Retrofuturist K100 from AG Design Fab…
BMW Motorrad has never been one to follow the flock, and the K series put that outside-the-box thinking on prime display. In the early 1980s, BMW needed a clean-burning liquid-cooled four-cylinder engine to compete for market share, and they didn’t want to copy Honda in developing a flat-four like the Goldwing’s.
Instead, the BMW bods used their experience in liquid-cooled overhead cam automotive engines to develop a 998cc inline-four which they laid flat in the frame, necessitating only a single 90° bevel drive to send power to the rear wheel. With the heads and crank aligned along the sides of the bike, the K100 soon earned the nickname “The Flying Brick.” Ironically enough, BMW’s outside-the-box led to one of the boxiest motorcycles engines ever.
Today, the K series, with its almost brutalist architecture, has become a popular donor for custom builds. This one comes from our new friend Anil Gonnabathula of AG Design & Fab, a dolly grip in the TV / film industry who builds tools and products for other camera operators as well as custom bikes.
“Over the years, working on bikes got me into welding, and then fabrication, sheet metal shaping, eventually machining and 3D printing, 3D CAD design, all self-taught because I was too stubborn to ask anybody else for help when I need to make a part or piece for a bike that I was working on.”
The bike you see here was a standout build at the 2025 Handbuilt Show, and we had to learn more. Despite the popularity of this platform in the custom world, we have to agree with Anil that many K100 builds seem disproportional, awkward, or simply boring.
“I’ve never been a fan of K-bikes but the customer insisted on the platform. It gave me a chance to change what I had seen in the custom culture around these bikes. In a lot of these builds, when a builder stripped the fairings and cut down the subframe, the motor and tank ended up looking so large and overpowering. Paint the motor black, and you end up with a giant negative void, and I rarely saw a builder leave you with something else to look at…”
The customer insisted on the platform, however, and Anil rose to challenge. The bike has a Cognito Moto inverted fork conversion, custom subframe, Motogadget electronics and console, and many other trick components.
The real highlight here, however, is the custom aluminum bodywork, which Anil shaped himself with an English wheel, power hammer, and other old-school metal-shaping tools.
“You sit there and stare at this thing, and make these lines and flow the bodywork in whatever way you want, it really makes the whole bike. And then you go to actually beat it out of metal, and you wheel it a certain order, or hit it with a power hammer in specific places, and you get the feedback immediately; for a creative process, it’s a lot like painting in that regard, every brushstroke or hammer-hit accumulates and builds until the thing in your head becomes a reality in front of you. Some guys like to hop up motors, and some guys focus on paint, but for me, sheet metal shaping is the coolest problem to solve.”
The tail section, intake snorkel, coils / alternator / battery covers, and fairing for the KTM headlight are all one-off pieces shaped in Anil’s shop. He 3D-printed a fuel rail cover / heat shield, tank badges, and the taillight lens, and the engine itself was rebuilt with upgraded injectors, a beefier clutch, and a custom-welded stainless exhaust system and silencer that required “multiple refills of argon.”
Few builders have the skills, patience, and tools to shape sheet-metal so beautifully, and that artistry pays off in this “Bavarian Bruiser” whose lines flow better than any K100 in recent memory. Jay Abate at @MotoJRefinish laid down the dusty gray-blue that seems to change color throughout the day, while Dane Utech (@plzbeseated) stitched up the saddle.
There’s a certain retrofuturist style to this build, drawing inspiration from past visions of a future full of streamlined, aluminum-clad machines. We wish that was norm rather than the multi-colored plastic of today’s production motorcycles. Alas, at least we have artists and craftsmen like Anil to shape such visions from raw metal for the rest of us to enjoy, and events like the Handbuilt Show to put them on display.
Below you’ll find our full uncut interview with Anil about the build, with more photos courtesy of Georges Schemagin (www.mr-photographer.com).
BMW K100 Custom: Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
I work as a dolly grip in the Film and Television industry, but I’ve had a shop to work on motorcycles since I started my career in the film industry, so they’ve been sort of parallel ventures from the start. I started off just wanting to ride and I couldn’t afford anything that ran, so I needed a place to rip bikes apart, learn how they’re supposed to work, and put them back together so I could ride.
Over the years, working on bikes got me into welding, and then fabrication, sheet metal shaping, eventually machining and 3D printing, 3D CAD design, all self-taught because I was too stubborn to ask anybody else for help when I need to make a part or piece for a bike that I was working on.
At my shop now, I use all those skills that I’ve acquired to make tools and products for other dolly grips and camera operators in the film industry so my shop’s purpose has changed quite a bit, but no matter what else I do or make there, there’s always a lift in the middle of it.
• What’s the make, model, and year of the donor bike?
1987 BMW K100RT.
• Tell us a little about the bike. Why it was built, inspiration, custom work, etc.
The owner and I started assembling parts and talking about this bike back in 2021; it’s taken almost five years to complete. Between my long hours as a dolly grip in the TV and Film industry and having a newborn, finding dedicated time for this bike was a challenge, but every time I stepped away and stepped back into it, I would approach this project with new perspectives and new skills to help me along.
