Building The Ultimate Adventure Bike

A rare case of OCSB has led Mezza on a mission to build the ultimate adventure bike, basing his creation around the engine of the BMW K75GS, he tells ABR about his custom build.

The Road of Excess leads to the Palace of Wisdom…You never know what is enough until you know what is more than enough.” – Famous quote by William Blake within the writings of ‘­ e Marriage of Heaven and Hell’ circa 1790.

Quite an apt title when you consider what overland travellers have to contend with when riding down the many roads on an adventure. Some keywords in that quote; ‘excess’ and ‘wisdom’.

I’ve had my head in a shed all my biking life. Throw into the fold that I suffer a rare condition known as OCSB (Obsessive Compulsive Special Building) and it starts to get ‘excessive’ and much ‘wisdom’ is needed to know which ‘road’ to take to avoid being summoned to the ‘Palace’ (the Missus calling from home whilst clutching the latest joint bank statement)!

When it comes to what constitutes as the ideal adventure bike there’s plenty of room for debate; do you go lightweight and medium power? Do you go for a house on wheels with everything you’ll never need onboard?

I currently own bikes fitting each description but have decided to seek out a guru of fabrication to create what I believe to be ‘The Ultimate Adventure Bike’!

I have decided to build my bike around the engine of the BMW K75GSA.

‘Why on earth would anyone build an adventure bike around a great heavy lump of the K75?’ It’s very simple really, the whole concept of this build is to go travelling with the ‘Ballast Unit’ (the missus, and I’m dead when she reads this) and have the time of our lives with as little hassle and troubles as possible, on a machine with a ‘bomb proof’ engine that I’ve built myself.

To me, it’s a fantastic way of capping off your biking life.

Front Right
Front Right

A few years earlier I’d seen an image of a K75GS that some guy had built and I fell in love with its oddness and ugliness. In 2011 a complete eBay ‘Ratter’ donor bike was duly purchased, the ‘bid now’ button was pressed while travelling in India after consuming copious amounts of whisky with my buddy Mark.

That was it, committed and challenged. The bike stood for a couple of years gathering dust in a massive Cornish barn. A work-oriented relocation to the ‘Great North East’ saw garage space acquired and the next step was finding someone who could work magic with steel tubes. This search led me to a rather special place,

the Westgate Road area of Newcastle (what you can’t get done or achieved with motorcycles on the ‘Hill’ could be written on the back of a postage stamp). All enquiries led to a gentleman called Colin who runs a motorcycle engineering company, Axis Motorsport. Little did I know I was about to meet a fellow ‘no compromise’ ex-moto crosser who also had OCSB! Palms were spat on and hands were shook, it was game on!

Bike Concept

To me, an RTW adventure bike should be your home on two wheels. ABRs love to Farkle but too much can be a recipe for disaster so basic requirements and necessities should be addressed first.

Two-Up/Pillion Riding

This affects all areas of the bike. Having covered over 50,000 miles on a GS1200 Adventure (mostly solo) I came to a simple conclusion; GS1200 seats, bars and control gear.

Suspension has been sorted by the tried and trusted route of Mr Alf Hagon at the rear and front forks by a well-known MX suspension specialist from up-north, Gav from G-Force Suspension. He has taken the original springs out of the KTM 50mm ‘extreme’ stanchions and had custom springs wound to his formula according to the weight distributions I gave him.

Front Forks
Front Forks


The frame has had a good seeing to with the hacksaw there’s no doubt there. Headstock has been increased and braced to accept the Aprilia Caponord 50mm yolks. The whole back end is bespoke ‘Axis’ craftsmanship by Colin to accept the GS1200 seats and the luggage system. Front rails have been added to cover many roles including footrests, sump/engine guard, crash bobbin mounts and the fuel cooler mounting.

Final finish will be a phosphorous dip and powder coating in very controversial colours! The front beak of the bike will hold a lightweight roll containing a double sleeping bag and Exped mattress with a hinged affair of typical Axis orientation.


Left standard bar some brand new components such as upgraded 50AMP alternator, starter motor, water/oil pump, hoses, thermostat, oil pressure and water temp switches, many of the obvious seals and ‘O’ rings too. K&N air filter for ease of maintenance and simplicity.

Tank Range

OK, this is where the ‘excess’ element kicks in; I hate having to constantly stop for fuel. As an ex-street fighter builder and an avid ‘Paris Dakar’ follower it left me in no doubt that a custom tank had to be made, of course it had to be big and ‘in your face’ ugly to match the engine!

We have measured capacity and it’s a slightly disappointing 32-litres. This was clearly not enough for what I had in mind. Much consideration and thought has lead us to the idea of an extra fuel pod that would integrate with the luggage, ‘L’ shaped to sit the pannier on. Two of these either side of the bike, one for petrol and a stainless steel one for water (more on this later).

The original K75 tank has a built-in fuel pump so a complete new ‘out of tank’ fuel system had to be designed to give the same pressure (35psi) at the rail.

Big, in-your-face tank

A classic example of how projects evolve was when a good friend of Colin’s pointed out a much-overlooked problem that occurs to fuel when travelling in hotter climates and that was the buildup of water condensation in the fuel. Being heavier than petrol it naturally seeks a lower place to rest (the reserve fuel pod). Couple this with the classic ‘K’ series puff of smoke on startup issue, we are changing the side stand to the right-hand side.

