Introducing SRAM G2 Disc Brakes - A Guide Evolution 4

SRAM G2 Ultimate Brakes

This is our all-new, lightest 4-piston brake outfitted with every feature and material you’ve come to expect from something called Ultimate. Our engineers built it with what they would want on the trail: power, modulation, silky-smooth lever feel, complete adjustability. Our test riders dubbed the new design “mini-Code” for its Code-like performance.

G2 Ultimate Highlights

• All new brake delivering mini-Code power
• Added stiffness in the caliper
• A new pad compound that offers more bite
• The pivot bearing offers a snappier lever feel
• Offers a finger-fatigue-free ride
• SRAM’s lightest four-piston brake
• Swinglink Technology
• Reach and contact point adjustments
• MatchMaker X
• Rotating caliper banjo
• Ambidextrous levers for riders who run “moto” setups
• DOT brake fluid
• Bleeding Edge
• Accessible spare parts for rebuilds
• Weight: 242g (brake assembly, 850mm hose, with fluid)

SRAM G2 RSC Brakes

G2 RSC is the half-ton pickup truck of the mountain bike brake world — dependable, go anywhere, do anything, plenty of power when you need it, and all of the features you need. The new G2 RSC is based on the SRAM Code design, so it puts Code-like power and modulation into a mini-Code package. And, of course, the signature Guide lever-feel and contact-point adjustability ensure that this brake works great for every rider. The G2 RSC presents rider-controlled offering with an alloy blade, lever pivot bushings, stainless steel hardware.

G2 RSC Highlights

• A new pad compound that offers more bite 
• Added stiffness in the caliper
• Delivers the mini-Code feel
• Engineered to offer contact point adjustment and four-piston performance at a lower price than Guide
• Swinglink Technology
• Reach and contact point adjustments
• MatchMaker X
• Rotating caliper banjo
• Ambidextrous levers for riders who run “moto” setups
• DOT brake fluid
• Bleeding Edge
• Accessible spare parts for rebuilds
• Weight: 255g (brake assembly, 850mm hose, with fluid)

Power Organic Pad Compound

Pick the right pad for the right purpose. Metallic for aggressive, high-wear conditions. Organic — in Quiet or our new Power compound — for their respective specialties. The Power Organic compound delivers a more aggressive “bite” and increased power during sustained braking.

Pricing and Availability

• G2 Ultimate - $280 USD // €295 // £265
• G2 RSC - $180 USD // €190 // £170
• G2 Brake Pads Organic/Aluminum - $30 USD // €30 // £27
• G2 Brake Pads Organic/Steel - $25 USD // €26 // £23
• G2 Brake Pads Metallic/Steel - $25 USD // €26 // £23

SRAM G2 brakes will be available starting in April 2019.

Frequently Asked Questions

What is the intended use of the brakes?

All types of mountain biking. G2 brakes will be at home on anything from a fun, light trail bike to a race-day enduro set-up.

How did you achieve the increase in brake power over Guide?

Every part of the Guide system has been improved. In designing a new caliper, we looked to the lessons learned when we designed Code. We focused on stiffness, so the pad pocket is a little narrower and the connection points around the body bolts are larger which results in less caliper flex, which therefore provides more direct power transfer than in previous designs. We also developed our new Power Organic pad compound.

How much has the brake power increased by (%)?

Approximately 7%, but the on-trail feel is the most telling and where we see the most user benefits.

Are these brakes suitable for ebikes?

SRAM Code and Guide RE brakes are the best choices for ebikes. However, all our brakes are ISO certified and will withstand use on an ebike. G2’s 4-piston configuration paired with larger rotors will provide good performance on ebikes.

What are the brake pad compounds and their intended uses?

We developed a new, more powerful organic pad compound for G2. This pad will have a “Lunar” grey backing plate and will be available as a replacement part. Our pad offerings will include:

• New Power Organic pads – Grey backing plate
• Quiet Organic pads – Black backing plate (currently used in Guide and Level brakes). A good all-around pad. Quiet, but not as powerful as the Power Organic version. 
• Metallic pads – Copper backing plate. Our most powerful, hardest hitting pad compound. Long lasting and great in wet and muddy conditions. 

Are there any changes in the service intervals?

Service intervals are the same. All disc brakes require proper service. We recommend replacing your brake fluid once a year and replacing your brake pads when the pad puck and backer plate total thickness is less than 3mm. 

Is the DOT brake fluid the same as the brake fluid used in Guide?

