The concept behind the tuning bike
With the Hyper Spark project, the Swedish company Tuning professional Gustav Gullholm alias "Dangerholm" He had two goals: on the one hand, he wanted to build the fastest and most efficient race fully possible, and on the other, he wanted it to be the cleanest bike ever built with internally routed cables. To achieve this, he was inspired by modern racing bikes and so-called hypercars (the most exquisite super sports cars) to give a full-suspension mountain bike the same sleek and clean look. The idea is not new, as the Magura MCi concept bike just under a year ago. Cables and cables are also being routed into the frame via special stems or headset caps on more and more production bikes. However, no one has ever implemented cable integration as consistently and radically as on the Hyper Spark.
"It was important to me to have fully internal cable routing on the handlebars, but at the same time the bike should retain all the functions of a modern bike. That's why it was out of the question to do without a dropper seatpost or a suspension lockout that could be operated from the handlebars.
The latest electronic components such as the wireless Sram AXS shifting group or the Live Valve suspension from Fox made the conversion easier for me, but there were still a lot of modifications to be made and ingenuity was required. That's why I made a special steering stop system for the Spark RC SL frame so as not to damage the internally routed cables. I also had to modify the handlebars and the suspension fork to be able to realise my cable routing in the first place. Then I had to reinforce everything to ensure safety. I invested endless hours to achieve a perfect finish. Because even though the bike is so unique and special, I really wanted to give it a 'standard' look. Although I made most of the parts in my workshop, I wanted everything to look as perfect as possible. As if it came from a large research and development department or a renowned design department.
While the pearl white colour is the trend for 2021, the Hyper Spark project is intended to give a first glimpse of what mountain bikes could look like in five or more years. Nevertheless, I didn't build the bike for any showrooms, but to ride it."
The technical highlights of the Hyper Spark in detail
Frame
For a clean look, all cable entries that are no longer used have been covered. The pearl white colour is called Oryx White and actually comes from the Volkswagen range.
Steering stop limiter
One of the biggest challenges was the steering stop to ensure that the internally routed cables were not damaged. A handmade aluminium plate with a replaceable stop pin sits directly behind the head tube on the frame. It encloses the entire steerer tube and head tube area and is wrapped in carbon. Underneath the handmade cover is the hardware that is attached to the steerer tube and prevents the handlebars from being bent too much.
Handlebars
To allow the brake lines to run inside the handlebars, holes were drilled and the areas on the outside were wrapped in carbon to reinforce them. There is another hole on the steerer tube so that the cables from the stem can enter.
Suspension fork
Holes were drilled in the rear of the steerer tube so that the rear brake hose and the Fox Live Valve cables could be routed into the frame. As it is never a good idea to drill holes in the steerer tube, the tube was heavily reinforced afterwards. At the top it has a "star nut" with a solid aluminium thread. If this is removed, the handlebars can be removed without removing the brake hoses, as these protrude slightly upwards through a recess. The cables are routed down through additional guides at the rear of the fork crown. The Live Valve front sensor, which normally sits at the rear of the fork crown, has been modified and sits on the brake calliper so that the cable runs together with the front brake hose.
Impellers
The Syncros Silverton SL are full carbon wheels. The rim, spokes and hub flanges are moulded in one piece. This means that they have continuous fibres from one end of the rim to the other instead of separate spokes. They have an inner rim width of 26 millimetres. Cushcore XC tyre inserts are also fitted to improve the ride quality and provide additional puncture protection.
Gear lever
The controls for the AXS rear derailleur and dropper post are Zirbel Twister WE01. You could say that they are a mixture of thumb and twist grip shifters. A shift ring with a trigger rotates around the handlebars, with magnets inside the springs. You have a click in each direction: to shift to a lower gear, you press down with your thumb, to shift to a higher gear, you press up. You can also hold them down to shift several gears. The cables of the Zirbel Twister are normally connected to a Sram AXS BlipBox. On the Hyper Spark, however, they are soldered to the circuit boards of the AXS triggers. The cables run under the grips and all the electronics are hidden in the handlebars.
Brakes
The extremely light yet strong Trickstuff Piccola carbon brakes have special hollow couplings that change the exit angle of the brake line and have been specially developed for internal routing in the handlebars.
Drive
The drivetrain has a fairly massive 40 tooth chainring and a 10-50 tooth cassette. It comes from Garbaruk and the chainring has been specially manufactured for the Hyper Spark. The rear derailleur has a CeramicSpeed OSPW system for reduced friction and a CeramicSpeed UFO chain for racing use. The special coating is suitable for dry weather and should last up to 600 kilometres. All bearings (wheels, bottom bracket and headset) are also from CeramicSpeed.
Seat posts
For everyday use, there's the Rockshox Reverb AXS with 170 millimetre drop and Syncros Belcarra R SL saddle. The cool thing about the latter is that the carbon rails and the shell are manufactured in a single step. Using special moulds and a special process, the carbon fibres are dried, shaped and then cured in one piece. In addition, there are two lighter, slimmer seat post units for easier terrain. Both are manufactured by Berk in Slovenia. On the white model, the seat post comes from Schmolke Carbon and the unit has a special rail construction that allows the seat shell to flex more. The black Berk seat post combination is even lighter and stiffer, but also offers less comfort.
