Tom's Pro Bike: Mountain Bike Monday - SPECIALIZED BRAIN SHOCK

Today we are going to go a little technical and discuss the Specialized Brain Shock and it's purpose for your bike!

The Inside Line - Brain

WHAT IS THE PURPOSE OF BRAIN?
Competitive riders want to go as fast as possible. Up, down, pedaling, coasting, on smooth terrain or bumpy and rocky terrain. A full-suspension bike can absolutely benefit the rider when going fast over rough terrain, but most shocks have to be tuned on the fly to adapt to pedaling vs. bump forces. The purpose, and beauty, of the Brain is that it is the only shock that can tell the difference between rider and terrain inputs, and automatically adjusts accordingly to allow the rider to focus on one thing: going fast!

HOW DOES IT WORK?
Inertia valve held in the open position (with thumb). Above it is the main compression valve. Hitting a bump will open the inertia valve and allow oil to flow for smooth suspension action.The Brain is similar to a normal shock in that it contains oil, compression & rebound circuits, an air canister, etc. Its unique ability to separate rider from terrain (pedaling vs. bumps) inputs comes from the reservoir near the back axle (similarly, in the bottom of the Brain fork leg) that holds the inertia valve. The valve is oriented to cover the main compression port while the rider is on smooth terrain, keeping the suspension firm. Because of its location and design, an input from the rider (like bouncing on the saddle or pedaling) will not activate the "bump" circuit of the suspension. Conversely, the wheel hitting a bump, like a rock or log, will displace the inertia valve and instantly allow oil to flow for smooth, controlled suspension action.
The Brain also has a unique feature with the blue knob, called the Brain Fade. This adjusts how much oil is allowed to flow around the inertia valve while on smooth terrain, and allows the suspension to move slightly when not hitting a bump (like setting sag for instance). For a firmer setting, turn the Brain Fade clockwise while you can have a slightly softer feeling on smoother terrain by opening the Brain Fade counterclockwise. This setting is a matter of personal preference; riders are encouraged to find the setting which best suits their style. Once the rear wheel strikes a bump, the Brain Fade setting will not affect the suspension actuation.
It's important to note that the Brain is not a lockout. A lockout completely eliminates oil flow, resulting in no suspension movement or bump absorption. The Brain has a free bleed system that allows oil to bypass the inertia valve. This allows the bike to settle into its sag point on any Fade setting, and prevents the system from locking up. The new Brain shock is tuned to better track the terrain and improve small bump absorption.

CHANGES IN THE BRAIN (FORK & REAR SHOCK) FOR MODEL YEAR 2014
As we have learned more from riding and racing with the Brain, we have evolved how it functions. The major lesson- a harsh feeling bike is not necessarily the fastest bike. Having a bike that can accelerate quickly and maintain that speed (or momentum) is faster. so the Brain has been retuned in two major ways.
1. The threshold, how much force is required to open the inertia valve.has been reduced.This smooths the transition from closed to open and back to closed, almost entirely eliminating the potential loss of momentum in that transition.
2. The mid and high-speed circuits have been greatly improved for better damping throughout the travel range.
* As a result of these two improvements, the latent effect is a weight savings of an additional 25 grams from the MY13 Brain.
For example, on the older shock a rider would hit a bump and feel a slight "thud" or knock as the Brain opened before it pushed through more travel than was needed. In that situation. the platform felt firm while not hitting a bump and then a bump would soak up most of your travel. Now for MY14.a smaller bump force will activate the Brain (a lower threshold) and the shock will hold the rider through the travel more effectively (better damping through the range). This means smoother transition from a firm to open Brain, and more support in the travel range to hold momentum yielding more speed.
This will feel different than the previous Brain as the suspension will feel more active. Remember that going fast is all about accelerating UP to speed and then HOLDING that speed. This new Brain tune will absolutely let you go faster. but will not feel as firm. Remember, the Brain was never intended to be a lockout.
TIPS, TRICKS, AND GOOD THINGS TO KNOW FOR SETUP
• The tune on the Epic vs. the Epic World Cup is different, with both shocks having the new lower threshold tune, with the World Cup the firmer of the two.
• The adjustments of the Brain Fade are easier to work with as the shock and fork now have 5 positions (4 clicks) each, and are matched up to balance the front and rear end of the bike (except on the Stumpjumper HT. which only has a Brain fork).
• The bottom-adjust Brain (Expert models) has the lighter threshold tune, but still retains the higher number of clicks.
• Think of AUTOSAG as a bonus piece to your shock: it is helpful but you do not have to use it. You can sag a shock or adjust the air pressure the old fashioned way. • If you are going to use the AUTOSAG on the Epic. the shock MUST be pumped up to 300psi. no matter the weight of the rider.
CONCLUSION- WHY IS THIS IMPORTANT
From the introduction of the Brain in 2003, the goal of allowing the rider to go as fast as possible while pedaling, hitting bumps (separately or together) has never changed. We will continue to mate our shocks to our FSR linkage and make the fastest bikes on the trail. remembering that ultimately, smoother is faster.
May your climbs be swift and painless, your descents as fun as ever,
The Hyper Performance MTB Team

If you think you want to learn more about the Brain and the bike that carries them around stop by the shop and check out our inventory of Specialized Mountain Bikes!