For about six months, I've had an idea in mind. I wanted an HP2 Enduro - but as everyone who's tried to buy one second-hand without extensive contacts has learned the hard way, they are made of pure Unobtainium, and cost stupid money. With that on the table, I thought: Why not build my own? I know these bikes backwards, and their construction is reasonably straightforward. My first step was to look on the internet for ideas. Within five minutes, I'd discovered that that idea wasn't original, either. Airhead and Oilhead-engined specials abound! Which is a good thing, because what I saw made me REALLY want to go ahead. Jump to February of this year. The first engine-donor possibilities that came up were a low-mileage 2011 R1200R, and a low-mileage 2008 R1200S. Both would have been unquestionably good for the role, but both were also around the ZAR 60K to 65K mark. For me, that was too rich. I set an alert on a local classifieds site for BMWs in a lower price range. Two months later, a jewel popped up: a crashed, uninsured 2011 GS Adventure. I managed to pick it up for ZAR 27 500. (For contrast, if you're selling one of these in good nick here in South Africa, you can easily get ZAR 100 000 to 105 000). A couple of weeks later, I started looking for Japanese or Austrian dirt bikes to use as suspension donors. I wanted a rolling chassis or non-runner, minimum of 250cc. I quickly got bogged down in year models and technicalities. Steel or aluminium frame? What spec suspension? Which parts could I use for the project, and which could I re-sell? Learning more and more, it seemed Kawasaki KXs and KDXs were the most common, with Yamaha YZs and WRs second. I eventually got lucky: I picked up a 2006 WR250F that had thrown a rod: ZAR 5000. I've devoted a lot of thought to the frame configuration. I originally wanted the suspension donor to be a Honda CR or CRF so I could use the aluminium frame. But on balance, I moved away from the idea of building a frame more-or-less from scratch. I also stumbled across 'Motorcycle Handling and Chassis Design', by a British author named Tony Foale. Some excellent info in there - just what I needed. Due to COVID-19 and lack of space, I haven't been able to do any wrenching, but I have formulated the bare bones of a plan: - The project's frame will use the modified front half of the standard GSA rear main frame, pieces of the GSA front sub-frame, the WR's headstock, and the WR's aluminium rear subframe. The subframe doesn't have to be stupid-strong - this bike will be single-seat, and light on the luggage. - To get the front suspension geometry right, I'll be using the GSA engine as a jig, in combination with careful measurement. I want a slightly more aggressive head angle than the HP2 Enduro. - I'll be using two different sets of wheels: the GSA's standard 17" rear and 19" front for offroad, and 3.5x17 / 6x17 alloys from a K1200S for Sunday-morning mountain passes. - Bodywork will mostly be WR250, with better wind protection and a taller screen. - Lighting will be aftermarket LED, with auxiliary fronts powered through a Hex ezCAN. - Minimalist exhaust and Power Commander for a bit of extra grunt. With an anticipated 120 BHP and a target mass of 165 Kg, it should have a power-to-mass figure to rival an S1000XR - and make ShiftCam-engined GSs look silly. Now the work of actual frame design must start.