The Harley-Davidson Gravel Gorilla Is A Beastly Fat Bob You Need To See

Gorillas are commonly thought of as a quiet species that minds their business and exists peacefully. But dive a little deeper, and you’ll find out they’re some of the most ferocious animals in the world. They can fight hard, destroy jungles, and take on bigger predators if push comes to shove.

So when popular shop Purpose Built Moto wanted to whip up a beastly custom motorcycle based on a cruiser, it couldn’t help but take inspiration from the primate. The result? The Harley-Davidson Gravel Gorilla. It’s based on the Fat Bob but armed with upgrades from head to toe, transforming the cruiser into a ferocious street tracker. Here’s what you need to know.

The Harley-Davidson Gravel Gorilla Looks Nothing Like The Fat Bob

In its standard form, the Harley-Davidson Fat Bob is a big and burly cruiser. Wide fenders, a curvy tank, and slot-like alloy wheels all give it a distinct appeal like no other Harley-Davidson out there. But for the Gorilla avatar, Purpose Built Moto has stripped things down. Gone are the chunky stock fenders and in comes new, smaller units at each end. We particularly dig the neatly done tail that comprises a chopped-off subframe, a swingarm-mounted plate holder, and flat track-like, minimalistic plastics. This tail also paves the way for a new saddle, visibly a lot slimmer than the stock seat with no space for a second occupant.

What further elevates things is the set of 17-inch spoke wheels–an inch larger than the OEM setup. These flex candy copper spokes and blacked-out rims for a distinct look, while being wrapped in beefy Pirelli MT60RS dual-purpose rubber. Rounding off the aesthetics is the custom livery. Although predominantly black, the bodywork has gray pinstripes and copper leaf detailing for a likable contrast. The end result is a motorcycle that looks nothing like the Fat Bob, with the only giveaway being the rectangular headlight.

The Harley-Davidson Gravel Gorilla Boasts An Upgraded Milwaukee Eight Engine

Diving deeper, the upgrades only get more serious under the skin. The Fat Bob’s Milwaukee Eight 114 (1,868cc) engine has been upgraded with a Stage 3 Screamin’ Eagle kit. This, along with a full system two-into-two Werkes exhaust, bumps the output to over 110 horsepower and 90 pound-feet (on the dyno). The stock bike makes around 90 ponies and 110 pound-feet at the crank, for reference.

The bumped-up power reaches the wheel via a chain drive instead of the stock belt-driven transmission. Also, you’ll notice the engine looks much different, too. That’s courtesy of an entire suite of Arlen Ness x Rough Crafts engine covers.

Next up, underpinnings. Purpose Built Moto had a task on its hands here, as the motorcycle’s owner wanted a do-it-all custom bike. A bike that could take on rough terrains, while still being every bit a Harley-Davidson. The shop owner explains:

The conversation started with building him a custom Harley-Davidson that would suit his newfound riding love. Our rider found himself on destination-less rides, often staying out overnight after winding his way down gravel roads for the day. His needs involved creating a better handling motorcycle, retaining an upright ‘all day’ riding position.

To achieve that, the team has raised both ends of the motorcycle. The stock upside-down forks are now an inch longer than before and boast an Ohlins cartridge kit to boost performance. Whereas, the rear shock is all-new and 3.5-inch longer than the stock. Like the suspension, the brakes undergo an overhaul as well. The stock rotors and calipers have paved the way for a set of petal rotors, clamped by upgraded Brembo calipers. Bonus points for the black-on-red finish of the calipers. Last but not least are the new wheels we’ve already mentioned above.

You Can’t Buy This Custom Harley-Davidson Fat Bob

Tempted after seeing this one-of-a-kind Fat Bob? Then, you’d be sad to know this example isn’t on sale. As mentioned, the Gravel Gorilla has been built for one of Purpose Built Moto’s regular customers, who’s likely having a blast aboard it. However, if you’re looking to get a similar motorcycle for yourself, we’d suggest getting in touch with the shop directly.

Its portfolio comprises all kinds of custom builds–cafe racers, flat trackers, or simply a resto-mod–so the donor bike can be anything of your liking. In case that’s too big a step, you can also go through PBM’s extensive accessories catalog for some small but stylish upgrades. It also sells entire DIY kits if you don’t mind getting your hands dirty.

Source: Purpose Built Moto, Pipeburn