Posh foot underwear (funderwear?). Do you get what you pay for?
It’s a compromise but it could save you a grand, here’s what we thought of the 1×10 extender cog
This SLX double chainset is a perfect example of a no-nonsense chainset that runs on a reliable, but simple, bottom bracket and it does the job with little fuss.
Light, powerful brakes that have great lever feel and just work consistently, no matter how long the descent.