The aim of the Switch9er FS was to design and manufacture in house the most well engineered playful natured, confidence inspiring, aggressive 29er full-suspension frame. We have a bit of form for this: Also taking inspiration from our Sherpa 29er that has the agility of a 26” wheeled trail slayer. It is the evolution of our Switch range. Holding the same aggressive intent as our award-winning Switchback and our popular Switch9er Ti.
When designing our Hardtails one of our most important considerations is how the frame supports lateral stiffness. Bracing the torsional stress generated via the riders pedal strokes and weight when cornering, offers a much more instantaneous acceleration, as none of the riders energy is wasted in lateral movement. This consideration then naturally fell into play when designing the new full suspension frame as there are, with suspension design, even more reasons to design out lateral Flex.
One of the major issues can be lateral load on the shock unit creating stiction, resulting in improper shock function. Lateral load also causes added stress and wear on bearings in bushings and gives inconsistent bike handling too, which well, sucks big time!
In order to keep the design aesthetic and performance in line with the other models in our range, we decided to go with the steel front triangle off our Stiffest Hardtail, the Switchback. The Triple-butted Reynolds 631 DZB seamless, air-hardened down tube, and top tube and custom butted Reynolds 631 seamless, air-hardened seat tube works beautifully to dampen trail buzz, while offering good lateral stiffness.
In the design process careful consideration was taken in the lateral bracing of the frame. One of the first areas that we considered was the bottom bracket. The bottom bracket shell and first lower link pivot shell is one ‘Egg’ shaped fully CNC’d Steel peace, currently referred to as quite simply “The Egg”.
Knowing that aluminium has been used in full suspension design for a long time, the aluminium rational of ‘stiff and light’ works brilliantly for Full Suspension mountain bikes and has been proven iteratively over the last 20 years. For a suspension unit the ideals are: stiffness to maintain geometry and power transfer, and lightness to reduce unsprung weight. Unsprung weight is the weight of any parts that support the wheel to the main frame before the shock.
More compliance, more small bump absorption, quicker rebound and places far less load on the shock damping internals, so it can run less damping, reducing heat and improving shock consistency over a long run down the mountain. So the lighter and stiffer the back end the better!
This is why we use fully CNC’d 6082-T6 aluminium linkage parts, the top one being linked via another Steel CNC’d part that nestles in and is welded in to the ‘top tube’ and ‘seat tube’ juncture, offering a 300mm bracing section from an already well braced bottom bracket and the first pivot part.
We then further designed out lateral stress by using two CNC’d 6082-T6 aluminium ‘Dogs Legs’ either side of the seat tube, connecting the two linkages together as the contact points for the rear triangle sections, which runs four custom drawn 6063-T6 aluminium tubes to meet our custom designed Switchback dropout swap-out system.
We’re all keen riders at Stanton, with an extended family of racers, freeriders, hardtail hooners, trail centre smashers, dedicated podium chasers and recreational riders who just love being outside in the woods on their bike. After debating all the available options we decided to set some principles to help decide the way to go. The bike must have exceptional ride characteristics, no compromise. The decision of running a super sleek steel front end also meant we wanted to keep the shock mount as clean as possible, so we decided that we wanted to drive the shock load up the down tube rather than smashing into it, which would require lots of additional weight and would look a bit ugly too. Plus we wanted to leave room for a water bottle in the already compressed front triangle.
This led to the decision to mount the shock parallel to the down tube. As previewed on the Ali framed bike we teased many moons ago now! After considering all the above and the suspension systems we decided to design our own set up that would meet our design principles; a unibody rear triangle comprising of two one piece sides bolted solidly to the CNC link pieces which creates a super stiff and light structure to drive lateral stiffness and minimise weight.
The suspension unit is then attached with a dual linkage to the front triangle that forms the basis of this design as we felt the more complex and technical suspension arrangement would reap benefits out on the trail. Also the novel arrangement will put the shock loads where we want them and aid manufacture as that’s been a key consideration throughout the project and ultimately it looks badass too!
Mike Jersey Taylor on the Switch9er FS
Switch9er FS – Size testing in the Alps
- Reynolds 631 44mm head tube (fits all steerers), gusseted down tube and our super-sweet alloy head badge.
- 30.9 Stealth dropper-compatible seat tube (34.9 clamp) with internal routing round the BB and into the down tube.
- Triple-butted Reynolds 631 DZB seamless, air-hardened top tube, and down tube and custom swaged and butted Reynolds 631 seamless, air-hardened seat tube. Takes full-length gear outer for consistent, weather-proof shifting.
- Fully CNC’d linkage pieces
- Fully CNC’d bottom bracket shell and first linkage piece known as “the egg”
- Heat treated super short aluminum chainstays 445mm
- Custom CNC’d Swapout dropouts 12 x 148 Boost as Standard
- 15″ frame weight – 3.95kg without shock, 4.47kg with shock
- Frame designed around a Q factor of 172mm or greater
- 1Designed for a headset cup depth of 9mm
- Recommended Fork Travel: 140mm - 160mm