Three categories, one bike, zero boredom: The Scott Scale RC Aero concept is typical Dangerholm - technically precise, visually radical, in terms of content somewhere between madness and genius.
The unique bike rolls on 2.25-inch MTB tyres, which sit on 45-millimetre-wide prototype rims with a 70-millimetre deep wave profile. Aero meets arable. The WERT StW-M titanium crankset weighs a feather-light 314 grams, the Berk Lupina monocoque saddle just 99 grams; shifting is handled by a Sram RED XPLR drivetrain with 13 gears and a 10-46-tooth cassette, braking with 612-Parts calipers and carbon Ti X-Rotor aero discs.
The mission: to combine the efficiency of a road bike with the off-road fun of a mountain bike - without compromise. Or at least with very entertaining ones.
The basis is the frame of the Scale Gravel, combined with the seat tube section of a Foil RC road bike. Added to this are aero components that look more like a wind tunnel than a forest track. The result is a gravel bike with road bike hips and MTB shoes.
The frame of the Dangerholm Scott Scale RC Aero
The geometry is exciting: a Scale Gravel frame in size Medium is used - actually too small for a 183 centimetre tall rider. But that is precisely part of the concept. The shorter reach ensures a compact front end, which is offset by the longer grip position on the drop bar. Sounds paradoxical, but apparently it rides exactly as it is intended: fast. In short: If gravel, aero and MTB were allowed to discuss on a workbench - this would probably be the result.
Foil seat tube (road bike) meets scale frame (off-road)
The seat tube section comes from an accident-damaged Scott Foil RC - high-end recycling. Dangerholm removed the upper seat tube from the Scott Scale Gravel and transplanted the Foil component in its place. A carbon specialist then joined the two parts with several layers of carbon fibre - custom work instead of a DIY solution.
The integrated seat clamp of the foil element in a striking P-shape is a characteristic feature. At the front, an additional carbon tube complements the design and creates a wedge-shaped aero contour - visually road bike, functionally gravel.
No stone was left unturned in the drivetrain area either: The chainstay on the drive side has been massively modified to make room for chainrings with up to 46 teeth. In its standard state, the Scale Gravel limits the size of the chainrings - after all, the geometry is not designed for high-speed setups.
After the structural work, the test of patience began until the surface was perfectly smooth and suitable as a base for painting. The Scott fork, on the other hand, remained largely in its standard condition. Only the three rivets on each side for attaching the panniers had to go. Aero just doesn't know panniers.
Darimo Nexum Drag Gravel Cockpit
In the cockpit area, Dangerholm relies on the Darimo Nexum Drag Gravel Cockpit in 80 x 380 millimetres with a full -12 degree stem angle. The compact unit was specially developed for two MTB gravel projects - nothing off the shelf, everything with a plan. Due to the comparatively long reach of the frame, the stem is significantly shorter than on classic gravel bikes. At the same time, the slacker steering angle calls for a more radical solution: a standard -6-degree aero stem would make the handlebars look like a wing ready for take-off. Not exactly streamlined.
The -12 degree stem, on the other hand, neatly positions the aero shape and ensures a flat, harmonious line. The headset wedge, cover and spacer are customised - for seamless integration and fully internal cable routing. It could hardly be tidier.
For the handlebar tape, Dangerholm uses three millimetre thick Syncros RC Bar Tape. This is rather unusual for a gravel bike, as the 4-millimetre gravel version would normally be used. However, the generous tyre volume does the damping work here.
The Sram RED E1 brake levers can do more than just stop: With the integrated bonus buttons, you can control the Hammerhead Karoo directly from the handlebars - technology meets comfort. The usual flat-mount brake callipers do not fit on the post-mount frame. Instead of 180-millimetre discs with adapters, Swiss high-end comes into play: 2-piston brake callipers from 612 Parts, manufactured in Germany, ensure clean deceleration.
