The way I justified is for a specific purpose build.
- Easy to clean
- Run Eagle Transmission
- Simplicity of operation with wide gear range
I have other bikes with 2x. So the real answer is to enjoy both.
5 Likes
11 posts were merged into an existing topic: Best Racing Gravel Bike 2023
Does anybody have data on aero savings and weight savings of 1x?
@oldandfast for a shimano 6700 crankset with a dura-ace 53-tooth chainring at 0 yaw, 6 watts at 40kph.
Because the change is asymmetrical +/- yaw is different, of course, but generally speaking yaw behaviour is as you would expect…better performance at higher yaw but only for crosswind on the drive side. For crosswind on the non-drive side it’s kinda like nothing happened.
My experience is, most of those gains are due to the front derailleur. So if you wanted a quick change you could just take the derailleur off, hide the wire, and capture most of the gain.
1 Like
Josh Poertner had some in the last AMA episode of the Marginal Gains podcast.
2 Likes
because of John Cobb, I rode TT with ear plugs for half a decade. 
Going from a 50/34x11-36 to a 38x11-42, I did not get much weight savings at all. The increased weight of the larger cassette and long-cage rear derailleur offset almost all of the weight saved from parts that were removed. The weight savings was pretty minimal (less than 100g)
2 Likes
I know this isn’t answering his direct question, but I had a similar experience going from Rival 1 mechanical to Force axs mullet set up. I think the different in weight between the two group sets was about 30g.
1 Like
In any event, it’s not too hard to just weigh the derailleur and (inner) chainring. Then you’ll know for sure.
If I switch to 1x I’m not changing the cassette at all. So the weight savings are material in that regard BUT completely not material because the course would be mostly flat.
1x is just so simple. I want more gear or less gear you shift. You dont have to worry about dropping the front to get into an easier gear.
4 Likes
Mates overshoes were full of holes after a little hike-a-bike and throwing the bikes around… turns out it was the exposed 2x chainring cutting them up. Good enough reason for me.
Im on the fence. My bike came 1x and when im on dirt it’s perfect. It would be nice to have 2x because then the bike would work nicely as an endurance bike when its muddy out. But offroad im so focused on not dying 80% of the time, and 1x is nice for that. 42t with 11-46 on Sram Apex 11 is fine for 99% of my use cases.
4 Likes
As long as we’re revisiting this, do we know how the frictional losses compare with AXS 12 speed (and in particular XPLR, probably the most common 1x setup)? And perhaps with hot melt wax? I believe the original test was done with mineral oil as a lubricant.
I think there’s some suggestion that SRAM flattop chains are a watt or two more draggy than Shimano chains, with Red actually slightly worse than Force. Does that drag compound at high articulation? What about Wide setups, where chain line is shifted outboard? It sure FEELS like there’s a lot of drag in the 40x44 gear on my XPLR Wide setup; chainline is very crooked plus quite high chain tension from the derailleur due to big-big combo. Since that’s the lowest climbing gear I’d be bummed to be losing 10+ watts to drivetrain friction while already dying on a long climb…
I imagine the trends from the original article will hold, I’m just wondering how many watts we’re actually talking about. 1-2 watts I don’t really care. 6-10 watts….is a lot.
1 Like
So I’m converting my road bike to 1x with the same gearing (except 10 speed), what issues do you have when riding on the road? Is it mostly the large gaps between gears or that 42t is not enough up front?
I’m going to switch my gravel bike to 2X. Like you say, the 1x is fine off road though I’m spun out on some downhills (44x11).
Now, I’m doing various gravel fondos in my area that are half gravel and half road. I don’t have quite enough of a climbing gear (44x40) and I don’t have enough big gear for downhills plus I already have large jumps on my cassette (11-40).
If I make the front chainring smaller I lose more big gear. If I make the rear cassette wider, I get more jumps in the cogs. 2x seems to be the right solution.
Maybe a 10 toothed cog would be a solution as there are aftermarket 10-42 cassettes but I’d need to convert my freehub to XD.
I really like my 2x on my gravel bike.
1x is perfect when you have a narrow speed range such as a mtb or TT bike.
If my gravel was pure off road 1x would be good but I use it as a winter bike as well so it spends a lot of time on road for me.
One of my gravel bikes has a 40 with an 11-32 and the main problem when using this on the road is using the 11-13 cogs so much. I don’t mind being spun out (unless actually riding hard with a group), but I’m in those smaller cogs way too much and the efficiency isn’t’ great, not to mention the wear on the bottom of the cassette.
Unpopular opinion or unspoken rule (?)
If you are running wide gravel tires go 1x. If you are running skinny’s then go 2x.
3 Likes
What is “wide” in your mind? Also is your logic basically the faster you need to go, go 2X?
That’s not unpopular… and it’s only unknown to those that don’t bother to check specs for FD tire clearance. It is definitely a factor among the others that are all worthy of review when someone is spec’ing a modern gravel bike.
Just a couple examples:
Max rear tire clearance for the standard front derailleur, depending on frame design, is 42mm (measured width) for 700c tires. Bikes with tires wider than this using a standard road width chainline can be built using the 1x drivetrain option, or the wide front derailleur and crankset. The Rival eTap AXS wide front derailleurs, made for use with the 43/30T crankset, will accommodate 700c tires up to 45mm wide or larger, depending on frame specifications.
SRAM eTap AXS Wide front derailleurs with 43/30 Wide chainrings will accommodate tires up to 700x45c and 27.5"x2.1" depending on tire, rim and frame variances.
3 Likes