sense to compare gravel gearing to 53/39, but rather to 50/34 (at least for me).
So what do you thing would be the difference in friction between 50/34 road or 48/31 gravel?
Also, in gravel you usually don't want the "same gear".
I don't know how people use their gravel bikes (Ronald Kuba uses his as a Winter road bike, and goes 20% hard pack, 80% Road... Fine).
But if you really go rougher gravel, steeper forest paths, mud etc, road gearing just doesn't cut it. You need small gears and don't need tiny gear jumps or a 4.8:1 top end gear.
So my thesis would be:
Gravel gearing is smaller because you go slower (higher friction tires, slower rolling surface, more technical riding, steeper roads, less traction in corners and on climbs), not the other way around.