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Seven Suspension Bike Technology: Balance Control System

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Seven offers a wide range of suspesnion bikes. From 100 mm short travel superlight race machines to some contemporary trail bikes. One of the ways we're able to offer this range of models and ride types is due to our experience and approach to our newest suspension system we call the Balance Control System.

Seven introduced its first dual suspension bike, the Pendere, more than 20 years ago. That bike incorporated a four-bar linkage, a feature we preserve in our latest dual suspension designs. Later we offered a progressive suspension bike line with models like the Duo and Duo-Lux. For those, we collaborated with Paul Turner, the founder of Rock Shox and Maverick. Our third generation suspension design project was a collaboration with phenom Dave Weagle. Trends and technologies have moved forward over the decades, but the basics of full-suspension bikes, the need to deliver a stable climbing platform coupled to a dynamic shock absorption system, remain the same.

Seven's Balance Control System suspension project takes everything we've learned in our 20-plus years and applies it in some new ways. Seven's BCS platform incorporates that proven, classic, workhorse four-bar linkage system with our ability to customize and tailor bikes in unique ways.

The result isn't one bike, but a platform for creating the perfect bike for your style of riding and personal preferences.

Mountain bike terminology has spiralled out of control over the last 5 years with new bikes spawning new categories that overlap with other new bikes in their own new categories.

What we have done with the BCS is both simplify and yet also hold open the door of possibilities in that way we do, offering modifications and variations that let you straddle categories, personalize your ride experience, and basically create your own category.

Here, is the simplicity part: For all BCS models we offer 27.5" and 29er wheel variations. You can optimize for race width tires or larger volume tires. Geometrically, you can blur the lines between categories. We can build for 1x or 2x drivetrains.

This is Seven bringing our manufacturing capabilities, specifically our methods for customizing, to a production suspension bike. This built-to-order process enables Seven to offer more versions and options than any other suspension system we've seen yet.

Fundamentals of Seven's Suspension System

For a dual suspension bike like Mobius, our first concern is the Instant Center of Rotation, also sometimes called the virtual pivot point when using a four-bar linkage. Where you place the IC affects anti-squat and brake jack (see explanations below). Essentially, that placement should keep the brake from compressing the shock and at the same time, limit the energy lost to suspension as the rider pedals. This is about creating a stable platform for the rider within a system under dynamic stress.

Anti-Squat is the bike's ability to resist pedal bob, to keep the rider's normal pedal stroke from activating the suspension. Anti-Rise is the bike's ability to resist brake jack or braking effect, to keep braking force from compressing the shock. These are oppositional forces, obviously. Complicating the picture is that the bike's anti-squat and anti-rise characteristics change based on drivetrain gear ratio.

Pedal Kickback, also called chain growth, is the process of the rear wheel's axle path moving away from the bottom bracket during shock compression, which increases the chain's length.

Progressiveness is the extent to which the suspension gets stiffer as it progresses through its travel. Mobius is neutrally progressive, which means it has excellent small bump sensitivity, i.e. fast micro-adjustments, and plush big hit absorption. Mobius doesn't over-correct. It reacts in small ways to smaller forces and in larger ways to larger forces.

Elements of Design that Affect Seven's Suspension System

Many design considerations address the challenges that get our suspension to that place of perfect riding balance:

Suspension Specific Elements

  • Four-bar linkage
  • Kinematics
    • The location of our four pivots
    • Shock travel leverage ratio
    • Chain force vector and chain tension
    • Axle path
  • Shock System
    • Progressiveness
    • Shock travel. Suspension travel: 100 or 120 mm
    • Floating shock
    • Trunnion mount design
    • Shock type and settings
  • High quality bearings (not bushings)

Non-Suspension Features

  • Titanium front and rear
  • Custom geometry
    • Center of gravity
    • Wheel size
    • Contact patch location front and rear
  • Solid aluminum block rockers
  • Component choices

Individually, no one factor above makes a massive difference to the suspension character of the bike. That's why stock bikes can get away with being non-optimal for a given rider. But, stack all of these together and you get a finely-tuned, optimized bike that will make a difference on the trail. That's what makes BCS, and the Seven bikes built around it, something really unique and not previouslly offered in the market.

To learn more about the technical aspects of Seven's suspension design, read our Virtual Pivot Track information. This is where the good stuff happens.