Review: The KINGDOM HEX AM275 Titanium Enduro Bike
It all seems to be all about carbon nowadays, everyone who has a bit of coin and wants to go for the more bank busting, high spec frames are opting for this trick looking, light-weight material over heavier alloy or even steel frames. So in this weight obsessed bike market, what other options are there?
In days of old, XC riders loved using titanium fully rigid bikes as the material is more forgiving, offering a softer ride. The old rule of thumb for titanium is that it’s half the weight of steel but the same strength, plus it won’t shatter like carbon. The down-side being it’s much more expensive to buy and to work with.
On first appearance this bike is a real stunner, with beautiful seamless welding and shiny, almost stainless effect tubing. It is bang on the mark on the weight front, this build coming in at 29lbs (13.15kg) with pedals and tyre gunk, it doesn’t feel real light, but nor does it feel heavy (frame weight 3.15kg 6.94lbs). I’m guessing with the Ti build it could have been produced with thinner tubing to get the weight right down to a silly XC feel, but flex then could have been an issue. When this thing arrived, flown direct from Kingdom’s base in Denmark, the first action performed was the basic flex test. This involves standing to the side of the bike, left hand on left grip, right hand on saddle, right foot on the bottom bracket and give it a good leg push! Amazingly it felt as rigid as hell, on close inspection I realised this was due to the rear triangle being one complete welded piece and the linkage plates (being the only pivoted parts) being made of carbon (alloy plates also being an option), this seemed like a crafty way around the flex. This model came with the new X-Fusion Sweep forks and O2 RCX shock. The overall look of this bike is real subtle, with no blingy looking parts, but the attention to detail seems spot on. This thing really is made with Enduro type racing/riding in mind, not front derailleur compatible, nice slack 66.5 degree head angle, 336mm BB height and long 612mm top tube (in large).
The ride of the Hex is so noticeably different from the moment you start moving, it’s just so silent and plush, it’s like some super computer is working away every millisecond, smoothing out every bump. Although the sideways flex has been eliminated the elasticity of the titanium is so noticeable, and the faster and harder you push, the more it seems to soak it all up. On the ups I have to admit it didn’t seem any better that any of its alloy Enduro-style cousins, just along the same lines really, but the fantastic 4 click pedal efficiency adjustor of the X-Fusion shock and total lock-out of the forks was very helpful on the climbs. On the first ride the front end felt too low and quite long, and with the front of the top tube sporting a very unique bend, the front shifter stopped the bars from turning full circle, tapping on the top of the frame. All issues were simply addressed by swapping the spacers from the top to the bottom of the borrowed proto 40mm stem, then it felt right and ready to nail those trails.
On the downhills, right from the word go this bike is simply amazing, it feels like you just can’t go fast enough to unsettle the ride. I was truly thrilled by the big hitting capability of the X-Fusion suspension, working in perfect unison front and rear, with the titanium just soaking up and smoothing out everything thrown at it. It really is in a class of it’s own once the going gets gnarly and fast. The low BB height and slack head angle allows you to feel real comfy on the steepest of descents.
I caught up with Chris from Kingdom to as him some questions about this rare top shelf trail weapon.
So why titanium?
I could go on about a love affair with titanium since I was 15 or the magical ride characteristics of ti, but the reality is this bike was designed as a 27.5 carbon frame, we had so many problems with our carbon factory in China that we pulled the plug after the first moulds as we didn’t feel comfortable with the quality. So we converted the core elements of the carbon design into a Ti version, which became the Hex. We’d worked with Ti for about 6 years on our hard-tails, so it was more of a comfort zone thing, as we knew more about the stresses and how titanium reacts under different loads. Initially the plan was to make a proto-Hex, just to get proof of concept on the suspension platform, but the initial ride was far better than we could have imagined, so we put it into production, also so we could have some titanium FS frames to ride, and then people saw it and seemed to like the idea.
How long was this bike in the making, from the idea, to the finished product?
If you include the original carbon design development, it feels like an eternity, but the reality is 3.5 years. When we started there was no other production 27.5 frames, only one off custom designs and nothing with suspension.
Before you were established in 2007, what other bikes influenced you, i.e. for the ride, angles, etc?
The bike I was riding and loving around the time we started Kingdom was the Yeti DJ, I wasn’t that much into 4x or Dirt Jumping and used it for general trail riding and loved the way it rode, so the DJ played in the thinking behind some of our early hard tails.
What do you call this linkage and what are it’s advantages?
DK Link. We jokingly called the suspension this as our Kingdom designer Dean Kemp (DK) made the platform but we thought it might be a bit close for comfort. So it’s nameless and we’re not that big on marketing our bikes with acronyms.
What are the difficulties and stumbling blocks in dealing with titanium as a material?
