We were catching our breath after the short climb from Warner Lake up to the top of Hazzard County. Burro Pass was a riot–we yipped and hollered the entire way down. After a quick sip of our drinks and admiring the view, we got back on the pedals and began the broad, fast winding trail down the open scrub of this famous section of The Whole Enchilada. Popping and jibbing, sliding, and tucking, we were fully in ‘the flow’…until…THWACK! I slowed down and found a spot to pull off and investigate the source of the racket. My wheels were true, the tires firm, fork and shock yet sprung, when the problem revealed itself: I had impacted a loose chunk of sandstone that penetrated the downtube on my carbon frame…
A year ago, I penned an introduction to Myth Cycles of Durango, CO. Eric, the founder, and sole employee, had spent his years fine-tuning hardtail mountain and touring frames before setting his gaze upon the rare but ever-intriguing steel full suspension bike. He coined it the Zodiac and after a short while in his workshop, we were out riding frame #1 in the San Juan mountains above town. Now, with some proper saddle time under my belt on familiar trails, I feel it’s time to revisit the Zodiac and see what’s what.
First, a quick side note about my preferences as to clear the air before diving into the details. At 6’ and 175lbs, I ride almost exclusively size ‘Large’ frames and tend to prefer a slightly higher stack height than most manufacturers seem to offer. Second, I am not a terribly smooth operator: I tend to ‘play’ on the trail, much to the frustration of any friends riding behind me, and while I enjoy a plush ride, there’s definitely a preference for more pop than plow. Lastly, I do enjoy climbs, and while I am not an excellent technical climber, I enjoy a good challenge and take climbing prowess into serious consideration when considering frames.
Now with all that said, I have broken a total of three carbon frames in the past five years, which brings us right back to steel and why maybe the future is in the past.
Frame & Material
Steel full-suspension frames have recently come back into vogue; John has talked about his Starling Murmur extensively and oftentimes like a prophet coming down from the mountain. Other mountain bike media has tiptoed around the topic here and there with some surprising veneration and praise. So what’s the big deal?
The Zodiac is made from 853 butted tubes with a 44mm straight headtube, braced seat tube, an off-the-shelf shock yoke, and a cleverly bridged rear triangle. Like other small-batch builders, many finishing components are from Paragon Machine Works, thus providing easy-to-understand compatibility, measurements, and replacement parts if necessary. There is a second set of shock mount eyelets that provide a slightly slacker (measured -0.4°) stance–and for the sake of this review, the lower position was used for the vast majority during the past year.
Myth frames are simultaneously utilitarian as well as beautiful. There are no surprises: the cable routing is external except the dropper post that joins its tethered compatriots along the downtube back towards the cockpit. Both the brake hose and shift housing have an obvious route that connects to brazed-on guides along the chainstays and provides enough slack to prevent issues under suspension compression. The brake mounts are simple and effective. The hardware is accessible and uses easy-to-find bearings and hardware–what a novel concept! Under the top tube and downtube are many bottle mounts, to which I mounted a Fidlock bottle.
Eric taught himself how to powder coat, therefore you have nearly full control over colors and options if you’d like. As for myself, I requested a simple white as it’s a color (or lack thereof) you do not frequently see on mountain bikes.
Geometry & Resisting Long, Low, Slack
It is beginning to feel like the edges of modern geometry are being discovered. Does the average rider need a 78° seat tube angle and a 63.5° head tube? Or how about 500mm reach for a size medium? We are fortunate that builders have pushed the boundaries and experimented, but perhaps we’re beginning to push back a little on those ideas and discovering the realistic edges of design. The Zodiac, compared to many of its contemporaries, is rather conservative in this department.
The 65° HTA is a sweet spot for a 150mm fork as it avoids the wandering-wheel problem slacker bikes tend to exhibit on climbs and in slow technical sections. With a 44mm offset on the Cane Creek Helm, there was never a feeling of vagueness or flop. The 76° STA is also not revolutionary–rather, it just works. For pedaling, your position in relation to the crankset and front center feels very balanced on nearly all terrain.
