Triple Time: BMW K75 Custom Roadster

WiMoto’s BMW K75…

Introduced in 1986, the BMW K75 was the triple-cylinder 750cc version of the Flying Brick, featuring dual chain-driven overhead camshafts, two-valves per cylinder, liquid cooling, and Bosch LE-Jetronic injection like the four-cylinder K100:

“The K75 was essentially a K100 with the front cylinder missing, and a pair of balance shafts in the engine to quell vibration from the rocking couple of the triple’s 120-degree crank. And like its liter-class brethren, what impressed testers at the time was how BMW had managed to preserve the character of their boxer twins…’civility, simplicity and excellence.'” –Motorcycle Classics

Despite the smaller displacement, the 750 triple became the sport bike of the K series. The K75 actually made 10% more horsepower-per-liter than the K100 thanks to hotter 11:1 pistons and other tweaks, and many riders came to prefer the K75 thanks to its lighter weight, quicker-revving engine, and sportier nature.

“It sharpens that special BMW experience, and, with better control, elevates it to a higher road speed.” –Cycle

Enter our new friend Wido Veldkamp, who cut his teeth as chief engineer of the Novabike Racing Team at Delft University of Technologies before starting his own company, WiMoto, ten years ago. In that time, his shop has earned a reputation for engineering excellence among the motorcycle community:

“Most of the time we do engineering work, and a lot of structural welding work, like building frames, swingarms, subframes etc…now and then we also do complete customs.”

In this case, Wido’s friend Kirsten had already bought, dismantled, and sourced a number of parts for her 1990 BMW K75.

“She didn’t have the ability to weld so she came to me. And this evolved into us doing the entire build.”

The entire build was done on a tight budget, and it was a relatively simple build in terms of the WiMoto skillset — after all, Wido usually builds components like the swingarm from scratch (see his Honda CBR600F2 Cafe Racer in our classifieds for an example). However, the WiMoto excellence shines through in this project, especially in the tail of the bike. Says Wido:

“I always dislike the original lines of the K-frames, especially the customs that just put a hoop at the end and make a custom seat that follows the lines of this original frame. We completely chopped down the rear frame and build it new to follow the seat exactly! I personally really like that the tail light is integrated in the frame.”

Other highlights include the Aprilia Tuono forks with mammoth 320mm brake discs, custom fender and radiator covers, hidden electronic components, and lots of powder coat. This K75 looks a treat, and more importantly, Wido says the bike handles incredibly well considering its heft.

“The client did not recognize the bike at all after her first test ride. ‘Much better,’ she said. ‘It feels 50kg lighter!'”

Below, we talk to Wido for more details on the build, with photos courtesy of Mark Meisner.

BMW K75 Café Racer: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

My name is Wido Veldkamp, I studied Industrial Design Engineering at Delft University of Technologies. Been running my company WiMoto now for 10 years! I’ve been working on scooters, mopeds, and motorcycles since I was a little boy.

But I started my company after I was chief engineer at the Novabike Racing Team at TU Delft and got a lot of encouragement to start my own business. We are now 10 years in business, and most of the time we do engineering work, and a lot of structural welding work, like building frames, swingarms, subframes etc. And so now and then we also do complete customs.

This was the case for this BMW K75. A friend already started with dismantling this thing…but she didn’t have the ability to weld so she came to me. And this evolved into us doing the entire build. Of course we had to do this on a budget, so there are things we would have normally done different (for example the controls on the handlebars are still original), but yeah budget is always an issue….

• Please tell us a bit about the bike.

As I said, the owner “Kirsten” of this 1990 BMW K75 already started by dismantling the bike. She already bought some parts, the seat and headlight and a speedo indicator. But when it came down to welding the frame she needed some help. One thing lead to another and eventually we did the entire build… Although it looks like a quite standard K75, a lot of modifications took place.

The frame was modified to fit the rear end she really liked. Take a look at how the frame is bent upwards compared to the original frame. We didn’t only weld on a simple hoop — the entire rear-end was made from scratch, including the integrated taillight that is placed inside the frame. With a fresh new fine texture black powder coat this frame is better than ever!

We modified and placed an Aprilia Tuono front fork to give it a more sporty look and better handling! Combined with adapters for the massive 320mm brake discs, this bike feels amazing! The brake calipers are powder coated a contrasting color to the blue/green paint job. A custom front mudguard and some radiator covers complete the overall look.

The electric components are all placed inside the rear frame, so we have a nice open space where normally the battery is. A custom license plate holder was made including indicators to keep a clean rear end. Everything on the bike is freshly powder coated or painted, new tires, new brakes, brake lines, complete serviced engine. This bike is ready for the road.

• Can you tell us what the finished bike is like to ride?

Because we swapped the front end for an upside down unit that is a little shorter than the original forks, the geometry became a little bit more sporty. With a castor of 25 degree and a trail of 100mm this thing now feels quite nimble, although it is still a heavy bike!

We made adapters for the massive 320mm discs, which improves the overall feeling of control substantially. The client did not recognize the bike at all after her first test ride. “Much better,” she said. “It feels 50kg lighter!”

• Was there anything done during this build that you are particularly proud of?

I always dislike the original lines of the K-frames, especially the customs that just put a hoop at the end and make a custom seat that follows the lines of this original frame.

We completely chopped down the rear frame and build it new to follow the seat exactly! I personally really like that the tail light is integrated in the frame.

For WiMoto, this was just a quite simple rebuild in terms of level of difficulty; we normally build the swingarm etc. ourselves. But we already have a lot of good reactions on this build, so I think this is what mainstream custom lovers like to see.