The Hex AM is without doubt the one bike that has had more man hours put into it that all out other bikes put together. The combination of both being our first FS design and the care we’ve put into making the Titanium behave exactly how we want it to with our suspension platform have literally burnt hundreds of hours.

This continuous development process can be seen in the evolution of our pivot links, and how they have evolved through testing from first draft alloy to carbon production versions, I’ll hand over to Dean the designer now to tell the story.

What you see here in front of you is the first gen link set, or the prototype. The job of the prototype is to ensure adequate movement, clearance and fit. These should be designed to fit your image for the end product, as testing will be more accurate in the long run. In an ideal world your proto parts would test 100% and continue on to production but for us that wasn’t the case.Once installed we discovered there was a lot of torsional flex particularly in the upper link (left) so it was back to the drawing board to make our second revision.

Our solution to the flex issue was to relocate the bridge. The bridge was far too close to the front triangle, so it had little effect on stiffness. The two arms were free to move independently of each other in a scissor action. By moving it closer to the rear triangle pivot and widening it we cut the flex down to almost nothing. These links are so strong that the only discernible flex is in the frame parts themselves. In addition we reduced the relieved section in the lower link to 4mm as opposed to all through, tightening up the lower pivot as well.

Now the links are perfect, ready for production but there is a bigger problem: cost. The cost of these links are between $215 and $230USD each. Factoring in the cost for the mounting hardware and frame parts, the project was unfeasible. We slaved over it for a few weeks trying to figure out how to cut costs. The easiest way would be to manufacture in bulk, but for a micro company like ours it’s impossible to justify buying 1000 sets when you might only sell 25 in a year. Right when we were ready to call it quits and shelve yet another project, the answer came to us from the most unlikely of places. That answer was carbon.

Now that sounds funny right? Carbon is expensive, elitist, why the hell would that be the answer? The reason Carbon is cheaper is because you only need to manufacture the mold once. You cop a higher startup fee but save in the long run as the retail price can be dropped by a whopping $400USD per frame. Instead of spending $200 per link we are now spending about $60. Add in Carbons high strength to weight ratio and it’s natural stiffness and you’ve got a winner. In addition we’ve beefed the bearings and axles for the upper link from 22×10 to 28×15 to bring it inline with the lower pivot and removed the relieved section altogether. Preliminary tests show almost doubled strength and stiffness, with a 40g reduction in weight over it’s Aluminium counterpart.

Suspension. Ever since the early 90′s, when those first smart individuals decided to strap a spring on the front of their bike, we’ve loved suspension. As a collective we’ve strayed off the path at times (need I mention the huckmasters of the late 90′s/early 00′s?) but we’re doing all right. Then it got complicated…. too complicated.

I’m talking about ABP, FSR, DW, VPP, Smoothlink, A.R.T, Maestro, the list is endless. It’s all marketing bullshit to hide what is really going on. Now I’m no self confessed suspension aficionado or anything but I know enough to get me by, and I’m going to tell it how it is with our newest and first suspension design, the Hex. 

 Note: This is by no means a definitive guide, It’s a brief explanation covering the main attractions of our design. I could go on about the process from concept to reality but I guarantee your head will explode. We here at Kingdom pride ourselves on our patience and mental fortitude against the almighty no.

At first glance you’d say ‘That’s a DW Link’ but you’d be wrong. Yes it looks similar but it doesn’t meet the specific criteria to classify as DW link, as the Instant Centre isn’t positioned between the two lower pivots at bottom out. Pretty simple stuff hidden underneath a mountain of engineering lingo.

Now this mess of lines is the Instant Centre. The Instant Centre is the intersection of the centrelines through pivot points. 2 Points, green at 0% travel and yellow at 100% travel, mark the extremes. The red line is the path of the Instant Centre. Now what does this mean? quite simply decent pedalling. From what I can gather (I could always be wrong, feel free to correct me below) the Closer the IC is to the main Pivot, the better it pedals. This is why the IC for DW travels through the main pivot low/mid travel.

Now that we’ve covered that, we’ll talk about Squat. Squat, or Anti Squat, is the bikes ability to handle suspension bob when weight is shifted backwards (such as climbing a hill or a takeoff under power. Squat is measured as a percentage, with the ideal value being 100%. Less than 100% and the bike bobs down in it’s travel, more than 100% it extends. If this value drops into negative figures you get pro squat, which basically means it sags like hell and is totally pro according to Specialized. (Note: I ride a Demo so I’ve experienced this for myself)

The easiest way to explain this is with geometry. We’ve got the pivot/axle centreline in red, and the chain in yellow. If angle A=0 degrees, then we have 100% squat. If angle A is positive (like above) then we have a 100+ squat, or extension under power, and if the angle is negative (measured from the crankset end) then we have compression under power. Think of a ruler, if you hold it horizontally pointing away from you and pull on the free end horizontally towards you it doesn’t want to move, but if you tilt it up 45 degrees it pulls towards you easily. Same principal. The aim is to have 100% squat at or just above the sag point for best pedalling efficiency. Note this is a very barebones explanation, there are a lot of other variables involved.

We’ve designed the Hex primarily around an air shock, in this day and age of weight weenieism, it seemed like the best choice, but it will also work with a coil shock. It has a progressive shock rate, meaning as the bike travels through it’s suspension it will get stiffer, providing protection against hard bottomouts. It’s best to decide what kind of shock you are planning on using early on because this will determine how you manipulate the shock rate. Air shocks are naturally more progressive in the high travel range, as the last third of compression the air is compressed exponentially, whereas a coil shock has a liner progression, meaning for every X mm Y force is applied (that’s why they are graded in kg/mm or Lb/In).

Ideally you want your shock rate to drop off in the last third of travel to counteract the extra compression required for air shocks. Failure to do so can lead to a very harsh and unpredictable top end that can’t be dampened without ruining low end travel.

Perhaps the most important bit of advise I can think of is: Think about your design. Don’t do it simply because it’s never been done, there’s probably a very good reason why. I’ve spent my time trying to come up with something groundbreakingly new and come out with nothing but crap. That’s not to say you cant try, just make sure the numbers back it up. Thinking about what material you plan to use and your budget is a good starting point, as you might not be able to afford to machine those 35 links after all. Always refine the looks around the design, not the other way around.

So there we go. That’s pretty much it. With a basic understanding it’s not all that technical, you’ve just got to problem solve to get it all to work together. Keep in mind clearances and materials, especially where moving parts are involved, as the best suspension design in the world could be undone by flex and impracticality. Also check out any relevant patents to make sure that you aren’t going to get sued out the wazoo.