I’m building up an SWorks Tarmac and am considering the SRAM ETAP AXS Groupset. Obviously I have read the reviews but wondered if anyone on here had been using it in anger and what you thought?
I’m not concerned about the Wireless shifting etc, I’m purely interested in the ratios and how you may have found it in real life scenarios.
Anyone raced on it?
Anyone found that whilst a 10 tooth cassette gives a bigger gear, the fact that the 11, 12 and 13 tooth cogs combined with a 48 up front just doesnt compare to the traditional 53 chainring and 11,12 and 13.
I’ve not had time to do the old sheldon brown gear inch calc yet, I’m more interested in real world experiences…
I have been using my 2019 S-Works Tarmac w/SRAM eTap AXS since I bought it in mid-March and have put on about 2200-2500 miles (with ~ 80-100ft/mi). I’ve used it in everything from endurance rides to spirited group rides (I ride with a race team and serious cyclists), to hilly road races. For comparison, my 2015 Roubaix Pro Race version has Di2.
I have to run off to pick up my daughter at the airport, but I’ll provide my experience thus far and happy to answer additional questions later today . . .
My feedback below attempts to respond to your specific question, but also a broader comparison for those interested:
High level summary: Based on the type of riding I do described above, Shimano’s Di2 and SRAM’s eTap AXS are both great systems. Each has its distinct advantages and disadvantages relative to the other. The best choice really depends on which tradeoffs are most important to you. (i.e. it’s not “you can’t go wrong with either decision”).
Gearing: Prior to purchasing, in addition to all of the mechanical advantage calculations typical in gear-charts, including those that allow you to compare 2 different systems, [using excel] I did the change in mechanical advantage calculations as you shift up and down. This, of course, leads one to easily see the SRAM 12 speed (over Shimano 11 speed) advantage, particularly using sequential shifting.
However, in the “real world” of spirited group rides and races, sequential shifting is too slow, and more specifically, shifting from the big ring to small ring or vices versa, regardless of whether it’s a Shimano or SRAM. As such, what really matters is the gear range, gear spacing and shifting speed WITHIN the rear cassette.
In this regard, I enjoy my Di2 but love my AXS. In the little ring, you can cross chain up to 11 cogs. But in the big ring, you can cross chain across all 12. What this means (has meant to me), is it allows transition from a hill to a flat to rolling downhill with much tighter transitions and therefore smoother and faster steps in power. Going OTF on one of our group rides, and similarly, catching a break on a hilly descent in a spring RR was fun!
The other SRAM gearing advantage I have enjoyed is being able to stay seated longer on hill climbs (you can see from the kind of riding I do why this is important). I chose the 46/33 x 10/33 combination and it provides the same upper end of my Di2 (50/34 x 11/32), [actually its slightly more, but not noticeable] but gives that one lower gear (1.0 vs. 1.06 ratio) that is really noticeable. Tonight for example, is our club’s well known and well attended SF Bay Area ride, known as “Egan”. It’s a real suffer fest of typically 8-12 (tonight is 19) hills of 0.25 to 0.75 miles (short) but 10-20+% in grade. I’m improving anaerobically and PRing consistently due to being able to sit longer, that I know will translate into punchy hills in RRs. It already allowed me to crush a 4mi/10% climb by 2 1/2 mins during a hard paced century ride I PR’d last weekend (100mi/11kft).
Note: Regarding a standard 53/39 x 11/32 vs SRAM’s 48/35 x 10/33 gearing: sure, they have the same upper end. But if you have a big engine and race crits or circuits, why wouldn’t you select the 50/37 ring combo? It would give an upper end advantage of 5.0 vs 4.82).
Shifting speed: I have not noticed any difference due to the wireless on shifting amongst cogs in the rear cassette using the Di2 vs AXS. HOWEVER, I have noticed a SIGNIFICANT difference in shifting in the rings (advantage: Di2). There is a great YouTube video (very sophisticated testing using audio pulse wave analysis) of the prior generation eTap vs Di2. Lots of details in the testing results, but in summary, Di2 is faster, on average by 100-150ms. In addition to being faster, Di2 shifting speed is less variable. If you are interested, let me know and I’ll provide the URL.
My experience: While SRAM claims to have improved their wireless protocol, and while I don’t own the prior generation to compare, ring shifting speed of my SRAM is both consistently slower than my Di2 AND highly variable. This is especially true if there is substantial tension on the chain, such as transitioning from the flats to a hill. I have learned to deal with this issue by anticipation of the gradient change in the road and therefore shifting earlier, but it’s definitely not ideal. In my first RR with the bike (40+mi; 4kft), I literally stalled after a fast 37mph 1.5mi 2% downhill transitioning to a 0.5mi 8% uphill. It cost me several seconds, but fortunately, not a loss in race position (5th of 11).
