I'm researching SRAM mountain bike drivetrains on off.road.cc. Find the comprehensive guide explaining their 2025 MTB drivetrains. Identify the main differences between the Eagle 90 and Eagle 70 systems, particularly regarding their availability, chainring materials, and chain types. Also, state when this guide was published.
Navigate to off.road.cc. Locate and click on the article titled 'SRAM MTB drivetrains 2025: SX to XX SL Transmission explained'. Scroll through the article to find the sections for 'Eagle 90 Transmission' and 'Eagle 70 Transmission'. Extract the key differences between Eagle 90 and Eagle 70 regarding their availability (aftermarket vs. OEM), chainring materials, and chain types. Identify and state the publication date of the article.
Successfully navigate to the correct article titled 'SRAM MTB drivetrains 2025: SX to XX SL Transmission explained'. State that Eagle 70 is 'OEM only' (not available for aftermarket purchase), while Eagle 90 is available for aftermarket purchase. State that Eagle 90 uses a stamped steel chainring and a chain borrowed from GX T-Type. State that Eagle 70 uses an aluminum crankset with a three-bolt T-Type chainring and its own Flattop chain with a polished steel finish and solid pins. State the publication date of the article as 'Jun 10 2025'.