Started by former South African professional road cyclist, Mark Blewitt, the SwiftCarbon brand is making great strides on the road internationally. But how would its first dual suspension bike match up to the high standards expected by South African marathon and stage racers? We first spotted the SwiftCarbon Evil Twin dual sus frame at the 2014 Africa Cycle Fair, where it created a bit of a fuss. We finally got to ride one during a typically dry and dusty Highveld winter.
The TREAD test team
Photos: Dino Lloyd
The electric blue colour is ridiculously distinctive! It’s the first thing you notice and no matter who we asked, everyone either liked it or loved it. It does also come in black with blue trim for those that prefer stealth mode…
The goal with the Evil Twin was to create the most efficient race bike for cross-country and marathon racing. So light weight and stiffness were critical elements. SwiftCarbon went with a combination of T700 and T800 high modular filaments from Toray in Japan for the frame material. For SwiftCarbon, carbon quality is a priority, so its material choice as well as manufacturing methods are among the highest you will find in bicycles.
For suspension design, Swift Carbon got South African suspension design guru, Patrick Morewood to consult, the result being a relatively simple single-pivot system that’s exceptionally neat, tucking the rear shock tight at the inner junction of the toptube and seattube. This allows for the carrying of two bottles inside the frame, also a key priority for SwiftCarbon, understanding the importance placed on this by serious marathon and stage racers.
The frame looks very low and sleek. At 91.3mm, the headtube is height is low, minimising the need for an overly dropped stem. The toptube is curved on the seattube end, while the downtube is large at the headtube and even larger at the bottom bracket.
The rear triangle sees asymmetric design of the bottom bracket, seattube and chainstays for optimal stiffness and the accommodation of a front derailleur – for those that will run one. There’s no bridge on the seatstays, which offers generous tyre clearance – no doubt good for mud riding (we never got to test it in truly muddy conditions).
There’s provision made for a dropper seatpost cable and a carbon cover that extends virtually the entire length of the underbelly of the downtube to protect the frame from impacts and act as a cable guide.
The workmanship and finishing on the frame is exceptional and shouts quality and attention to detail.
Our test rig came with a RockShox Monarch XX shock with 90mm of travel and remote lockout. The fork was a RockShox RS1 with 100mm of travel and remote lockout.
The wheelset was SRAM’s Roam 60 carbon hoops with Schwalbe Racing Ralph Snakeskin tyres. The drivetrain was all SRAM XX1 1×11 and the brakeset SRAM’s Avid Guide RSC. The cockpit comprised Ritchey WCS bars, seatpost and stem. A Shimano XT 2×11 option will be available in 2016. It comes in four sizes – XS, S, M, L
To be honest, when we first saw the Evil Twin we grabbed our lower backs. The super-low looking set-up made us wince a little. Even our most agile tester… But that apprehension was soon brushed aside once we began to ride it. It must be an optical illusion because we never felt any real difference in posture to our regular dual-sus marathon bike set-up. With a 71.5-degree headtube and 74-degree seattube, the Evil Twin is on the aggressive geometry side.
Not that this is too relevant, but a bike with such an aggressive looking pose is usually a bit harder to wheelie. However, our testers felt the Evil Twin was one of the easiest-wheelieing bikes they’ve ever ridden…
Anyway, back to the important stuff. How does it climb? Exceptionally well. You’re very aware of the very direct power transfer on the Evil Twin, something we haven’t experienced to this extent other than on the Bianchi Methanol and the BMC Fourstroke 01. It’s just so stiff and responsive. We actually thought the fact that there is no bridge on the stays might affect the stiffness and acceleration, but it doesn’t; not that we felt anyway.
At just under 11kg (without pedals), the Evil Twin isn’t super light, but it’s certainly not heavy. We feel there’s almost a perfect balance between stiffness and weight. Often, favouring one too much can lead to sacrificing the other to some degree.
Descending was good, but we did feel the rear shock lacked the responsiveness we’ve come to expect from high-end dual sus marathon bikes. Small bump compliance was good, but bigger hits felt too much like, well, much bigger hits… Apparently the new Fox Float shock will be a spec option going forward, which may improve this. It’s not a major thing if you’re a race snake, but all our testers noticed it. The RS1 fork seemed to handle descents, even the most gnarly, with great poise.
