Kai from Lastenrad-Tuning: 240 ideas, one 3D printer, and a Christmas gift that started it all

When I started opencargo.bike, I didn't really have a clue of what was out there. I did a bit of research but somehow missed Kai's website. Lastenrad-Tuning. Then I realised two things. First: wow, this is the ultimate community contribution we could ever dream of. And second: he deserves a full maker page for himself.

That's why it's so exciting to build opencargo.bike. It's discovering we're not alone, crazy cargo bikers. We're all out there, silently making a difference to make our cities a better place.

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Kai's cycling story started in 1986. Mountain biking first, then cycle touring, commuting to university, using bikes for everything. After 26 years as an engineer at Mercedes-Benz, he bought his first electrified bike, an Omnium E-Cargo, and it replaced his company car completely.

It soon became my daily vehicle for all daily tasks.

But he couldn't leave it stock.

Different grips with inner barends, fixed lights, a rear rack, custom mounts for Euroboxes. Pretty soon it became 'my' bike.

Then came Christmas. His family gave him a 3D printer. Or as he puts it: "I think my son-in-law was just tired of me keeping him busy printing for me non-stop."

Around the same time, he started selling cargo bikes professionally. Every customer had unique needs. Transporting a cello. A dog that needed to be secured in the middle of the box. Billboard mounts. He started designing prototypes, and noticed that many requests repeated themselves.

That's when the idea for a website struck: to make these ideas accessible for everyone.

He structured lastenrad-tuning.com by brand and load type, added search and filters. Once the first 50 ideas were online, riders started sending in their own photos, adaptations, and improvements. That's how the "Readers Rides" and "Readers Ideas" sections appeared.

Today: over 240 ideas, 50+ brands, and contributions still coming in.

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I asked Kai what he notices about the differences between platforms, how some bikes seem to invite modification more than others.

His answer was simpler than I expected.

I think the main difference isn't the bike itself, but the rider. Some people buy a cargo bike simply as a practical solution. Others see their cargo bike as another project for personalisation and optimisation. They enjoy the process of modifying and improving. For them, riding and tinkering belong together.

Or the simple answer: some people love to build things, others don't. There's space for both.

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For anyone who just bought their first cargo bike and maybe has a 3D printer gathering dust in the garage, Kai's advice is disarmingly practical:

Start by just riding and enjoying it! If everything works fine, there's no need to waste time and print parts you don't need. But if you notice something to improve, there's a huge knowledge base online. Check sites like opencargo.bike, lastenrad-tuning.com, or forums such as cargobikeforum.de. Reddit communities are also useful.

If you can't find what you need, ask around, or design it yourself! And when you've built something great, share it. Send me pictures and details, and I'll be happy to publish it as a Reader's Idea. That way, everyone benefits from your creativity.

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What keeps him going after all these years?

Cycling has been part of my life for decades and helped me through tough times. It's more than just transport. It's freedom, sport, nature, community, therapy, relaxation, and anything else you can think of.

The ideas keep coming, and sharing them with others who actually use them is incredibly rewarding. And the cargo bike community just grows stronger when experiences are shared.

His newest project: helping establish a local cargobike-collective.org group in Stuttgart.

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But Kai's story goes deeper than a website. Matchbox cars in the sandbox. Lego Technic. RC model building. Eventually the vehicles got big enough to drive. One of the first mountain bikes available in Germany in 1986. And a driver's licence. But while he outgrew the Matchbox cars, bicycles and cars stayed.

For 26 years at Daimler, he developed cars. Lightweight body construction, pedestrian protection, functional validation, electrification, digitalisation of production planning. Designer, analyst, test engineer, project leader, team leader. "The best or nothing" wasn't just a slogan. It defined the work.

Then Corona. 2020. Plenty of time to reflect. Personal changes, new challenges, children now independent. And at the beginning of 2021, the decision to resign after 26 years. A strange feeling.

Since October 2021, a completely new life. As a consultant at LadeHero CargoBikes, he turned the hobby into a profession. And because, as a "half-Swabian," he can't resist tinkering, the transport questions keep occupying him outside of work. And one or two of them find their way onto lastenrad-tuning.com.

In his own words:

Even though bicycles can't completely replace private cars, and certainly not freight transport, they can contribute to the mobility revolution and a more livable future. You simply have to try it out and experience for yourself how much fun it is. I'm happy and proud to be doing my part.

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You can find all of Kai's products on his maker profile on opencargo.bike, browse the full 240+ idea collection at lastenrad-tuning.com, or visit him at LadeHero CargoBikes in Stuttgart.

Kai's approach is exactly what opencargo.bike is built on. Independent makers solving real problems, sharing what they learn, and making the whole ecosystem better for everyone.

It's the same story I heard from Susann at rad3 — different workshop, different city, same instinct to tinker. Two engineers who left big companies to build things that actual riders need. There's a pattern here.

But the long john gives builders something to build on. That matters. Read why I think the long john format is the reason this aftermarket exists →

Powering cargo bikes, powered by the community.

— Vince

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