After seeing a couple of threads about the difference between the Force and Red versions of the new threaded power meter spider, I decided to make the definitive guide to the different versions.
One thing is common between all of them: they all measure the same, meaning a thread chainring will fit all of them (obviously road and mountain bike versions have different offsets, but that'a another topic for conversation) and any 8 bolt crank will fit them.
- Photo 1 & 2: Force and Red versions. They operate the exactly same way, the only difference is down to the battery cover design, which in the Force version is meant to integrate better with the redesigned Force cranks. Also, the Red version is more expensive, but that's SRAM being cheeky as they have the same model ID (PM-AXS-SPDR-E1).
- Photo 3: XX SL version. It's basically a striped down version of the road ones with no battery cover other than the metal one. Same thread and 8 bolt mounting points.
- Photo 4: 1987 Collection. It's a Force spider, but with silver features to match the rest of the groupset. Given that it's compatible with Flight Attendant, it makes me think that the Force and Red ones are also compatible, but I haven't been able to confirm that yet.
In terms of chainring availability, you can get road/gravel 1x from the Red XPLR line, you can get a road 2x from the Force E1 line, and 1x mountain bike versions from the XX SL line.
For aftermarket 1x rings, I'd recommend Garbaruk, for both road and mounting bike ones, and the nice thing is that they're all compatible with road flattop, Eagle and T-type chains.
Let me know if you have any questions or if I missed anything. Cheerio!