Seven Design Philosophy – Understanding Chainstays

Seven Cycles offers a variety of chainstay styles, each with their own unique features and benefits. Our most popular designs include our Inline stays and Chopped stays.

The popular perception is that chainstay length is one of the most important factors in bike design because stay length affects bike handling, acceleration, climbing ability, and descending stability. While it’s true that chainstay length has an important impact on all those aspects of a bike’s character, stay length is only one factor in more than 200 design parameters that go into developing an ideal bike.

Anytime we put too much emphasis on one design element at the sacrifice of others, the result is a sub-optimal riding experience.

Read THIS for a deep dive on Seven’s design philosophy for optimal chain stays.

The Four-Season Sola 2×2

Design Mission: Create the most capable four season bike possible. As cyclists we are keenly aware of the weather and the many challenges it presents. Any cyclist who lives in an area that experiences four true seasons, like our home here in Massachusetts, will want a bike capable of tackling whatever the weather throws at them.

After building about a dozen variants of a year-round bike, we packed all our experience and research into this one broad-use, high-capability bike.

For summer and fall, with 29er mountain tires, the bike is a fast and agile race-ready bike, setup for technical single-track and short, punchy climbs. In the winter and spring, with 27+ 3” tires, the bike can do anything and go anywhere, with or without studs, in snow, ice, mud, or frozen terrain.

See more photos and read all the details here.

 

The Sevenduro 2×2 Scrambler

Well, that’s a mouthful, but it’s a bike with a LOT going on. The basic idea with this project was to build a massively versatile machine that can maximize performance across a range of ride types. The knock on some multi-purpose bikes is that they’re not great at any one thing. The 2×2 Scrambler aims to be great at many types of riding.

Here is what it’s for and how we optimize for each thing.

For this specific design project we optimized for these two distinct ride functions:

  • A bike ideally suited for fast gravel and dirt road riding in hilly terrain (Sevenduro mode)
  • A bike optimized for New England mixed terrain riding: sections of singletrack with equal sections of paved roads — and a bit of everything else thrown in (Scrambler mode)

These two bikes are very different in function, and therefore design. How do you get this to work? Beginning with tire choice and wheel diameter decisions, the optimal design produces a frame geometry that allows for versatile rider position, fine tuning for each type of riding.

With this Evergreen 2×2 we have two hot-swappable modes. The first configuration is a pure gravel riding setup for the 700c wheels, we call it the Sevenduro Mode — because it’s designed for endurance gravel rides. It’s lightweight and provides a perfect gravel balanced rider position.

For the second hot-swap configuration we’ve optimized for 650b riding. We’ve tagged it the Scrambler Mode — named after a type of bandit off-road motorcycle race. The Scrambler Mode has a flared drop bar for better trail handling, wider grip stance for more control, a shorter stem for slighter reach and improved body language control, and slightly higher front end to facilitate rolling over logs and other adventure obstacles.

There is a ton of new tech in this bike, features that make it a great travel bike, a worthy race bike, an all-weather commuter and adventure rig. Read more on the specifics here.

The Seven Ultimate Axiom Disc

This is the Seven Ultimate Axiom Disc, a project bike we developed as part of this season’s focus on technology, innovation, and leveraging the experience of building more than 30,000 custom bikes. For this particular project, the design goal was build the fastest, lightest, no-compromise road disc bike we could. As a result, this bike introduces a slew of new features that are available in our mainline products starting immediately.

Here is a quick look at just a few of those features:

One-Inch Fixed Chainstays  – Larger diameter tubes, with thinner tube walls, increase both bending and torsional stiffness by 32% over our 7/8″ stays. We hold the weight down by custom butting the tube stock in house. Read more here.

Asymmetric Fastback Dropouts – 75% stiffer than the most popular titanium thru-axle disc brake dropout on the market. These custom asymmetric  dropouts save 60 grams of weight over our conventional disc brake dropout system. Read more here.

3D Traction Seat Stays – With 3DT, we’ve been able to improve rear tire traction without reducing frame stiffness. We achieve these traction improvements through a combination of more aggressive bend profile, bending in multiple planes (3D), and a new tube butting process. What you get is a seat stay with a more dramatic shape that dissipates multi-directional force, and minimizes weight. Read more here.

Synergetic Chainstays – When you introduce asymmetry into a frame design, you have to restore balance. Our Synergetic Chainstays serve this function. Their unique design allows clearance for full-sized chainrings and 28c tires. They let us run a sub-41cm chainstay with a 160 mm disc rotor. Read more here.

Active Race Design Geometry – ARD geometry is a combination of race-specific elements that provide quick handling and telepathic transfer of rider input to your tire contact patches. We achieve this through a combination of frame geometry modifications including a compact wheelbase, short chainstays, high bottom bracket, steeper head tube angle, tighter front center, more compact front triangle for faster reaction time, improved front end torsional stiffness, and a bike that’s easier to throw around in a shoulder-to-shoulder pack of riders. Read more here.

All Out Speed Kit – Where Seven’s Active Race Design geometry option is a comprehensive set of geometric adjustments, the All Out Speed Kit modification is a set of design features that improve race performance and placing. Our most popular titanium AOS Kit includes our One-Inch Fixed Chainstays, an oversized down tube, a T47 bottom bracket, a Max Power Seat Post, Slipstream Di2 Internal Wiring, and a 44mm head tube. Read more here.

Direct Mount Derailleur Hanger – This is the industry’s first titanium direct mount hanger for Shimano rear derailleurs. About three times stiffer than a typical aluminum hanger, and tough as nails.​​​​​​​

The King and Us

We (and our customers) are in the very fortunate position of being able to choose what parts we put on our bikes, so it’s no surprise that we choose to work with companies who share our passion for quality, durability, and simplicity.

Chris King Precision Components has made bicycle components since 1976, focusing on those same principles. Like us, they take a ground up approach, engineering and manufacturing their own bearings, specifically for bicycles, right in their own factory.

Over the years, we’ve seen their headsets go from frame to frame. We’ve seen hubsets survive jarring crashes and seemingly intolerable conditions. These are parts that have carried their riders to   Tour de France podiums and World Championships in the dirt, but they also go on Sevens every day. We are proud to work with Chris King and put their headsets, bottom brackets and wheelsets on our bikes.

When you make good things for people, things that last, they reward you with loyalty. King has earned that sort of loyalty over their 40 years in the bike game. A touch of color pressed into a head tube or that distinctive angry bee hub sound lets you know you’re riding with a King devotee. It’s a loyalty born of those bedrock beliefs in value, quality, and performance, values we share and deliver with every bike.