You must have these if you remove your chain for any reason, you can not reuse the old power link. If you are using the Sarm Red or Force 12 speed AXS groupsets this is the powerlock to get. MAKE SURE you get the right powerlock there are others that look the same but will not work, The power lock is easy to use ,you just have to line it up right so it snaps in correctly and locks the arrow on the power lock has to point in the direction of the pedal stroke, moving forward. If you have not used them before might want to get 2 sets just incase of a mistake, i installed mine and was just a little off on lining it up and only half snapped in and i could not get the other side to snapp closed i had to remove it and you cant reuse it cuz one side was locked and not the other, dam it, any ways buy 2 and your covered.
the pros don't have to worry about stuff like this, it's up to their mechanics and their sponsors. my sram wi fli has always been impeccable and predictable. my mechanic adjusts the front and rear and off i go. but recently, i right after the adjustment, i was getting extraneous noise and missed shifts and poor tracking with the chain. the chain was new, so i decided to swap out the jockey wheels. bingo. smooth drive train once agin. there was so much lateral play in the old wheels due to wear and tear, it was sad. easy to overlook, but they can be a source of misery for someone who demands a smooth drivetrain and shifting.
Upgraded my red wifli Etap Rd with this updated version, primarily for the fluid damper as I use it for gravel. I've only used it for a handful of miles, and this initial impression is relative to the RD it replaced. A few observations. Unlike the photos and the previous gen rd, this item does not come with a battery, a big negative for the price. It's also heavier than the old one by about 25%. The led light is brighter which makes it easier to see. It paired up with my shifters with no issues. The cage is slightly smaller to compensate for the larger pulleys providing about the same chain wrap. I use it with a 36t large cog and seems to be able to shift the wide range slightly better than the original rd, though not as well as either with a 32t. The upper pulley is concentric with the cage pivot rather than being offset which means the pulley gap to the sprockets is now independent of the cage angle which is a plus for a wide range 2x system. The shifting actuation appears slightly faster and so far feels slightly more precise, but more similar than not. The fluid damper works to significantly reduce chain slap and seems to be effective. The lower pulley uses narrow wide teeth which should help keep the chain inline. Time will tell if the cost is worth the upgrade, it's expensive but the features seem beneficial. Will review again after some time.
I worked on a lot of bikes this summer, including ones I refurbished to donate to kids in need. I jokingly started to say that "the chain is never good" when asked about how the work was going. For fixing shifting problems, jumping sprockets under load, and just generally getting an unrideable bike to work o.k., a replacement chain was second only to tubes for getting bikes on the road. I still need to order a couple more, and this size chain is the most commonly needed one for the multi-speed bikes I saw this year.