New SRAM Red XPLR 13-speed & UDH
What is SRAM launching
Just months after the launch of the new SRAM Red 2x12 groupset, SRAM is launching its XPLR version of Red. But unlike in the past, this is not a similar groupset with no front derailleur, one less chainring and a bigger cassette/RD range. Instead of going 1x12, SRAM is going 1x13 (count them below if you must). While that is nice, whether or not it's really useful depends on the details such as cassette range. We'll discuss that here.
What is new, what is known?
The completely new parts on this Red XPLR groupset are the rear derailleur, the crank and the cassette.
REAR DERAILLEUR:
The rear derailleur is Transmission style, which is SRAM's name for derailleurs that attach directly to the frame without the need of a derailleur hanger. Some people are confused about Transmission vs. UDH, so we've put the basics here.
The Red Transmission rear derailleur contains all the advantages of Eagle Transmission when it comes to alignment and sturdiness (you may have seen some videos showing how strong Transmission is, it's impressive).
One important thing to note though, this Red XPLR rear derailleur only works with one cassette, it is NOT compatible with bigger Eagle cassettes. This is not only because Eagle is only 12-speed but also because the derailleur and cassette work together as a system and so the derailleur needs a 46T biggest cog. Which brings us to the:
CASSETTE:
The big news of course is that Red XPLR comes with a 13-speed cassette. This is the second drivetrain that comes with 13 cogs (after Campagnolo Ekar) but the first one that is electronic. There is only one cassette available and that is a 10-46T (for those interested in the details, the cogs are 10,11,12,13,15,17,19,21,24,28,32,38,46). Not sure if any other cassettes will become available. The rear derailleur is a brilliant design but part of that is its simplicity. So you won't find some of the normal adjustment options, making it hard to get it to work with anything other than a 46T biggest cog.
Luckily, 10-46T is a great range for many applications so I think this will find brought appeal (to be honest I prefer 10-44T or 10-42T for pure gravel/allroad, and then go to 10-50T or 10-52T mullet for the really rough rides, but 10-46T is stil la 9.5 out of 10 in my books).
CRANK:
SRAM has offered two chain lines for a while now in road/gravel. They have 45.0mm as the standard and 47.5mm for more clearance. Which crank is offered with which chainline is a bit of a mix (some would say a mess). 2x cranks are 45mm, except for the 43-30 combo which is 47.5mm. 1x cranks come in both for some group sets, but only in 47.5mm for others.
With Red, you see these specs streamlined more. All 2x cranksets are 45mm chainline, all 1x cranksets are 47.5mm. This makes sense, as 2x is used mostly for road and fast gravel, where tires are smaller and clearance is less of an issue. 1x is more dominant for tough gravel, where tire are bigger and the 2.5mm extra chainline (equating to 5mm extra tire clearance) is very welcome.
THE REST
The other parts you may already know from the new 2x12 Red groups, as they haven't changed. So the very nice new shift/brake levers and updated brake calipers are also part of Red XPLR.
And the Hammerhead Karoo is there, which is my favorite bike computer right now, even though it has an insanely annoying beep for the alerts. So brutal that the first thing I do when I turn on the Karoo is to turn off the sound. Yes, it is that embarrassing to ride around with that beep. I do not know how this made it into production but more improtantly, how it is not possible to adjust the volume or the tone (the previous Karoo had a perfect tone and volume, so the none-adjustability was not such an issue). And no, it's not just me. But other than that, fantastic and hopefully there will be a software update soon for those alerts.
Compatibility
Red XPLR Transmission will be compatible with all future OPEN frames. these future frames will also remain compatible with all other levels of 1x drivetrains (so Force, Rival, Apex for SRAM and also Shimano GRX and Campagnolo Ekar) and of course 2x drivetrains (except for 1x specific frames, we will continue to make some of those too and I must say, some really nice ones :-)
Current frames will of course remain compatible with all the 1x and 2x drivetrains as mentioned above, but not with new Red XPLR. So if Red XPLR is what you want, stay tuned as we have lots of stuff coming.
Ekar wasn't the first with 13 speed, I believe that was Rotor. https://www.bikeradar.com/reviews/components/groupsets/groupset-road/rotor-1x13-groupset-review
Do you happen to know which cog of the cassette is in line of the chainring with straight chain? I.e. where would the greatest "cross-chaining" occur? Evenly split between biggest and smallest cog (when the gap between 6th and 7th cog would be at chainline distance) or more optimized in favour to climbing gears (should it be 7th or 8th cog) or faster gear (if rather 5th or 6th cog). I tried asking Sram but while they sometimes are so kind to answer this time they haven't (yet). P.S. See it exactly the same: I'd either prefer a slightly tigther gap for "good" gravel and would always directly go to 10-51 or 52 for rougher stuff. Well, actually even different still: Everything which doesn't call for an mtb cassette is Road, Allroad, Champagne Gravel and thus #fastfar for me. And there I prefer 2x. So it's either 2x or MTB 1x. Doesn't mean 13spd XPLR is a bad idea or won't be a fan favorite. Who really had a good use case already for 12spd XPLR will have with 13spd also, and even a bit better (sans maybe even greater cross-chaining and even greater efficiency and durability losses).
Pourquoi ne pas produire une pièce qui remplace le hanger sur les cadres actuels pour rendre les cadres compatibles avec la nouvelle norme. Certains constructeurs et After market le propose déjà. Cela évite l'achat d'un nouveau cadre. C'est bon pour la planète et cela respecte les clients fidèles. (Je possède un min'd un upper et un Wide ! Et j'adorerais passer en 1*13 axs....
So true about the new Karoo. Responded to a survey from them and it was the first thing I mentioned for sure.
Yep, it's surprising it made it all the way to production without anybody noticing. Or all the people at Hammerhead ride in very loud forests!
I thought one of the functions of a derailleur hanger was to protect the frame from damage in the event of an impact to the derailleur. Doesn’t the absence of a hanger put the frame at greater risk?
Not needed in this case, with the Transmission RD really attaching to the rear axle. If you look on Youtube, you'll find people jumping on their Transmission RD without any problem.
Great summary. Are 12s AXS shifters compatible with 13s XPLR?
Yes, see the compatibility chart: https://www.sram.com/globalassets/document-hierarchy/compatibility-map/road/axs-components-compatibility-map.pdf All parts within the same category are basically interchangeable between each other, e.g. you can use any of the listed shifters with any of the listed derailleurs (caveats apply, see footnotes)
It seems to me (speculation) that the shifters just tell the derailleur which way to move. The logic is controlled by the derailleur. Theoretically it should be able to handle more than 13 with a redesigned cassette. Physical range from inner to outer would be the limitation.
according to rumours: after pairing, the levers know what to do