The sloping top tube is good at feeling roomy but not empty. What I mean is that with the dropper post extended, there is a good gap between the rider and their sensitivities that provides ample room to maneuver. With the dropper down, the bike suddenly feels spacious and nimble, never interfering with whatever poor line choice the pilot may steer into. You’re probably beginning to see a pattern; it’s all about balance.
Where the Zodiac deviates from the norm is its bottom bracket height and wheelbase length. This is not a short and low frame. In bucking the trend, the Zodiac has a longer wheelbase than average, and to combat the potential challenges that creates with pedal strikes and break-over angles, Eric raised the bottom bracket just enough to combat these situations. So does it work?
So we have on our hands a steel, 140mm rear travel, coil-sprung full suspension bike. Might as well just walk, right? Despite these perceived hindrances, the Zodiac doth climb. One of my favorite rides involves a series of bewildering switchbacks carved into the hillside, always loose and rocky and locally known as the ‘Hateful Eight’. Given the steepness and frequency of the switchbacks, this is an ideal testing ground that reveals how centered a bike is (gripping on the loose), if there is understeer/oversteer when leaning into switchbacks, and lastly, overall efficiency.
The Zodiac is very centered, needing very little body English to adjust to steep pitches or to weight the front or rear. The roomy reach and 76° STA does a good job at minimizing the need to lean heavily forward while still maintaining rear tire traction. The suspension action is rather lively, which can be beneficial when things get technical, but not great on a fire road ascent. The climb switch on the Cane Creek DB-Inline Coil really finds a sweet spot between locked out and active that complements the Zodiac well.
Traction was never an issue, and due to the steeper HTA than many other long-travel bikes, there is very little front wheel wander. Climbing over obstacles takes little effort, which I believe is due to the active suspension and the higher bottom bracket. Quick loading of the suspension and the bike will pop the front end over obstacles happily. Pedal strikes are a non-issue, which has been one of my personal frustrations with the last few longer travel bikes.
Does it feel efficient? Not particularly, if we’re being honest. Not that that should come as a surprise given a single pivot suspension design. That said, adjusting the low-speed compression on both the fork and rear shock and utilizing the climb switch makes a dramatic difference to the overall feel while climbing. If you are looking at building a Zodiac for yourself, ensure your shock choice has these two options, and you will never feel like the frame is fighting you on climbs.
Interlude: The Suspension Design
The Zodiac utilizes a single pivot suspension design that has a rising leverage rate. Moving the upper pivot behind the main pivot, ensures that as the rear wheel travels upwards it requires more force to compress the shock. Given this design, I opted to go with a coil as it can take advantage of that rising rate and provide more traction.
The off-the-top feel is very, very supple, which leads to that active and traction-filled suspension feel alluded to above. You can drop the rear wheel of the bike on your garage floor and it doesn’t bounce. When you first straddle the bike, that active feel is very apparent. As it moves through the travel, there is a pleasant settling point somewhere between 120-90mm of the travel that doesn’t feel wallowy or stiff. After adjusting the low-speed compression to resist overactive pedal feedback, it performed superbly. Again, the word ‘balance’ comes to mind.
Where the Zodiac begins to struggle is on big hits. While it has a strong rising rate, it is not progressive enough to prevent bottom outs if you happen to get in over your head. Realistically, I’d prefer a slightly lower leverage ratio to sacrifice some sensitivity in favor of firmness. I opted first to run the DB-Inline Coil with a 550lb spring and found myself occasionally bottoming out. I moved to the same weight (as it felt great pedaling) but opted for Cane Creek’s VAULT spring, which has a progressive rate. This was the perfect solution, allowing for active and well-behaved pedaling performance while providing enough bottom-out protection in case I screw up that 6’ drop. If you were to opt for an air shock, adjusting the volume spacers and compression should easily address this possibility if you seek more aggressive terrain.