I’ve never been a fan of K-bikes but the customer insisted on the platform. It gave me a chance to change what I had seen in the custom culture around these bikes. In a lot of these builds, when a builder stripped the fairings and cut down the subframe, the motor and tank ended up looking so large and overpowering. Paint the motor black, and you end up with a giant negative void, and I rarely saw a builder leave you with something else to look at; just a lots of up-swept skinny skateboard seats and exposed parts left behind the factory covers that were removed.
We set out to build one of these that felt proportional and intentional in its modifications. The GSXR front end conversion from Cognito Moto came from the owner, and I started cutting out and replacing the old stock subframe. With a new YSS rear shock, we had a roller. I brought the owner back in to find a handlebar position, seat height, and footpeg location, so this would truly be tailored for him.
The first pieces of the aluminum fabrication were covers to hide the coils, the alternator, and battery; all made to look like a stock, OEM extension of the motor. I also wanted to keep the fuel/air system mostly stock so I rebuilt the air intake snorkel out of aluminum instead of using the plastic factory piece. There’s no way around it so I chose to make it a highlight of the build.
The owner and I went back and forth with drawings and landed on some rough lines and sweeps to dictate the rest of the bodywork. The aluminum tail section needed to hold its own, visually, against the stock gas tank and giant 1000cc inline 4 motor. On top of this, the owner insisted on including a removable top pad of the seat that reveals a glove compartment.
The unconventionally shaped headlight (from a KTM Duke) needed a nose fairing to complete the body lines and to create a cockpit for the rider.
After seeing the bike at that stage, I added the side covers to continue the flow and to hide the ECU and custom radiator overflow tank.
The stainless exhaust system came next with copious amounts of pie-cuts and multiple refills of argon. The customer rejected every aftermarket muffler I offered, so I set out to build my own from scratch.
Given the size and shape of the space I needed to fill with the muffler, I went with a chamber design instead of the typical perforated pipe muffler, and I’m lucky that it sounds so
well because I didn’t get to hear the bike until two years after I finished the muffler.
I cut into the stock BMW wiring harness and integrated an M-unit Blue, LED lighting, Rebel-moto handlebar switches, and a Motoscope pro for the console. The ISR control levers and BSK Speedworks rear sets were disassembled and stripped to get re-anodized black.
I 3D-printed a fuel rail cover/heat shield, the tank badges, and the tail light lens for the custom tail light made from Supernova LEDs. The fuel injectors are upgraded, the clutch has been upgraded, the alternator and starter motors were rebuilt; the 1987 bits have all been restored in the process of rebuilding.
Even though we painted the frame, motor, and pretty much the bottom half of the bike black, we gave the viewer something else to look at. The darkness draws your eye to the custom painted
bodywork that floats on top of the black.
The painter, Jay Abate at @MotoJRefinish, and I spent almost three months going back and forth on swatches to find the right dusty blue grey. I wanted someone to not know whether it was either blue or grey and I’m happy to say that I can’t tell you which one it is; it changes quite often throughout the day.
I personally pinstriped the bodywork in a mixed bronze and gold and cerakoted some select components in a custom color to match.
The bike is a mixture of traditional, art deco, and retro-futurism. I wanted the finished bike to look old and worn-in but by someone in the future, and Dane Utech @plzbeseated knocked it out of the park with a seat that ties that nails that vibe and elevates the rest of the bike.
• Does the bike have a nickname?
We called it the Bavarian Bruiser for the Handbuilt Show and I think the customer and I
both like it.
• Can you tell us what it’s like to ride this bike?
It’s very nimble, and has great throttle response, lots of power at any moment — the rear end has squirreled away from me a couple times.
• Was there anything done during this build that you are particularly proud of?
The sheet metal shaping parts are what I’m most proud of: the tail section, intake snorkel, headlight fairing etc. You sit there and stare at this thing, and make these lines and flow the bodywork in whatever way you want, it really makes the whole bike.
And then you go to actually beat it out of metal, and you wheel it a certain order, or hit it with a power hammer in specific places, and you get the feedback immediately; for a creative process, it’s a lot like painting in that regard, every brushstroke or hammer-hit accumulates and builds until the thing in your head becomes a reality in front of you. Some guys like to hop up motors, and some guys focus on paint, but for me, sheet metal shaping is the coolest problem to solve.
Follow the Builder
IG: @agdesignfab
Facebook: AG Design Fab
Web: agdesignfab.com
Photographer: Georges Schemagin (www.mr-photographer.com)
The British say: “You cannot turn a donkey into a race horse”.
This custom builder however succeeded … halfway.
His work is exquisite, a tribute to his remarkable vision and to his design and fabrication skills.
Looking at the ‘bike from its right side, he has achieved the impossible.
Looking at it from its left side, the engine still looks much too “large and overpowering”.
He was completely right about not wanting to customise a Brick, but he must be commended for his extraordinary achievement, and cannot be faulted if only one side of the end product is beautiful.
Hail Anil and his work!
I got to see this machine up close at The Handbuilt Show and my what a stunner! It’s extremely detailed and well executed everywhere you look! I also had the pleasure of meeting Anil and he’s also a super good dude. We even helped each other load up the bikes to leave! Great guy, great bike, I’m glad he’s getting thr exposure they both deserve!
What a marvellous looking machine Anil,your client probably couldn’t wait to pay you in order to get out & pose on it!! I just wish your piece had sound on it coz I bet that exhaust note sounds the nuts.Well done Anil,lovely job.