I agree…but when 1x gravel trains were in development the gravel scene was ignorant of this data. For sure, I did not understand the inefficiency of a 1x drive train. And definitely I never had a 1x setup that included a 10 cog. Or any setup that included a 10 cog…right from the get go I understood that the extreme articulation required to wrap a chain around a 10 cog was crazy inefficient.
Also, the major impetus to switch my setup to 1x was jamming my chain on the 2x setup while riding the Dirty Kanza course just for fun one year. That ended my day and I decided that would have sucked during the actual race…so I eliminated that risk by going 1x.
So I think there are a few things that need to be added to the discussion…
for the “meat of the curve” (i.e. where the majority of us are gonna find ourselves during a gravel race), there is not a lot of meaningful difference in wattage (~2w in the area just north of a 2:1 ratio).
They have not isolated the differences in chains. SRAM chains are notably less efficient than Shimano chains…on the magnitude of 2-3W. So it may not be jsut a 1x / 2x discussion.
Or you can just get the best of both worlds like me and run a 1x Shimano system.
In my experience no. Any 2x drivetrain without narrow-wide teeth will drop chains. In my gravel group rides, 2 guys have GRX 2x drivetrains and both drop chains. I have literally never once in thousands of gravel miles ever dropped a chain with a 1x narrow-wide chainring.
I drop chains with some regularity when I ride my 2x setup gravel bike.
Also, a well-setup gravel bike will account for cross-chaining losses by matching the chainring size to the terrain so that most of the day is spend with no-loss alignment.
In the end, however, I favor a 2x setup for one reason alone…I ride a lot of steeeeeeeep gravel terrain and I simply need the range of a 2x.
My current setup is 46/30 front and 11-42 rear. this gives ridiculous range (589%). I can climb all day and still keep up with the paceline at the end of the ride returning to our cars. I just have to be really careful when I shift especially from the big chainring to the small.
I would say that both can drop chains but the frequency is much greater with 2x. I ride both and personally can’t remember ever dropping a chain on my 1x including during 5 years of CX racing, but have dropped chains on 2x many times.
I would agree that is is possible to drop a chain on a 1x and likely to drop a chain on a 2x.
I don’t think that a roadlink or goatlink will work. They both increase the maximum cassette size but do not increase the amount of total chain links a derailleur will pull. I used a Garbaruk cage extender on a GRX 11sp derailleur.