Sram RED XPLR with Ceramic Speed OSPW
The drivetrain is based on the Sram RED XPLR rear derailleur with 13-speed 10-46T cassette and SRAM RED chain. The Alpha derailleur pulleys are easy to clean and have a dust protection system for the bearings. The WERT Cycling StW-M titanium crank is almost completely drilled through, making it virtually hollow. The weight is 314 g. The pre-production version has a slightly wider axle than normal. This allows a 6.5 mm offset SRAM RED Aero Power Meter chainring with 44T, while MTB frames normally require 3 mm offset. The Q-factor remains narrow and aerodynamic. The CeramicSpeed BB ALPHA bottom bracket uses improved seals for longer durability with low frictional resistance. The pedals are Xpedo M-Force 8 Ti.
Prototype rims with 45 mm inner width
The prototype aero wheels are based on the look of the Zipp 303 XPLR SW, but are extra wide and come in a version that can also take 2.25-inch MTB tyres. With an inner width of 45 mm and an outer width of 52 mm as well as a 70 mm deep wave profile, they offer the perfect basis for voluminous tyres. The wide rim profile ensures that the tyres remain stable at low pressures. Normally, tyres can "fold" over the rim when braking hard, cornering or sprinting - this does not happen here. The wide rim base increases predictability, comfort and speed on rough surfaces without making the bike faster on smooth gravel than a normal gravel bike with 45 mm tyres.
Initially, there was concern that tyres that were not specially developed for this width would be too square and the shoulder lugs would be poor for cornering grip. However, practice has shown that extreme lean angles on gravel are extremely rare. On the road, the tread pattern allows the tyres to lean heavily, but on gravel you slip away much earlier anyway - so a round tread pattern is not even necessary here.
Maxxis Aspen on Extralite HyperSmart 3
The rims are fitted with Maxxis Aspen ST MaxxSpeed Team Spec tyres in 2.25 inch width. The logos have been blacked out for a clean, minimalist look and feel. Although the tyres are tubeless-compatible, Dangerholm mostly uses REVOLOOP REVO.ULTRA MTB TPU tubes - a touch of old school with a high-tech advantage.
Technical specifications
- Frame: Scott Scale Gravel with Foil RC seat tube section, carbon
- Fork: Scott, rigid, modified
- Seatpost: Syncros Duncan SL Aero CFT
- Saddle: Berk Lupina Monocoque, 99 g
- Handlebar/stem: Darimo Nexum Drag Gravel, 80x380 mm, -12 degrees
- Handlebar tape: Syncros RC Bar Tape, 3 mm
- Brake lever: SRAM RED E1
- Brake callipers: 612 Parts, 2-piston
- Brake discs: Carbon-Ti X-Rotor Aero
- Rear derailleur: SRAM RED XPLR with CeramicSpeed OSPW X ALPHA
- Cassette: SRAM RED XPLR, 13-speed, 10-46T
- Chain: SRAM RED
- Crank: WERT Cycling StW-M Titanium, 314 g
- Chainring: SRAM RED Aero Power Meter, 44T, 6.5 mm offset
- Bottom bracket: CeramicSpeed BB ALPHA
- Pedals: Xpedo M-Force 8 Ti
- Rims: Prototype, 45 mm inside, 52 mm outside, 70 mm profile
- Spokes: Alpina Hyperlite Aero
- Hubs: Extralite HyperSmart 3 with Boost adapter kit
- Tyres: Maxxis Aspen ST MaxxSpeed Team Spec, 2.25 inch
- Tubes: REVOLOOP REVO.ULTRA MTB TPU
- Size: Medium
- Weight: 9.00 kilos including pedals
Who is Gustav "Dangerholm" Gullholm?
Gustav Gullholm, better known as Dangerholm, is a Swedish custom bike builder who takes technology, lightweight construction and design to a new level. In recent years, he has built the lightest XC bikes in the world - and even the lightest 29" downhill bike. But Dangerholm is not just about grammes: Every bike must not only be ultra-light, but also ride great and look really good.
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Laurin Lehner
Editor