There’s so many pre-concieved and generally incorrect ideas floating around about titanium, mostly about the flex. The flex that people talk about so much, is actually the materials low elastic modulus, which in normal speak means it has inbuilt damping, which is why it’s so good for hard-tails, as it soaks up a little of the trail shock and when used properly gives the perception that the bike has a spring and liveliness that sets it apart from Alloy, Steel or Carbon. We’d spent 6 years experimenting on our hard-tails; the Vendetta (4X) we virtually eliminated any flex but what damping was left made it burst out the gate and accelerate like crazy but with a very harsh ride and with our first All Mountain bike the Foia we did the opposite and played with the elasticity, so it was almost like a soft tail and had about as much damping as possible without flexing like rubber on each pedal stroke. Understanding the material and how it responds is the key to designing a good ti bike but it’s the preconceptions about flex that make most people believe it can’t be used on a suspension bike. If you understand how it works you can use the material to your advantage in any bike design.
Could you have gone any lighter, or would rigidity have been compromised?
It could be lighter. The original proto was lighter, but we had too much lateral flex around the chain-stay yoke and pivots. So we re-designed it with a different chain-stay, larger bearing size, larger pivot axles etc and in doing so we added extra weight. The frame is generally optimised to be as light as possible with larger internal drillings varying the wall thickness of the tubing. So for me it’s about the best balance of weight to rigidity to strength. Personally I wouldn’t go lighter.
Why the bend in the top tube?
That’s a good question. The proto had a straight top tube and that was how it was going to look, but the process to production took so long and I’d been staring at the design/proto so much that I’d started to ask myself self doubting questions about the aesthetics, so I sent out a couple of top tube design options to a focus group, straight or curved, this spread online and became a Coke or Pepsi challenge. Coke won so The Hex has a curved top tube. I still can’t decide if I like it straight or curved.
Just how did you eliminate that titanium flex?
The front was pretty much spot-on from the first proto, as we’d used the same tubing thickness and gauges from the Brigante (long travel hard-tail), that model has been running for about a year and does exactly what we want so we borrowed from that design.
But as I mentioned the rear was the issue, but by re-working and re-working the rear we got the ride we wanted. We played with differing configurations of tubing gauges in all stays and the thickness of tubing, positioning of supports and then redesigning the chain-stay yoke into a 1 piece all these things helped to eliminate the unwanted flex. We did all this by working in ‘real-life’ and developing the prototype with rider input rather than in computer simulations, this is why the development took so long, but I think it has made for a better production bike and a design that will run for years rather than having to iron out issues by making a ‘improved’ Hex V2 next year.
Would internal cable routing have been difficult to do with titanium?
We stayed away from it so far as personally I think it’s a less practical than external routing and would be a bit of a fad, but it seems to be here to stay and it’s quite possible in ti, so it’s one of the options we’ll probably offer if a customer wants it.
Any other models in the future, 29er?
We have a design for this in 29, but in the past we’ve let our enthusiasm for ‘the new’ throw our limited budgets into chaos, so we’re trying hard to stick to the Hex 27.5 for a bit, but having said that we do make one off’s as well so if someone wanted one in 29 we could bring that design to life. We also have a design for a more XC HexLite with 120mm of travel, using the same linkage, but again budgets will limit this for a year at least.
What are your builds/prices going to be?
We do custom builds and will make a bike to any specification, and we have a good hook up with X-Fusion, as they helped us dial in the rear suspension based on our platform, so we’ll offer an X-Fusion build as standard for rear shocks. On top of this, the Sweep fork is an awesome piece of kit for the price. As for pricing working in titanium the raw material make the frames expensive to make, but we try and keep our prices as grounded as possible so for a full build with: X-Fusion/XO/X9/Wolf Tooth/Hope Pro 2/Flow you’re looking at about £4500.
What type of rider do you wish to appeal to?
That is actually quite tricky as without wishing to offend, most people who are into Titanium mountain bikes tend to ride; fully rigid, single speed, have beards and SPD sandals. Our bikes have mostly been a bit of a Ti anomaly, as they’re for more aggressive trail riding, the Hex is the natural progression of this and therefore has a broader, possibly younger market and we’re hoping that it will appeal to the kind of rider that wants an all mountain bike that’s unique, tough and will last longer than a few seasons.
Will you be adding any graphics of any kind or keeping it subtle?
This is my nemesis. My background is as a graphic designer, so the thousands of hours I’ve spent designing graphics for our bikes only to bin them is the stuff of legend. Because of this, I like subtlety and we have a really nice head badge now that’s taken 6 years to design, so I’m happy to stop there.
Words Jim Buchanan | Photos Doc Ward, Robin Schmitt
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