The SMIDSY Bike Build Part 2: Smart Choices
Proudly supported by Maurice Blackburn
With the bike - a 1986 model BMW K100 LT - sourced for the SMIDSY Bike Build in June, Antique Motorcycles started disassembling the big Beemer soon after, to see what restorative work was required before the custom work could begin.
Smart Choice
With safety being the driving force behind this build, picking a BMW seemed natural, as the brand has a great reputation for advanced technologies in terms of safety and mechanical innovations. The K100’s flat inline four engine is a good example of the latter and shows the sort of clever thinking BMW was implementing, even back then. Simpler and easier to access, with a lower centre of gravity and better suited to shaft drive operation, the K100’s 987cc flat four engine (developed particularly for this model) also saw the introduction of breakerless electronic ignition and fuel injection on BMW’s two-wheel range. Replacing the Bing carbies seen on BMW’s boxer twins, the Bosch fuel injection system not only delivered more power, but improved the spread of power and was cleaner and more economical than BMW’s Boxer twins of the time. It’s components like these that played a part in making the K100 a smooth, safe and comfortable ride when it was new. This will transfer across to this café racer custom, as the factory running gear will be retained, as will the basic geometry.
The BMW’s other high-end componentry, like the Brembo brakes and Koni shocks, will be kept, too, but rebuilt or replaced as required.
Essentially, Antique Motorcycles are keeping all the “good bits” of the BMW and removing the bad, then adding some appearance modifications that’ll make the finished article stand out from the pack. As reported in Part 1, Antique’s tear down of the K100 LT revealed it to be generally solid - as you’d expect - with the only areas of concern being the wiring, fork seals, brake calipers and handlebars. None of these were surprising, though, as we are dealing with a 30-year-old bike.
Now, with the frame and engine separated, some of the more detailed custom work can begin. . .
DOCKING THE TAIL
With safety being a key component of this build, changes won’t be made for the hell of it and they certainly won’t be made if they’re not going to be safe.
So, when it came time to cut and reshape the K100 LT’s oversized rear end to suit the café racer theme of this build, Reece from Antique Motorcycles did the job properly.
“We modified the rear frame rails and lifted them up two inches,” Reece explained. “After that, we put the whole frame in a jig and checked it for straightness.”
Additional tube sections have been added to both strengthen the repositioned frame rails and provide extra support for the rear shock mounts.
To cap this off, additional sections will be added, that will also serve as a mounting point for the tail light.
GIMME A BRAKE
Not many motorcyclists need to be told of the benefits of Brembo brakes. Fitted as standard to this K100 when it was new in 1986, Brembos were top of the line then and are still the benchmark for braking performance today.
Of course, the units on this bike have suffered the ravages of use and time, so Reece says the calipers will need rebuilding and the disc rotors replacing.
“We are sending our worn out discs off to Metal Gear in Queensland - they’re a great company to deal with and recondition disc brake rotors on a change-over basis. We’ve spoken to Bruce at Metal Gear and he’s going to help us out.”
TAUT AND TIGHT
In a similar vein to the Brembo brakes, the BMW’s Koni suspension will be retained for the project as its quality is undeniable. However, to ensure they’re safe and functional, the rear shocks will be fully rebuilt, while new seals and progressive springs will be fitted up front.
When the BMW’s 987cc horizontal four is reco’d and refitted, it’ll retain the original exhaust headers, too, but the long factory silencer will be swapped for a more compact, GP-style stainless steel muffler. Reece is a big fan of those beautiful twisted headers, so was keen to keep them in place.
Rust in the handlebars wasn’t the problem it might have been if this was a stock restoration. They were going to be ditched anyway, with a set of clip-ons already trial-fitted, but like the rest of the componentry, these will be sized and placed so they don’t adversely affect safe riding.
CAFFEINE SHOT
As you can see from the photos, some of the café racer-influenced aesthetic changes that will individualise this bike are already underway.
These include the aforementioned clip-on bars and rearsets, as well as a radiator shroud from a similar era K100. As the K100 was the naked companion to the K100 LT tourer, the shroud fits the bike’s radiator and fuel tank perfectly.
Slung just aft of this on the offside is a RamFlo air filter that will lend an appropriate old-school look.
The headlight is from a new Indian Scout. As Antique Motorcycles are Indian dealers, it was convenient, but it looks good and will be functional, too. “It suits the purpose perfectly,” Reece explained, adding that the Scout’s single light beam also has good hi/lo beam characteristics.
The indicators and other legal essentials are still a work in progress, while Reece and the team have also been toying around with ideas for the ducktail, which will be revealed in a future instalment.
TYRES AND TRINKETS
Reece says the original BMW alloy wheels will be retained for the café racer, but cleaned and repainted before they’re sent off to Pablo’s Tyres in Mulgrave (VIC) for fresh rubber. The type of tyres to be used – chunky or slim, blackwall or whitewall – will be decided at a later date.
“Rick from Pablo’s is an expert at matching the right tyres to custom builds, so we will tap into his expertise for our new rubber,” Reece explained.
Many of the other accessories, including mirrors, reservoir covers, levers, indicators, grips, etc. will be sourced through MCA Motorcycle Accessories Supermarket in Dandenong (VIC) and BikeCraft in Mordialloc (VIC), close to Antique MC’s base in Cheltenham.
“Brad from Bike Craft is an expert at selecting accessories, so we will be leaning on him for advice. Being a distributor of Rizoma accessories, his choice well no doubt be a little biased, but hey, we’re talking about Rizoma here, so that’s a good thing,” Reece laughed.
Part 3: Bringing It All Together
Next article, we’ll reveal more of the SMIDSY Bike Build process and may even include a couple of pointers on how the finished build will look.
SUPPORTING SAFETY
The SMIDSY Bike Build is an initiative of Maurice Blackburn Lawyers, supported by Antique Motorcycles and JUST BIKES. The goal is to produce a custom motorcycle that combines attractive appearance touches with the sort of safety features that’ll make a great-looking custom a great and safe bike to ride, too.
Maurice Blackburn Lawyers are driving the project, with the aim of further spreading their SMIDSY – Sorry Mate I Didn’t See You – motorcycle safety message.
Antique Motorcycles will undertake the build, with support from selected specialty suppliers, while JUST BIKES will document the build process.
The finished SMIDSY Bike Build will be revealed in JUST BIKES and debut in the metal at upcoming bike events, including the Distinguished Gentleman’s Ride this September.
