Fifteen years ago this month, SRAM acquired Avid LLC, then known for making what is arguably the best cable-actuated disc brake in the industry, the BB7. Around the time of the acquisition, Avid introduced the Juicy, which became arguably the best hydraulic brake in the industry. Among its other innovations, the Juicy was the first to focus closely on the ergonomics related to lever blade pivot point. We take it for granted today, but positioning the pivot as close to the bar as possible meant the lever blade's path aligned better with that of your braking finger. It's just part of the reason why Juicys felt better and worked better than anything else out there.
Then, Avid introduced the Elixir, whose breakout technology was called TaperBore. The inside diameter of its master cylinder tapered down midway towards the tip. That meant more fluid was being pushed early in the stroke, allowing the pads to rest further from the rotor. And it meant less fluid was being pushed later in the stroke, allowing a greater mechanical advantage once the pads hit the rotor.
It also meant that a perfect bleed was absolutely necessary to keep Elixirs working. Any air in an Elixir brake was especially prone to getting stuck in places it didn't belong. On the bright side, if you were the original owner of one of those early Elixir brakes, you might have witnessed firsthand how serious SRAM is about solving problems. At the shop I managed at the time, we would sometimes have two or three customers a week getting factory-bled replacement brakes rush delivered, often in upgraded models.
SRAM's attentive warranty procedure stopped the bleeding (swish!) while they developed the Guide brake. Sans taper-bore, Guide lever internals are remarkably similar to those of the original Juicy levers. The system volume increased over Elixir for a greater margin of error. The bleeding process improved, and SRAM introduced ‘SwingLink,’ which is essentially a mechanical method of achieving Taperbore's desired results.
Oh, and that generation, SRAM dropped the name "Avid" from its entire hydraulic brake lineup. There may have been several reasons, but that helped distance the Guides from the troubles of the Elixirs. And then …
About three years ago, new troubles surfaced among Guide owners. Usually around two years after their born-on date, nearly all Guide lever pistons would suddenly get stuck in the master cylinder, rendering the brake useless until it got a rebuild with some fresh rubber. The issue got fixed on the production end long ago, but on brakes manufactured before it came to light, the material in the Guide lever seals would swell inside its DOT fluid bath. It wasn't the kind of problem that hundreds of thousands of use cycles could have exposed in a testing lab. It bears no resemblance to the issue Elixir brakes faced. It was just a case of cosmically bad luck.
The reason I just spent a full review's worth of words taking you through the history of SRAM's brake woes is because I just spent a full week on the brake will soon come to replace the Guide: the G2.
G2 Ultimate and G2 RSC are positioned equally to Guide in SRAM's lineup, right between the XC-oriented Level and the DH-focused Code. The RS, R, RE and T levels will stay in the Guide family, and are remaining unchanged for now. SRAM will offer replacement parts for all Guide models for several years to come, and G2 still uses the same pads, the same mounting hardware, hose fittings and ‘Bleeding Edge’ bleed system. In fact, a lot of things are the same between the Guides and G2s. The kinematics in SwingLink remains unchanged, as did the fundamentals inside the lever. The caliper pistons are the same size as Guide's, and the system uses the same volume of fluid. Most of the changes that did happen are subtle.
The ‘pad pocket,’ which is the slot you would pull the pads out from, is a little narrower than it was on the Guide, which makes for a stiffer caliper body. Also in the name of stiffness, the area around the bolts that connect the two caliper halves has been beefed up. SRAM claims this nets you a 7-percent increase in power, but more importantly, it gives the G2 a stiffer feel than the Guides. There's also been a subtle change in the structure around the piston seal to make pad retraction smoother and more consistent. A new hybrid pad material SRAM is calling ‘Power’ joins the existing metallic and organic options.
The hose material even got an update, helping keep it from holding a kinked-up shape after being wrapped up in a box for most of its life, hopefully leading to cleaner lines in your cockpit. And while we're at the cockpit, there aren't many significant changes at the lever. You'll notice the G2 RSC lever pivots around a bushing while the Guide RSC used bearings. The G2 Ultimate still uses bearings and still gets a carbon lever blade. The RSC lever pivot got updated hardware to make it as smooth and laterally stiff as possible, but the idea behind ditching the bearings was to bring the cost down. Combined with some refinements in manufacturing, that brought the $180 G2 RSC down $25 from its predecessor, and the $280 Ultimate down about $10. That does mean if you really just want a bearing in the lever pivot but don't care about the carbon blade or ti hardware, you'll be spending $75 more than you would have in the Guide era.
Beyond that, there were some aesthetic changes made to both the caliper and lever, but overall the G2 represents a subtle but definitely not insignificant evolution in SRAM's trail brake offering. And that's just about how I'd describe how it behaves on the trail.
That increase in stiffness is the first thing I noticed. It’s why the G2 has inched, ever so slightly, toward the Code family. I only rode the RSC version, and even without the benefit of a ball-bearing lever pivot, I still sensed the soul of my Codes in that little extra bit of stiffness. Everything else about the feel is familiarly Guide-like. The size of the lever blade and the initial bite are about what I already expected. Beyond that initial bite, though, I found it easier to mange the power when I was riding at speed. Slight adjustments didn’t require as much force as the Guides I knew. But when those adjustments weren’t so slight, and I was on the edge of what a trail-oriented brake is meant to handle, I found the limit to the G2’s capability is still a ways short of the Code’s.
But these brakes aren’t supposed to be Codes. In those rare scenarios when I wanted Code power out of the G2, I was on trails and at speeds that, if I were to revisit regularly, I would have Codes. When the G2s were in their element, they were a treat compared to the Guides. The Power pad compound is no noisier than the metallics I usually run, and has a pleasantly bitey-er feel. That extra stiffness makes them more predictable when I’m at the edge of what a trail brake can handle, and more comfortable when I’m not.
Again, the changes between G2 and Guide are subtle, so it would follow that the changes out on the trail are too. But it’s unquestionable that they are changes for the better. Will we be having another conversation two years from now about some yet unknown problem lurking inside every G2 brake? It’s not impossible. You could say the same about every new part that comes on the market. But the very subtlety of the refinements made to the G2 is evidence that SRAM sweats the details, and our bikes just got a little better because of it.