If you want a 1x and have the flexibility to go road/CX/Gravel/MTB check:
If you’re buying AXS you’ve got the money to just buy a second set I guess
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The mechanical engineer in me has to comment (OCD part of engineering). Most of the losses in a chain/cog/pulley system are in the tension side of the system, since friction forces are roughly proportional to the normal load on the surfaces. So yes, in a bike system losses are in the 1-2% range, and the largest factor is drivetrain cleanliness; the others are chainline (this one is peculiar to derailleur systems) and pulley (cogwheel) size. But most of these losses are on the cassette “exit” and chainring “entry”, as these are the high-tension points in the system. Smaller cogs have multiple effects: they increase chain tension (inversely proportional to cogwheel radius/ tooth count), and increase cog wear (higher load, less teeth).
This said, these are fascinating issues from an engineering standpoint, but their relevance to a bike’s performance is negligible. The social impact from showing up at a group ride with a compact crankset are way higher than the performance impact.
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Bruh, happening to the industry? Since I started working in the industry 21 years ago I’ve heard that line so many times and not always by retro-grouches.
1.125" headsets on road bikes, tapered steerer tubes on road bikes, compact geometry, Metronic, R-Sys, 7800/7810, RED, BB30/PF30, Scandium, CF soled shoes (circa 1998 - 1999), SRM, Lew wheels, ceramic bearings, PTFE, Ceramic Speed, Chain-L, CF, Cannondale moving production to Asia, Serotta’s $24,000 faux woodgrain bike, every product offered by Edge/Enve, Kogel bearings, Assos bibs, Rapha’s membership, the cost of a cup of espresso, Specialized Purist water bottles, hydration packs (I remember that discussion vividly).
We move forward. We cram more shiz into smaller things. We make things lighter. We make things more precise. Early adopters pay highly for the first gen. Folks make fun of the early adopters. Folks buy the trickle down stuff and then say they could never go back.
Over and over and over and over and over again. I catch myself doing it too. Then I remind myself that I could pick up some sweet 9 speed Ultegra or a Dura Ace 25h anniversary gruppo with a watch and suitcase for 1/4 of what I paid for my CF hoops.
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I don’t know Rotor well, but this seems like a great solution for gravel. Also, as you suggest, perhaps it is a great solution for a versatile single bike (i.e. n=1). But, for those of us looking for serious road racing bikes outfitted with Shimano Durace or SRAM AXS, the Rotor solution doesn’t appear to be in the same league.
Out of interest, what makes you say that?
Well, that’s fair enough.
I don’t actually mind if things are super expensive, I mean I owned a pair of Lightweigh Gen 2 wheels back in the day but, you know, they were just better than other wheels but cost a lot for the privilege, even second hand. They didn’t lock you into some manufacturer specific ‘standard’ though so you could swap them out for £90 wheels whenever you wanted.
Mike
The lock-in has been an issue forever - I have a 40+ year old steel fram that was built for “French” BB “standard”, I can tell you a few things about lock-in… This industry is, in general, surprisingly good at maintaining some sort of backwards compatibility. I keep my bikes forever, and I can always find parts to do things that should be impossible to do. There are dead ends in technology (remember freewheels in cranksets, allowing shifting while coasting?), and the bleeding edge is just that - bleeding, but in general it’s not bad.
Managed to hit reply too early and didn’t finish what I had to say, but now I can’t be arsed…
Good list though.
One of the strangest ones was when Wolf Tooth, who are totally into direct mount chainrings, decided that they needed a better option and came up with a system where you could bolt a chainring to a spider so that you could change rings without having to remove the cranks. CAMO 
Mike
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I’d suggest taking a look at their gear ratios in their FAQ:
https://rotorbike.com/faq-1x13-groupset-road/
On their 12 speed, they achieve no better than Shimano’s Durace 11 speed in single cog step ups (~5% mechanical advantage per gear change) plus have a weight penalty of an
additional cog. Even on their 13 speed, their 5 single cog step up is doesn’t match SRAM’s 12 speed 6 single step increment plus the additional weight penalty.
I haven’t done the math, but a 1x with any of the cassette combinations they offer won’t achieve the gear range (e.g. 4.80 to 1.00 mechanical advantage range of the AXS) with tight step ups of either the Shimano nor SRAM.
None of the above is relevant to recreational riders, but they are a BIG deal to road racers!
Conversely, as an example, I rode a combo of dirt, gravel, and road when visiting my son in NH & VT. The terrain is flat and hilly in areas, but doesn’t match the extended climbs of the CA and Sierras. I rode a Specialized Diverge with a 2x front and Shimano 105 in the rear. I think a 1x with the Rotor 10-39 or 10-46 would have even better.
