When a conference Focusing very closely on one bike model, that’s usually a good thing. They know what needs fixing and what should be left alone. And where to get the loudest bang.
That is the philosophy of Lourenço’s Brazilian boutique Retrorides. Founded by brothers Gustavo and Rodrigo Lourenço and their father José, they’ve created a niche for very sharp BMW K series cafe racers — like this dark and handsome K100 RS.
Lourenços is based in a town a few hours by car from the big city of São Paulo. Their company is known throughout Brazil for its excellent products in cars and trucks, as well as BMW motorcycles.
However, it is clear where the passion lies. “I have always been obsessed with the K series,” confessed Gustavo. “The engines of these bikes fascinate me. I’ve done countless projects with them, but this time I wanted to do something different.”
Sadly, José passed away in December – but he will be delighted to see the work his sons have done on this building. Retrorides has always focused on improving the contours of a bike, and that’s exactly what happened with this project.
They took inspiration from the more basic 1980s K-series models, which were ‘naked’ roadsters, but made an important change to the trickiest part of the styling – the fuel tank.
The original tank had a distorted bottom line, designed to accommodate the radiator. It seems logical that all the OEM bodywork is in place, but as soon as you remove anything, it becomes like an isolated jigsaw puzzle.
“The ‘naked’ person K100 Gustavo has a small “radiator guard” next to the fuel tank,” says Gustavo, “so we started the project from this part. The most difficult task was to turn this work into something to be admired, in cafe racer style. ”
After hours of design and several models scrapped, Retrorides came up with a solution: a flush panel with a grill that complements the other lines of the tank.
After modeling the part in 3D, Retrorides manufactured it on their 3D printer using carbon fiber, with the grille machined from billet aluminum. It’s one of the cleanest solutions we’ve seen and instantly transforms the look and feel of the K series.
There are more stylistic workarounds to be found at the front of the slats, with a new spoiler surrounding a circular headlamp. This is another piece of design and 3D printing, combined with the iconic kidney grille of BMW cars. This grille is also machined with CNC aluminum.
The styling is again completed with a new tail unit, which sits on a truncated subframe. The pleats simulate the contours of the gas cap and there are integrated LED taillights. To keep things cleaner, Retrorides has also fitted the rear turn signals, which are made from clear acrylic. Greater attention to detail gives this K100 a smooth and engaging visual flow.
“At this point, the design is essentially complete,” says Gustavo. “So it’s time to start with mechanical parts and details.”
The stance is crucial, so the crew starts with the wheel. They took a pair of 17-inch rims, finished them in bronze, and adjusted the rear wheel deflection to match the frame. The tire chosen is the Heidenau K73s, a particularly durable compound originally designed for supermotos.
The new brake rotors are CNC manufactured and feature new four-piston brake calipers at the front. They are mounted to the USD fork of a Honda 599/Hornet, which is coupled using three new top and bottom rods made from CNC machined aluminum.
“With the handlebars, we decided to do something different,” says Gustavo. “We have reversed the crossbars on the top of the headlights.” The result is good: none of the free space you get with clip-ons.
CNC aluminum mirror and discreet Motogadget The turn signals are mounted on the handlebars, and Retrorides has also made a stand for a Motogadget Motoscope Mini speedo.
Much heavier work is evident on the back panel, notably the new subframe machined from aluminum. Following the contours of the fuel tank, it is plated in black. It also hides a compact lithium battery and supports new seat cushions, upholstered in black leather with diamond stitching.
Underneath is a new horizontal rear suspension, designed and sold by Retrorides and popular in the custom K series segment. Designed for monolever bikes and machined from a solid block of aluminum, it also ‘opens up’ the back panel visually.
The engine requires little work: with about 90 hp on tap, it has enough power. However, a new stainless steel exhaust system helps to release the breath, and Retrorides has machined four eye-catching speed stacks on the intake side.
The subtle gray BMW bodywork contrasts with the black finishes elsewhere, with additional accents from the bronze of the wheels and intakes.
It all ties together beautifully and that makes it one of the best K-series customs we’ve ever seen. Gustavo and Rodrigo made their father proud.