KTM-powered “Monster Chopper” gets hydraulic steering

It’s the work of the Grind Hard Plumbing Co. team. We assume at some point there might have been some actual plumbing going on amongst these lads, but after finding viral success stuffing a Honda engine into a Barbie car back in 2018, it seems YouTube has become a primary focus for this small gaggle of talented lunatics.

They’ve since built the world’s fastest snow bike, the world’s fastest shopping trolley, a 100-horsepower micro jet boat, a giant RX7 rotary-powered drift trike, “the ultimate off-road Tesla” Model 3, and all manner of other nutty stuff, garnering 360 million-odd views in the process.

Grind Hard’s latest project is an attempt to cross-breed a motorcycle with a monster truck. It’s based around a KTM 1190 Adventure V-twin engine, making somewhere around 150 hp, and a pair of comically massive 46-inch wheels with heavy-duty mud tires on them, held together with a giant – and surprisingly nicely crafted – steel tube trellis frame, with a pair of single-sided swingarms suspending the wheels.

Off Road Chopper Build on 46” Mudders! KTM 1190

“The goal here is to build the most absurd, Mad Maxy, apocalyptic choppery thing ever, with a beautiful engine,” says Grind Hardist Ethan Schlussler. “Is it going to perform well? Almost certainly not. But it’ll be really entertaining to try.” And while its two enormous wheels and huge wheelbase might immediately call to mind the Batpod from Chris Nolan’s The Dark Knight, Schlussler wanted this to be a lay-back chopper instead of a … whatever the Batpod is.

Of course, since the front axle sits nearly as high as the raised handlebar, a traditional telescopic fork and direct steering head isn’t going to do the job. And the sheer size of the front wheel means you’ll need some serious leverage to turn it. So the team decided on a hydraulic steering system, with lines routed along that nicely curved front swingarm assembly, a drive piston actuated by the handlebar, and a slave piston near the wheel hub.

The team used narrow-gauge hydraulic lines for some early experiments, resulting in a rather extreme steering damping effect and a scary delay between the handlebar and the front wheel that one off-camera team member dubbed “the closest thing to Bluetooth steering I’ve seen in my life.”

Masive steel-tube trellis frame and swingarms.  Grind Hard Plumbing Co.

With larger lines fitted, steering response was adequate enough that Schlussler decided to take it out for a test ride. With the motor still yet to be hooked up, drive was supplied by a small, steep hill just outside the workshop.

How’d it go? Well, the suspension did a pretty decent-looking job… The steering? Well, it worked to a degree, but the fairly flat profile of those huge mud tires made it very hard to get the bike leaned over. As a result, Schlussler ran it into a fence post. Final score: Monster Chopper 1, fence post 0.

Hydraulic Steer Monster Chopper Build!

The bike is undamaged, and the project continues. We look forward to seeing it complete, and being taken to “full send” in a subsequent video. Godspeed Grind Hard Plumbing Co., you marvelous bastards.

Source: Grind Hard Plumbing Co.  View gallery – 6 images



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