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Fat SR: A chunky Yamaha SR400 from Greg Hageman

Fat SR: A Yamaha SR400 custom from Greg Hageman
Like all good artists, the best custom builders have a handful of regular customers. They’re usually folks with an eye for quality and shared tastes, and they’re gold dust.

Iowa-based Greg Hageman has been in this business for many years now, and one of his most steadfast customers is Mike Martens. ‘Fat SR’ is the fifth bike that Greg has built for Mike over the years, although it’s really for Mike’s partner Sally.

Fat SR: A Yamaha SR400 custom from Greg Hageman
“This bike is a 2015 SR400 that I purchased for myself,” Greg tells us. “But Mike was looking for a bike for his girlfriend to ride, and I ended up selling it to him. Kinda wish I had kept it—they are hard to find for a decent price now, since they discontinued them here.”

‘Fat SR’ is a classic example of moderate tweaking having a massive effect, so we were intrigued to see how Greg managed to make the humble Yammie look so good.

Fat SR: A Yamaha SR400 custom from Greg Hageman
He started by stripping everything off to take a look at the bones of the machine. “I cut the rear of the frame off, made a bolt-on hoop unit, made up a seat pan, and shipped it out to my friend Chris at Tuffside for upholstery. Then I stenciled a Yamaha logo on the back of the seat.”

The tank was entrusted to a local painter, Joe Manley. He laid out a Candy blue color and a retro stripe that Mike had decided on—inspired by the early 70s Yamaha AT3 enduro color ‘Brigade blue.’

Fat SR: A Yamaha SR400 custom from Greg Hageman
Greg and Mike decided to go for the fat tire look, so they got Buchanan’s to lace stainless spokes to 16×3.5 alloy Takasago rims.

After the hubs and rims were powder coated satin black, Mike found some raised white lettering Dunlop 491 Elite II tires—140/80 for the rear and 130/90 for the front.

Fat SR: A Yamaha SR400 custom from Greg Hageman
“The front tire was a tight squeeze,” Greg admits. “We considered swapping out the front end, but instead I machined the original fork legs so I could keep a front fender on it. I made some alloy fenders, and had them powder coated metallic silver similar to some early 70s Yamaha models.”

To tighten up the handling, the SR400 forks have new internals from Race Tech, including upgraded springs and Gold Valve Cartridge Emulators.

Fat SR: A Yamaha SR400 custom from Greg Hageman
Mike ordered YSS shocks from Europe, and with the help of a friendly contact, got a one-off set custom made and set up specifically for the bike. The front fork gators are from Motolanna, and much better quality than the original plastic units.

The exhaust is simply a stock header pipe with a slip-on muffler that was modified to fit. “We wanted something different, so Mike found an alloy can with good baffling, from France. We both hate loud singles because they tend to sound like a big lawn mower, so proper baffles are a must for sound and performance.”

Fat SR: A Yamaha SR400 custom from Greg Hageman
For electrics, Greg has ditched the stock instruments and installed a clean, simple Koso unit. “I also made some tiny LED turn signals on my lathe. The headlight and taillight are Bates-style units with LEDs installed.”

The stock foot pegs were cut off and replaced with Tarozzi foldable pegs, but the passenger pegs remain in-situ for occasional use.

Fat SR: A Yamaha SR400 custom from Greg Hageman
After trying on a pile of different bars, Greg and Mike ended up sticking with the stock items. “We also kept the stock switches and levers, but installed a set of Vans grips,” says Greg.

“The whole idea of this bike was to keep the relaxed riding position. Anyone who’s ridden an SR400 knows the power plant is anything but aggressive—so you may as well just go with it, and enjoy the ride.”

Fat SR: A Yamaha SR400 custom from Greg Hageman
“The fat tires and great suspension all help with the smile per mile combination. And the 60+ mpg doesn’t hurt either!”

Client Mike is also happy, and reckons the SR is a rolling testimony to Greg’s underlying aesthetic: make it sexier, and create the illusion of a factory build.

It’s a philosophy we can get right behind too.

Hageman MC | Facebook | Instagram | Images by (and with thanks to) Don Gawf

Fat SR: A Yamaha SR400 custom from Greg Hageman