Skrunkwerks R90 Scrambler
From speed to utility, salt to road, this build is a bookend to the Skrunkwerks salt racer. From the outset, focus was on practicality, comfort and performance. In short, a long-legged mile muncher that wont loose its lolli when the bitumen runs out. Plus some more ooomph than the stock R90. The large slab sided tank of the R90/6 spells Teutonic classic and is a solid model to form the basis of a build. But it can stand improvement in a number of area’s, these became the heart of the build’s mission.
- Bike:1974 R90/6
- The very ordinary stock ATE brakes and disk are replaced with a 4 pot Brembo (from a GSXR 750) and 330mm ECB rotor (for a Ducati 1198). Adaptors and spacers to accommodate this upgrade were supplied by R90X Big Brakes
- Renthal FatBars with compact Ducati switchblock. All wiring hidden in bars. Daytona Speedo. After market headlight bucket. All wiring replaced with aid of Motogadget m-unit. Kellermann LED bar end indicators.
- Stock tank with custom paint and kneepads of Tasmanian Tiger Myrtle by a maker of fine stringed instruments, Tim of http://timkillcustom.com/
- Engine: Completely rebuilt from bare case including increase to 1000cc. Heads machined by Skrunkwerks to suit 1000c Siebenrock ‘re-power kit’ to avoid the stepped pistons of their ‘power kit’ for the R90. Head machining included a further compression ratio increase to 10:1. More info here.
- Fitted with a Skrunkwerks dual pattern performance cam. More info here. Intake valve diameter increased to 44mm. Ported using in-house flowbench. 38mm Dellorto PHM carbs with velocity stacks for correct tuned length hidden under large K&N pod filters. Mufflers are DanMoto items (NLA I believe).
- Stock airbox replaced with a Skrunkwerks carbon fibre rear engine cover.
- Tractor sized stock flywheel replaced with the much lighter ‘clutch carrier’ of later models which also allowed the fitment of the much improved gearbox from a 1987 R100. Shifts are far less clunky.
- Custom seat and subframe with luggage rack and brackets for Legend Gear saddle bags by SW Motech Germany. Of the many modifications, the sub-frame/rack took the longest. Cutouts were milled manually..
- Kellermann all-in-one LED rear lights and bar end indicators.
- Ikon rear shocks (15mm more height at rear).
- Powder coated wheel rims with SS spokes and shod with Heidenau K60′
It’s a fun ride.
Also see Pipeburn post here: https://www.pipeburn.com/the-whole-werks-bmw-r90-scrambler-by-skrunkwerks/