Personally, I enjoy the predictable nature of single pivot bikes despite the potential lack of pedaling efficiency or pedal kickback. Given how good modern rear shocks have become, I think the ‘lesser-than’ reputation of single pivots is outdated. The Zodiac is a perfect example; the suspension is simple to maintain, has a predictable progression through its travel, and is highly tunable depending on your shock choice.
When climbing and riding along rolling terrain, the frame material and suspension design don’t really stand out. Don’t get me wrong, the bike feels great, just that if it weren’t for the skinny tubes between your legs, I’m not sure you could discern you’re riding on anything different than what other big-box manufacturers offer. That changes when you are pointed down, however.
The inherent character of the bike is calm. The ride is very quiet, bumps in the trail are muted, and it feels exceptionally stable. Where a stiffer frame might fight back and pass the roughness of the trail to the rider, the Zodiac glides and does so composed and calmly–it is really unlike anything else I have ridden. In fact, I still occasionally check my rear tire pressure at moments as I wonder if I have lost pressure given how smooth the ride is.
Let’s start first with fast, straightline performance. Down relatively non-technical trails, the Zodiac feels like a Mercedes S-Class–it’s planted and not easily distracted, picking up speed without feeling particularly fast, and the sensation of your pace is somewhat dulled due to the quietness of the ride. In some ways, you can achieve terrifying speed without realizing it. If it wasn’t so well behaved in the corners and chunk, I would have concerns about personal safety.
Once you find a corner, you become a believer. I will do my best in describing the sensation, as it is unique and not dissimilar to what John has described on his Murmur. First, despite the higher bottom bracket and long wheelbase, the Zodiac initiates turns very intuitively. It neither resists nor forces you to weigh the front hard and calmly takes orders. Again, very balanced. Where it differs from others is in how the frame loads up and springs back on entrance and departure. This is a unique sensation to steel frames that is hard to put your finger on, but I feel it is one of the more interesting and addictive feelings in mountain biking. The frame has a tendency to feel firm, like loading up a long pair of skis in a carve, and holding that feeling through the apex of the corner. Once you pass the apex and straighten your angle, the bike releases, and there’s an energy coming out of a hard corner that has to be experienced to be understood.
As mentioned before, the suspension is lively, and when the going gets tough, the suspension does its job well. There is very little pedal kickback straight-lining through a rock garden, and the suspension never packs up and always feels well behaved. Consecutive hits are absorbed and the frame feels like it can hold a line through just about anything, to the point where I wonder if there is some horizontal flex that helps create the calm feeling through the most off-camber chunk.
Jumping, drops, and unexpected moments of courage are easy and automatic. Getting back to the balanced character of the frame, time spent in the air, or preparing for a committed steep feels very natural. Only on drop-to-flat sort of moments does the suspension get a bit overwhelmed and struggle to absorb impact. The shock choice will be key depending on your riding habits.
The Bottom Line
Balanced. Calm. Fun. In some ways, it’s very easy to sum up the Zodiac. For a long travel 29er, it is a simple bike to live with. Myth Cycles addressed many of the issues I had with modern carbon mountain bikes: the Zodiac is quiet where the carbon frames are noisy and creaky, the Zodiac doesn’t flinch at impacts where carbon will surely be damaged, the Zodiac is externally routed where the others require patience and specialty tools to do the simplest of maintenance, and finally, the Zodiac is oftentimes less expensive and locally manufactured where the others are topping $3,500 frame-only and come from overseas.
There’s a lot to like with the Zodiac, and unless you frequently send gaps at Rampage, it will likely be a very easy bike to get along with. Oh, and you weight weenies worried about steel? Even with adding a coil to my part swap, the total weight gained was +8oz over my previous carbon wunderbike. That seems like a small price to pay for what you gain. If your priorities are durability, ride quality, and balance, then reach out to Eric and get in the queue–I suspect he’s got a long summer ahead of him.
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