Decree Design and Engineering

Bar_01

Felt’s team of mountain bike engineers designed several versions of the Decree to ultimately create the final frame. From shock tuning, to stiffness testing to carbon selection, the engineers spared no expense in perfecting every detail of the Decree.

FAST SUSPENSION

FAST, or Felt Active Stay Technology is used on this frame to provide efficient pedaling, lighter weight, and increased stiffness.

FAST EXPLAINED

Efficient Pedaling: In order to provide efficient pedaling, FAST relies on both ideal anti-squat values as well as the flexible carbon stays.  As the suspension moves away from the sag point in either direction, a force is created from either compressing or extending the stays.  This force acts on the shock and helps return it back to sag.
This provides a stable, responsive platform for pedaling.

Large Impacts: Support for large impacts is provided in two ways: decreasing leverage ratio and carbon flex.  The leverage ratio is decreasing which makes it progressively harder to compress the suspension as it moves through the travel.
The carbon stays add to this by contributing an additional spring force as they are extended through the travel.

Small-Bump Sensitivity: At the top of the shock stroke, the stays are in a compressed state which pushes the shock toward the sag point. This reduces the force required to initially compress the shock and softens the initial part of travel. Additionally, since the pedaling performance and large impact support are controlled with the linkage, the shock can be run with minimal compression damping. This frees the shock up to remain active and absorb the smallest of bumps.

Long, Low, Slack Geometry

The geometry includes a long front end, low bottom bracket height, and slack head angle for maximum control at speed and in steep sections. This geometry provides stability and confidence at high speeds.

Lowered Seat Tube Geometry

The seat tube pivot is around 20mm lower than on previous models to allow for more seat post insertion on the smaller sizes. The seat tube lengths have also been made shorter to allow more clearance for the mechanisms on dropper posts. With this option, riders have a wider range of fits on the bike.

INTERNAL CABLE ROUTING

The cables are all internally routed with an entrance at the head tube and an exit near the bottom bracket. Both sides have removable plugs to fit Di2, shift, or brake cable that can be configured to suit the rider’s needs. These features result in a clean, snag-free design.

Removable Front Derailleur Mount

The front derailleur mount is removable in the event the rider is using a single chainring. It can be replaced by a blanking plate to fill the void that is left. This delivers a clean appearance for riders choosing to run a one-by (1x) drive train.

Flip Chips

The geometry can be adjusted by rotating eccentric chips located in the seat stay pivot. By changing the orientation of these chips, the bottom bracket height will be raised or lowered by 10mm and the head angle will be slackened or steepened by 1 degree. The adjustable geometry allows riders to personalize the Decree to unique riding styles.



THE DECREE DEVELOPMENT CYCLE


Bar_01

Verdict

Verdict

STEP 1

The “Verdict” was the first prototype that engineers made of this new trail bike. It started as a way to explore the emerging 27.5” wheel size. They took an existing Felt 29″ Edict alloy cross-country bike and modified the frame to fit around the smaller wheels. This resulted in a linkage driven, single pivot bike with 27.5” wheels and geometry close to that of the final Decree. Internally, engineers gave this bike the code-name “Verdict” because it was an Edict platform that was transformed into a bike that was more similar to a Virtue, Felt’s 29” full suspension mountain bike.

The engineering team was so pleased with the pedaling performance that they ultimately decided to use the FAST suspension platform to best achieve the goals of this bike. The engineers also gave this new bike an official title of “Decree.”

Verdict

Alloy Decree

STEP 2

The Decree alloy prototype frame was the first test mule for the Decree platform. It was designed in-house by Felt engineers and used existing tubes from other bikes as well as CNC links and parts to connect the tubes.

The purpose of this prototype was to verify the hard points such as frame geometry and pivot points. The frame was tested by Felt staff as well as sent out to professional athletes for feedback. Coincidently, the frame was welded with a slacker head angle than intended (67 vs. 68 deg). This turned out to be positive for the test riders and the designers made the decision to go with the slacker 67-degree head angle.

Verdict

3D Plastic Test

STEP 3

Although not technically a ride-able sample, the 3D printed model is a very critical step. It allows engineers to install parts and adjust them as if they were on a bike. It is difficult to get this level of fitment in CAD. If any clearance issues are discovered, engineers can make adjustments to the CAD model before committing to carbon molds.

Carbon Sample #1

Carbon Sample #1

STEP 4

This first carbon sample was where engineers first see how the bike performs. The engineers conducted stiffness tests on the frame as well as test rides and it was on par with the stiffest bikes they have tested on their fixture.

At this point, the team also began work with RockShox on a custom shock tune. Felt engineers spent two days testing on the trails in nearby Laguna Canyon to find a shock setup that best complemented the frame. Additionally, after that tune was determined, the bikes were sent out to Felt pro athletes in California, Oregon and Europe who confirmed that tune was spot-on for global conditions. This ended up being a shock with a relatively low compression tune and high air volume. When paired with the progressive nature of the frame and flexible carbon stays, this resulted in a bike that pedaled extremely well, could withstand big hits, yet was still able to remain active to absorb small bumps.

Carbon Sample #1

Carbon Sample #2

STEP 5

Although it looks nearly identical, the second carbon sample saw several small refinements from the first sample that greatly improved the performance. The flip chips were updated, seat post insertion was improved, transitions between some of the tubes were smoothed out, and the carbon layup was refined. These small changes resulted in a frame that was 10% stiffer than before while increasing durability for the rider.

Carbon Sample #1

THE FINAL PRODUCT

STEP 6

Following the second carbon sample testing and refinement, the final Decree frame was finalized and prepared to go into production. The final Decree frame encompasses all of the ride qualities the design team wanted: stiff, light, agile and confident. The Decree offers the ultimate trail bike with adjustable geometry, all-conditions capabilities and an overall outstanding ride experience.

PRINTABLE WHITE PAPERS

CLICK FOR DOWNLOAD