The next level.
We have some bad news. You may want to be sure you're seated for this. SRAM is effectively retiring its XO brake models. This saddens us because they've been like a good friend at the bar for so long, stopping us when maybe we've gone a bit further than we should; however, the bright side is that the X01 brake is being replaced with the new Level TLM Disc Brake. The Level TLM recreates the upgrades field tested on the enduro-specific Guide RSC brakes in a low-weight platform designed for XC use.
Compared to the Guide RSC, the Level TLM shaves a claimed 25g by cutting the pistons from four to two and replacing the tool-free reach adjust with a design that saves weight but does require tool intervention. The discerning weight watcher will notice that, despite these savings over its Guide equivalent, the Level TLM gains a claimed 46g in weight over the X01 brake it's essentially replacing; however, we contend that it's worth it for the Level's functional improvements.
Instead of the two-part body used for the X01 brake and almost every other member of the newly minted Level family, the Level TLM houses its pair of 21mm pistons in a forged, single piece caliper for net gains in stiffness and braking consistency. The TLM model does make some material concessions to the top-end Level Ultimate. Instead of titanium hardware, the TLM features redoubtable steel; instead of the carbon lever used on the Ultimate and Xo1 models, the TLM rocks alloy. The only other difference between the TLM and the Ultimate is that the former substitutes a bushing instead of bearings to govern the lever action.
The Level design features a host of improvements over the occasionally disappointing Avid Elixir. Among these is the notoriously finicky bleeding of the Elixir, and the Bleeding Edge redesign we first saw in the Guide brake line carries over to the Level. Bleeding Edge involves a complete re-imagination of the port and fluid path. It requires a specific adapter, but that adapter ensures a tight seal to keep air out and fluid in. The new bladder design also contributes with a shape that reduces air contamination by expunging air from the lever and reserving the lines for fluid only.
The Level TLM also features the same heat-dissipating technology as the Guide RSC — most notably the stainless steel Heat Shields and the improved heat management of SRAM's DOT 5.1 hydraulic fluid. SRAM claims that the latest generation of DOT resists boiling for three times longer than its predecessor, DOT 4, and the Heat Shield inserts serve as a firewall to separate the brake pads from the calipers so that less heat overall makes it into the fluid system. While it doesn't play as important a role, the single-piece caliper body does also contributes to heat management.
The Level's bleeding, bladder shape, and heat management all contribute to its ability to mimic the Guide brake's consistent bite and lever feel, and the sealed bearings and SRAM's new timing port closure design ensure that the levers themselves maintain the smooth, one-finger operation we've come to expect from SRAM's new generation of stopping systems. The levers are MatchMaker and MMX compatible, and the PiggyBack Reservoirs let you run the brakes moto if that's your jam.