SRAM Axs eTap user question

[rx7mark]

Planning a Silvio build for travel, and was hoping to use the Force Etap wireless system, but the RD range is a little light for what I want to use for gearing. I would like to use the 12 speed 10-33t cassette with a 46/30 chain ring set for a total range of 39t. The Force/Red eTap RD list 36t for the medium cage RD. But if I understand the programing possible with this system you can program it to shift to the little front ring prior to getting to the big rear gear. If the worst case would be 2nd gear 28t, prior to shifting to the 30t front chain ring, then the range I would have to worry about is only 34t, and the medium RD would work.

If this won't work, then I would need to get an Eagle RD which has a 40t range long cage, but this would cost a lot more to buy everything separately, and the Eagle RD is already more expensive, so a big price difference!

Can anyone confirm that you can program the system to never allow a big/big gearing combo? Any issues using this system on a Cruzbike?

Thanks in advance
Mark

 

[RojoRacing]

From a mechanical standpoint you're playing with fire doing what you want to do because if it ever glitches for any number of reasons like say one of the batteries dies, you'll risk destroying a derailer.

a 30ring and 33cog is already shorter than what most of us sport which is 34ring and 36cog, yes I'm aware some have gone even shorter. I get what you want but a question if you really need it.

Have you tried giving SRAM tech support line a call?

 

[rx7mark]

From a mechanical standpoint you're playing with fire doing what you want to do because if it ever glitches for any number of reasons like say one of the batteries dies, you'll risk destroying a derailer.

a 30ring and 33cog is already shorter than what most of us sport which is 34ring and 36cog, yes I'm aware some have gone even shorter. I get what you want but a question if you really need it.

Have you tried giving SRAM tech support line a call?

I will try that next, if I don't get an answer on line. My understanding is that it won't shift at all with a dead battery. But the FD battery lasts longer than the RD battery and they are interchangable. Or you can carry a spare battery.

I need the gearing on some of our Seattle area hills, or I have to walk. I hate to walk! And to make things worse I live at the top of a 800 ft hill, so every ride involves a climb on the way home.

Mark

 

[Beano]

Buy and fit a wolf link, running a 11-40 cassette with Red ETAP.
Also run a 40-46 gear using the Wolflink with a mid cag rear mech although I would not run high high as a general rule

 

[rx7mark]

Buy and fit a wolf link, running a 11-40 cassette with Red ETAP.
Also run a 40-46 gear using the Wolflink with a mid cag rear mech although I would not run high high as a general rule
View attachment 9465 View attachment 9466

Thanks Beano, that should work, I will contact Wolf to confirm.

What is your gearing combo, that you are running with the link?

Mark

 

[rx7mark]

I just checked on the Wolf site, and the link increases the largest cassette size you can use, but does not increase the total capacity of the RD. Still might need this, but won't solve my basic issue.

Mark

 

[ratz]

We tested that for RAAM. If you have the Red Short Cage you can't run 34x11 or 36x11; you will need the mid cage. Best to Chain it up with a chain that is long and sags so if you do shift into something like 50x40 that you don't jam and snap the cage.

 

[Beano]

Thanks Beano, that should work, I will contact Wolf to confirm.

What is your gearing combo, that you are running with the link?

Mark

50/34 * 11-40

 

[rx7mark]

OK, I talked to SRAM tech department today, and it turns out they just introduced a larger rear 12 spd cassette for Force eTap (10-36t) and a matching Force eTap medium cage rear derailleur, targeting the gravel crowd. The RD has a max 36t cassette, but also a larger 39t total capacity. So this looks like it solves my dilemma, even though what I have planned (10-33t w/ 46/30) is not what they intended, they told me it will work. I have to wait until its available, and much harder for me, until I can afford it!

Or the new Sensah Carbon Pro 12 spd group should also work with this gearing combo and its WAY cheaper. but of course not wireless. At least I think it will work, it's harder to get the specs for RD capacities for Sansah products. Anyone know for sure what the range of the 12spd road derailleur is? All I can find is the max cassette size, they don't mention the total capacity on the sites I can find in English.

Mark

 

[rx7mark]

Just an update. Talked to Rotor about cranks and chainrings for Etap. They only make one at the moment a 48/35t that fits the Adhula cranks, which won't achieve the gearing range I was hoping for. They did confirm that the 12 spd chain has the same link spacing as the 11spd, and is only a tiny little bit narrower, but should fit on the 11spd chainrings. They are not sure how well it will shift however. But since they haven't validated that it will work, using a 12spd chain on the 11spd 46/30t chain rings would void the warranty on the rings. They also said that from testing on the Etap the FD will only work correctly with a 13t jump, this is also what SRAM told me.

Rotor might be working on expanding the future offerings of Etap 12spd chainrings, but could not share the timeline. Since my build will not happen until this winter, I will wait and see. I could make anything from a 42/29t to a 46/33t work with one of SRAMs' existing cassettes.

As far as I know Rotor is the only company that could potential give me a combination that would give me a 155mm crank arm length and 12spd Etap compatible elliptical chainrings that can be properly adjusted for a recumbent. If they don't come thru with the Etap specific combo, then my backup would be to get the crank and 46/30t chainrings and try it with the Sensah Empire pro group to see if it will work/shift and see how well I like the groupset. Not too expensive of a trial, and who knows might be good enough.

Mark