SRAM shifting is more intuitive
SRAM derailleur batteries are easier to charge
Let me know if I didn’t answer your question(s) and/or if you have additional questions.
You make a good point here. But I think something nobody talks about wrt very small cogs being introduced (first in the 3T 1x setups/ Eagle and now AXS) is that there is a not insignificant amount of drag being introduced into the drivetrain w/ tiny cogs.
TT bikes roll w/ big front chainrings and derailleur pulleys for a reason at the WT level.
But for sure the AXS gear range is very impressive and nice to have esp someplace like SF.
lol, spend anytime on the Slowtwitch forums and mention the new AXS system and that’s all they seem to talk about.
I think people often overestimate how long they’d actually be spending a large amount of time in the 10T cog. I’d much rather take a small efficiency hit over the larger range especially if I want a do it all bike (unlike sponsored WT pro’s)
I read about that point some months ago in the post @mcneese.chad referenced. However, SRAM 12 speed chains are thinner than 11 speed Shimano chains. So if you did the math on the surface area of the chain in contact with the 10 tooth cog on SRAM at any point in time vs 11 tooth cog on the Shimano, “I bet” that they are similar. FWIW: I didn’t noticed any additional drag and I was looking for it when I first bought the Tarmac due to the comment in the other post.
In my observation there is a very vocal minority who seems to care a great deal about that. The singular focus on drive train losses, though, does not take into account lots of other practical advantages such as having more closely spaced gears on the top end compared to Shimano’s 11-speed drive trains with equivalent gear range. Or how much time you actually spend in which gear. Or total reliability.
I agree with every point that you made in the post . . . except this one. And my call out of this (relative to Shimano) is strictly focused on the wireles protocol/delay issues I identified. I was in the telecomm industry for 25 years and have a pretty deep knowledge of both wired and wireless protocols and hardware systems over all sorts of mediums, environments, etc. It’s too complicated to explain here, but the gist is that I get the sense that SRAM AXS is gen 2.0, mode and still has a ways to go to reach maturity - that SRAM has improvements both on the chip hardware side that implement the protocol and to the protocol itself. All other parts of the AXS system, including the new 12 speed chain and cassette feel quite robust (e.g. last night’s suffer fest was 19 hills of VO2M efforts; 120ft/mi and the system was rock solid).
Hi have an S-Works Venge ETAP AXS. First up, awesome write up bobmac. You ain’t gonna get that detail from me! I have 48/35 10/33. I live in a hilly area and have found these ratios perfect. The gear changes are very slick. As mentioned above, I find I don’t have to drop into the small ring anywhere nearly as much as my other bikes. Drivechain, big tick! Front breaks big cross. FIVE weeks of front break issues with eventually all parts including the lever being changed under warranty. Seriously unimpressed with the naf customer service from SRAM!
I presume you mean 10/33 rear cassette vs 10/22 (the rear cassettes they offer are 10x 26, 28, and 33) . . .
My test ride (on varying terrain) was actually on the 48/35 x 10/33 and I almost bought it right then and there that it was so much fun. The upper end (48/10) 4.8 has a 6% mechanical advantage over the 50/11 combo. One of the test sections of road I tried was flat/rolling section. It was a blast! On my Di2, I run out of gearing consistently if the pace is high enough. I did so here as well on my test ride (I drilled it), but it was at a later section of the road that I ran out of gearing than I would have on my Di2. And I could easily envision sections of our normal spirited group rides and in races where the higher gearing would be really nice to have. [It was crazy thinking, but I even though about the 50/37 combo, but 37/32 combo would be much too hard for me to climb in].
At the low end of gearing for the 48/35 combo, the 35/33 (1.06) is the same mechanical advantage as your current 34/32 (1.06). So this is long winded way of saying/asking: If you were to get a gearing improvement, would you prefer it at the upper end vs lower end? There are a few things to consider (or at least that I considered):
What kind of riding do you currently do/enjoy?
Do you find yourself running out of gearing on the hills? How frequently? When/where? Is it a big deal for you or an ocassional “annoyance”?
What kind of riding do you envision doing over the next few years?
[in my case] If you are on the older side, and you like climbing hills, the lower gearing will provide longevity to the bike (obviously the rings/crank can be replaced, but it’s expensive).