Speaking of the RS1 fork, we reckon it played a part in making the Evil Twin a wicked handler in turns. There’s a stability and stiffness on the RS1 that you just don’t feel on ‘normally orientated’ short-travel forks. The Evil Twin carved through turns (both tight and wide turns) with predictability and superb control, even though we found the bars a bit narrow.
The SRAM shifting was crisp and faultless. Our testers felt the gearing was adequate for most climbs, even steep, technical critters, but less conditioned riders will do best to go with a 2×11 (the frame is Shimano Di2 compatible by the way)
We found the SRAM Roam 60 wheelset to be impressive – firm in turns and over the rough with no hint of weakness, even with unexpected forces through awkward, tight or technical turns. We used two large water bottles without any forced or missed removals and returns. This is a little unusual on dual sus bikes.
With the convex curve of the toptube, standover height is a little tight. Our test bike was a Small (which is similar to a Medium on most other brands). For smaller riders, there’s an Extra Small size, which comes in a 27.5 (650b) wheelsize, ideal for smaller women.
If you’re going to be spending a hundred thousand rand on a bike, you expect premium quality and a high-performance experience. Well you get just that on the Evil Twin. Aside from the rear shock, which we felt fell a bit short of our expectations, we were highly impressed with Evil Twin. It’s a high quality, thoroughbred racing machine for those serious about XC, marathon and stage racing. It’s also available in a slightly down-specced version in 2016 at a lower cost.
SIZES: XS, S (tested), M, L
TOP TUBE LENGTH: 580mm
SEAT TUBE LENGTH: 419mm
HEAD TUBE ANGLE: 71.5 degrees
SEAT TUBE ANGLE: 74 degrees
CHAINSTAY LENGTH: 444mm
PRICE: Full bike as tested R99 200
Frameset Monarch XX shock – R37 380.00
Frameset Monarch XX shock/RS 1 fork – R51 720.00
Frameset Monarch XX shock/SID XX WC fork – R48 890.00
FRAME: Toray 700/800 High Modular Carbon
WEIGHT: 11.18Kg (with pedals)
FORK: RockShox RS1 with 100m travel and remote lockout
SHOCK: Rock Shox Monarch XX with 90mm travel and remote lockout
SHIFTERS: XX 1
FRONT DERAILLER: None
REAR DERAILLER: XX1
CRANKSET: XX1 34-tooth
BRAKESET: Avid Guide RSC hydraulic disc with 160mm rotors
WHEELS: SRAM Roam 60
TYRES: Schwalbe Racing Ralph Snakeskin
OTHERS: Ritchey WCS Carbon seatpost and handlebars (680mm), Ritchey Super Logic stem, Fizik Thar Saddle
CONTACT: www.swiftcarbon.com; 021 426 6000
SWIFTCARBON SAYS; ALL CARBON FIBRE IS NOT CREATED EQUAL
Just as there are different alloys of aluminium and steel, so there are numerous types of carbon fibre. So many, in fact, that saying that a frame is made of “carbon fibre” really doesn’t reveal very much. No one can ever tell exactly what kind of carbon a frame is made of just by looking at it, regardless of the finish on the surface.
SwiftCarbon bikes use a combination of T700, T800 and T1000 filaments, originating from Toray in Japan, the world’s largest producer of carbon fibre – much of which is used by the aeronautical and defence industries. We also use filaments from Mitsubishi Rayon, and the combination of Toray and Mitsubishi carbon fibre help us to deliver the superior ride quality that SwiftCarbon bike.
EPS MOULDING SYSTEM – BECAUSE CONSISTENCY MATTERS
Making a carbon fibre frame involves compressing layers of carbon weave and epoxy resin into a mould to get the desired shape. Traditionally, inflatable bladders are used inside the frame to force the material into the mould, but because the shape of a bladder can’t be finely controlled there can sometimes be wrinkles or inconsistent thickness in the finished frame. To avoid this, we use expanded polystyrene – essentially the same stuff that helmets are made from.
We can make EPS formers to the exact shape that we want before laminating carbon fibre around them and placing the whole lot in a mould. When heated, the individual beads in the EPS formers swell. Out in the open they’d reach 40 times their original size, but constrained by the mould they exert pressure on the inside of the carbon fibre, pushing it into exactly the desired shape with consistent thickness and no wrinkles. The result is a lighter, stiffer and more consistent final product.
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*Originally published in TREAD Issue 36, 2015 – All rights reserved