This will lend itself to persuading any water residue to take up residence exactly where we can decant it away via a well-placed tap which in turn is what I can use for the petrol stove topping up task! There will be a two-stage breather mounted high on the screen that will cater for both tanks.

Tyres And Wheels

I’m a firm believer of TKC80s. This bike is going to be a heavy old lump there’s no doubt about it and it will also be going off-road. The standard wheels went straight in the skip and the new rear is a modified GS1150 wheel.

The hub has been machined down by 10mm for centralisation and electroless nickel plated, 4mm H/D stainless spokes and the rim powder coated satin black. The rear calliper mounting bracket has been designed by Axis and CNC machined out of billet stainless steel at great expense but I have to say it has given the rear end a very factory looking finish indeed.

The rear wheel and Hagon Shocks

The front-wheel was the real headache, aesthetics had taken a grip by this stage and I knew the look I wanted to achieve wasn’t possible keeping it 21” with the tyres available. I wanted a 3” rim upfront to get that ‘Triumph Bonnie Scrambler’ look, wasn’t happening so I compromised with a 2.5” x 19” rim.

Enter another guru of his trade, Doug Richardson at Devon Wheel Building. He has built both wheels and supplied the TKC80 tyres. The front rim wasn’t tubeless but he has converted it using some complex technique. Let’s face it, wheel building is basically witchcraft!

Front Wheel
Front Wheel


The Cost Of Building Your Own Adventure Bike

It’s difficult to get an idea of exactly how much it has cost me so far because of the amount of farkling I’ve been doing!

Counting all the Goodridge hose fittings, adaptors, filler cap, breather, tank ballast foam, clips, spanners, fuel regulator, fuel filters, Walbro pump, cooler radiator, dry break connectors my Demon Tweaks bill came to £420 with my Merlin Motorsports bill at a more painful £1,500 – quite scary when you consider the VAT and postage as well!

All OE BMW bits (except the starter motor – £180 from the states, and the 50amp alternator – €250 from Germany) were sourced from Pidcocks BMW in Longeaton, my bill coming to roughly £700.

The Pivot Pegz were £165 from Adventure Spec, rear brake disc was £77, the GS1200 adventure brake/clutch lever £240 and the GS1200 handguards £40, I bought these from Motorworks BMW.

Then there’s a whole array of electrical items that I purchased from eBay and beyond, amassing to over £150 and still rising!

In total, so far, I’ve spent about £3,600, not including the base K75GSA, and the bike’s far from finished.

‘Soft’ or ‘hard’? Why not try both! Bespoke handcrafted aluminium panniers and rear storage pod. The exhaust sits snugly under the seat so no issues with ‘His & Hers’ different capacity boxes here. Colin had his own spin on how they mount to the bike so I let him run with his idea.

Upfront there will be a rack to hold a roll (as already mentioned) and front soft panniers of some description, these will mount onto 3mm ally plates that double up on the right side as the coolant expansion bottle and on the left a place for a first aid/medicine hidey-hole.

With the wide tank and front panniers, it should offer added weather protection on the hoof. Look at Sam Manicom’s bike from the front, massive tank and ammo bags, I love that look so again aesthetics are coming into play!


I purchased an array of LED fittings from Gabe at ZEN Overland including a 6” light bar to be perched aloft the beak. Low-level amber spots as fog lights and two mega output spots, one mounted high up which will have the ability to be directed by hand with a quick-release mechanism and the other bolted to a fork brace for more directional accuracy.

Indicators and rear brake/taillights are LEDs sourced from EVS. With all of the gadgets being added, we’ve had to create space to mount it all. The ‘Electric Box’ has stolen some capacity from the extra fuel pod but solved the problem we had from the space-hungry design of the Axis frame.

Electrical bits ‘n’ bobs

Farkles And Engineering

We are building a bike from scratch here so there has been a lot of head-scratching and sucking through teeth moments! The most problematic area has been the fuel system. The fuel pump has to be mounted with gravity in mind, fuel from the extra pod mounted beneath the pannier meant that it had to go under the bike above the centre stand (a very vulnerable spot), Colin made a pod housing the pump and pre-filter in one and it’s very neat. Tank removal roadside has been taken care of by installing dry break connectors, three in total (two feeds and a tank return).

Fuel Pump PodWe are running a fuel cooler directly beneath the radiator to safeguard against overheating in the hotter climates, some might see this as OTT but it can be an overlooked issue.

The air intake will be a sealed system which climbs through the tank via a tube and will connect through a flexi pipe to some very trick gadget designed to scoop air head-on as well as from behind the screen when it’s lashing down.

The swingarm/driveshaft has been extended, 50mm added using a CNC black hard anodized spacer, titanium studs and the shaft itself has been cut, extended with a second hand 20 spline shaft chopped to length and welded by Axis. Magura hydraulic clutch conversion (by Venhill Racing) to facilitate the GS levers and also the cable ports left intact for fail-safe aspect (a clutch cable will be taped in position and swapped roadside if need be).

‘One off’ exhaust system using a Ducati 916 silencer. Huge capacity Odyssey battery. Gallons of Goodridge hosing and fittings plus two very finely crafted filler caps by Newton Equipment, also Pivot Pegz from Adventure Spec.

Magura hydraulic clutch setup

The build is nowhere near finished as yet so there will no doubt be loads of farkling and bespoke carried out to persuade the finished creation. Going down the road of excess yet again for me has blown my original budget well and truly out the window but this is the price you pay for bespoke motorcycle nonsense!