SRAM has amalgamated its Eagle SX, NX, GX, X01, XX1 mechanical and Eagle X1 AXS, GX AXS, X01 AXS, and XX1 AXS (electronic) drivetrains into three new groupsets: mechanical Eagle S100 and Eagle S200, and electronic Eagle S500 AXS. This means fewer SKU (stock keeping unit) codes to build and stock for the industry, and less choice (and possible confusion) for consumers. The new Eagle S-Series derailleurs are only available in traditional-style threaded replaceable derailleur hanger mountings, so if you want a UDH-specific groupset, you need something from SRAM's Transmission range. However, SRAM has released a very smart product called the UDH Half Mount for the S-Series, designed to prevent damage for a bargain price. It reminds me of a different component from years passed. What do you get? SRAM's Eagle S500 AXS derailleur is gravel-, MTB- and road-compatible, depending on which AXS shifter you pair it with. SRAM SRAMs S-Series is for riders who want a SRAM drivetrain to run on a traditional derailleur hanger, not UDH. That's good news if you have an older bike and for manufacturers looking for OE drivetrains for bikes without a UDH option. SRAM is quick to explain this groupset is for gravel or road riders, as well as MTBers, extolling the idea of pairing the S500 derailleur with road eTap shifters and a 1x road crankset on the S-Series landing page. UDH Half Mount SRAM's UDH Half Mount derailleur plate costs only 10 and reinforces the S-Series derailleur. SRAM SRAM says the UDH Half Mount provides extra robustness in the case of side impacts, knocks and slams, and is created specifically to integrate with the Eagle S100 derailleur. It reminds me strongly of Specializeds HGR derailleur hanger guard from over a decade ago, in the way it bolts onto the concentric axle-mount and into the end of the derailleur to reinforce the body against knocks. Specialized's HGR looks similar to SRAM's UDH Half Mount, but had a less sophisticated interface with the derailleur. Specialized Its not expensive either, currently listed on sale by retailers for prices as low as 10 / $10 / 10. S100 SRAM's S100 Eagle groupset is your budget way into 12-speed SRAM groupsets and is shown here with its Half Mount UDH plate. SRAM Eagle S100 is the cheapest of the new SRAM S-Series groupsets, with a 12-speed 50-10t cassette offering a 455% gear range. The derailleur costs only 75 and uses SRAM's drag spring cage damper (instead of a more complicated clutch). Its compatible with up to a 50t inner cassette cog and SRAM's Half Mount UDH for MTBers looking for maximum robustness. The cranks are 75 including the chainring, the PG-1210 Eagle cassette with Shimano HG freehub compatibility is 95, and the S100 chain costs 35. The band-clamp shifter is also 35. SRAM is also catering for eMTBers and those jumping on the 'short cranks are good' bandwagon, offering the S100 crank from only 155mm in length up to 175mm. However, these are bolt-on rather than thru-axle, utilising SRAM's pre-existing PowerSpline bottom bracket technology. S200 S200 Eagle groupset offers 520% gear range thanks to large 52-10t cassette compatibility. SRAM The S200 offers a greater 520% gear range thanks to a larger 52-10t cassette. The shifter is Matchmaker-compatible, instead of using a band clamp, and costs 45. The S200 derailleur is described as a workhorse and uses SRAM's Type 3 clutch: it costs 145. The S200 crank (without chainring) is 90, the recommended XG-1275 cassette is 240 and the S200 chain is 45. S500 SRAM's S500 Eagle AXS groupset is the gateway to electronic shifting and is compatible with existing road and MTB AXS shifters. SRAM S500 is your cheapest way to access SRAM AXS technology, with the electronic derailleur costing 425. It uses the Overload Clutch found on SRAM's more expensive AXS derailleurs, which disengages the motor-gearbox in the derailleur during an impact before returning to its original position. No specific S500 shifter is listed on SRAM's website, but it will be compatible with both its AXS road and MTB shifters. The S500 chain costs 110, is available in Gold or Rainbow and is ebike-compatible. The SRAM-recommended XG-1299 cassette is available in Gold or Rainbow for 595. The S500 carbon crank uses a DUB BB, Boost spacing and costs 400 with a three-bolt aluminium X-SYNC 2 chainring. It is available in 165mm, 170mm and 175mm lengths.