Yes. We use Ravenol DOT 5.1 brake fluid 

Can you explain the reasons you choose to use DOT brake fluid in your brakes?

There are many reasons why we firmly believe DOT brake fluid is the best option for brakes:

• Higher boiling point than mineral oil systems
• DOT brake fluid manages water effectively. Absorbing water inside the brake system rather than pushing it to the edges. This helps maintain brake performance and does not allow water to collect in a brake system. Water can cause corrosion and will boil at 100C. 
• Material selection. The EPDM seals we use have a much broader operating temperature range than the buna rubber (NBR) used in mineral oil systems. This temperature range isn’t just for sealing, but for elasticity.
• DOT brake fluid allows the caliper seals to behave more consistently at varying temperatures. Meaning SRAM brakes can have a large amount of pad roll back and consistent lever throw. These seals also maintain performance when the temperature of the brake is high. 
• DOT brake fluid has a higher bulk modulus than any of the variety of mineral oils used in bicycle brakes. DOT brake fluid compresses less than mineral oil at the pressures found inside of a brake. That means mineral oil systems may have a softer feel than DOT brake fluid-based systems.
• DOT Brake Fluid can be cleaned off a bike or brake with just water. Mineral oils are “sticky” and require a solvent to remove.
• DOT and Mineral oil should be handled the same way – wear gloves, catch, and recycle.

When Guide was introduced you increased the pad spacing to allow for more airflow and better heat management. Can you explain why you have reversed this now? 

During G2’s development, we continued to test calipers and refine our convective cooling. The G2 caliper still employs the concepts we introduced with our Guide S4 caliper whereby the pad pocket is wide open, fully exposing the brake pads, and the pads stand away from the caliper allowing for cooling between the pad and caliper. 

Is the heat management of G2 better than Guide?

Heat management of G2 and Guide is the same. 

You are no longer using HeatShield G2. Why is this?

Phenolic pistons are used throughout our line, eliminating the need for a heat shield. We’ve refined the inside of the caliper so aluminum pistons are no longer needed. The aluminum piston conducted heat into the caliper, removing them eliminates the need for the heat shield.

Is there a difference in power output on standard rotors and two-piece rotors of the same size?

Power is similar between these two configurations. Our CLX rotors were designed to save weight. Our one-piece CenterLine rotors do a better job managing high temperatures because they are heavier.

The hoses on G2 are different from Guide. Can you explain the reason for changing and what the advantages are?

The new hose is less prone to holding a shape, allowing for easier installation and a cleaner look. G2’s hoses have a matte appearance as the result of a change in the outer sheath. 

What are the main differences in the new G2 caliper from the S4 caliper?

The G2 caliper has all-new caliper machining to refine control of seal/piston/caliper interface, which results in some great benefits. It’s easy to align the caliper by having an improved pad gap. G2 brakes have a consistent bite point as the pad gap remains the same as pads wear - this means the lever will hit at the same spot throughout the life of a set of brake pads. The caliper is also stiffer which increases braking power. 

How has the piston square seal changed on G2 and how does this help with more consistent and increased rollback?

The square seals remain consistent, but the way in which they are held in the caliper has evolved. The gland which contains the square seal within the caliper controls how far the brake pads move and when the pistons slip past the square seal to advance the brake pad toward the rotor as the pad wears. We’ve refined the gland in the caliper to make a best-in-class brake with respect to these critical aspects of brake performance. 

Has the brake fluid volume increased on G2 over Guide? 

No, it is the same as Guide.

Can you explain the differences in the lever from Guide to G2? Is the lever more similar to Code?

The leverage ratios of Guide, Code and now G2 SwingLink brakes are all the same. We tested a variety of new curves during G2’s development but deliberately used our current ratios. The leverage rate defines our on-trail feel, and that’s important.

We refined the small parts and assembly approach of G2 RSC to reduce the cost and bring contact point adjustment to more riders. G2 RSC features a new pivot dowel and bushing that provides a laterally stiff connection for the lever blade with minimal deflection at the tip. G2 Ultimate improves on all of this by incorporating lever pivot bearings and a carbon blade.

Is G2 compatible with current Guide brake pads?

The pads are the same for Guide and G2. With G2 we also introduced a new pad compound, the Power Organic compound. 

Are the pistons still phenolic pistons, and are these used on all G2 brakes?

All G2 brakes are equipped with phenolic pistons. We choose phenolic because it is an excellent insulator and we can control the surface finish of the piston helping with set-up and pad advancement.

Visit www.sram.com for more G2 brake details.