Same league… In don’t know. Their UNO groupset gets a lot of praise. They are just less know and a lot smaller then Shimano/SRAM/Campagnolo.
I think the big difference is, if what Rotor claims is true - that they analyzed the gear ratios of the riders to find the most commonly used ratios and then created the cassette according to that, then, you have a good setup. Personally, I’m very interested in running a 44-10/39. More than enough for training and racing in my area. I’ve been running a 1x for road and 50-11/32 is more than enough for crits and some road courses, but, I’ve been training on 50-14/42 and it’s a good setup, but not enough for the rare long sprint finish. Having an extra two cogs and be able to go down to 39 would be perfect.
Because I’m into spreadsheets…
I graphed the linear gear development of AXS, Shimano and Rotor for High, Mid and Low gear combinations assuming a single change between large and small chainrings at the point that gives the largest number of non-overlapping gears. Specifically:
High
- AXS 50/37 with an 10-26 cassette
- Shimano 53/39 with an 11-28 cassette
- Rotor 50 with a 10-39 cassette
- As you can see, with this combination AXS gets 17 unique gears with a very good progression.
- Shimano isn’t so smooth and only gets 15 gears.
- Rotor is smooth but with only 13 gears, the jumps are bigger. The overall range is larger than the other two with this particular cassette.
Mid
- AXS 48/35 with an 10-28 cassette
- Shimano 53/39 with an 11-28 cassette
- Rotor 50 with a 10-39 cassette
- Once again, AXS is very smooth with 17 unique gears.
- Shimano only manages 15 in this configuration.
- No change for rotor. (50t chainring chosen as it gives the same climbing gear and a slightly higher top gear.
Low
- AXS 46/33 with an 10-23 cassette
- Shimano 53/39 with an 11-28 cassette
- Rotor 40 with a 10-39 cassette
- AXS only manages 16 gears in this combination as the wider gaps in both the chainrings (as a percentage) and the cassette give wider spacing at the changeover point. It’s still pretty smooth except in that 6 to 7 and the 10 to 11 shifts, which is at the 15-17 step in the cassette.
- Shimano on has only one less gear in this setup and the smoothness isn’t bad.
- Rotor is struggling for range (40 chosen to match climbing gear) but is probably the smoothest of the three.
Obviously other combinations are possible for all three groupsets but it does seam that Sram have put a lot of thought into the gear combinations.
I’ll put the tables on here when I get more time so that it’s clearer what I did.
Mike
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@BMAC615 the 2019 Canyon Endurance comes with the AXS 48/35 crank and 10-33 cassette. How does that compare to a 50/34 11-28 cassette?
Thanks
Does someone already have found (or even tested for himself) real world performance info on the battery life of the etap AXS group?
I’m concerned that with the new dampened rear derailleur and the new, stronger motors and maybe also due to changes in the protocol and whatnot the battery life of the unchanged batteries might be seriously hampered.
It’s also peculiar to not see as detailed as information on SRAMs Zendesk FAQs regarding battery life of the new AXS as you can find on the old etap/etap HRD.
The new etap AXS certainly has a few nice points but it also comes with a few (severe) drawbacks regarding backwards compatibility to the former etap and also cross brand compatibility (chains, cranks, sprockets etc.) (Basically it’s a mess and I wrote at length about this and it’s implications here (Himmelhoch jauchzend und zu Tode betrübt – Gedanken zur neuen SRAM Red etap AXS – Torsten Frank . : : . tfrank.de – Das Blog in German)
The only thing I really like in the new AXS group is the tiny bit of added tire clearance of the front derailleur. The thing what concern’s me most right now as an endurance biker (24 hour all the way up to Transcontinental) are subtle hints that the battery life might seriously be shortened compared to the old etap.
It seems like on the new AXS the battery will last only in the range of 20+ hours and maybe 500 kms instead of 60+ hours and 1000+ kms (I typically have to charge mine only after around 1300 to 1500 km).
How’s your experience? Have some of you already had the chance to empty the battery and going through at least one or two use/recharge cycles to comment on the real life battery endurance of the AXS? Do you know others who have also have AXS already and might contribute?
Cheers
Torsten
Anyone know if it will be backwards compatible with a 1x11 system? EG can I slap it on my non-boost rear wheel and configure it to only account for 11 gears instead of the default 12?
Are you talking about the hubs? You will need an XDR driver, and for many hubs there are adapters.