Biltwell's 08 Triumph Bonneville R&D Mule


“Hey McGoo—want to modify a Bonneville for some Brit bike shows this summer?” When Billdozer floated his idea between the walls of our offices, I took it more as a friendly request than an absent-minded inquiry. After watching me fiddle with my finicky Hinckley chopper for two years, Bill probably thought I was ready for an easy win. What could be easier than stripping a stock Bonnie of its bloated, EPA-friendly essence and turning it into a fire-breathing street flier? Twenty-four hours after hearing Bill’s question, I was about to find out.



Biltwell followers on Facebook may be familiar with Bill’s EZXL projects. Both the dirt and street versions of his Mr. PotatoBike boasted a stripped-down look that appealed to me as soon as I watched them unfold. Rather than tackling fab tasks or chasing custom dragons he doesn’t have the tools to slay, Bill champions the notion of “beautification by subtraction.” This contradicts what the girl at the Harley parts counter wants us to believe, but Bill is right: less is more. Bill reckoned if we applied the same strategy to a modern Triumph, it might expand Biltwell’s relevance to the growing legion of bikeriders who love these machines, this Triumph owner included. I was in. 


The donor bike for my EZ-T100 was a 2008 Bonneville with 10,000 miles, one of two on Craigslist in the greater SoCal area. Twenty-four hours after Bill floated his idea I drove to San Juan Capistrano Yamaha to pick her up. The previous owner had dodged the PCV system hidden under the gas tank, but everything else on the bike was stock. In an flash I threw the ’08 Bonnie into stripdown mode. Wheels, tins and cockpit components came off first, followed by side panels, air box and exhaust. In a moment I would rue two months hence, I blindly burrowed into the Bonnie’s electricals, wrenching out every wire, brain box and gizmo that wasn’t sonically fused in place. All totaled my chainsaw surgery trimmed over 50 pounds of flotsam and jetsam from the mothership. Of course I had no idea if the bike would run again, but I would worry about that later. It was time to rebuild the wheels.


Whether right or wrong I have a theory about building custom motorcycles and it stipulates that wheels and tires set the stylistic tone for everything else on the bike. For my EZ-T100 I wanted a set of semi-studded multi-surface tires like the ones on BMW adventure bikes and street-legal supermoto machines. The 18-inch Pirelli Scorpion I chose for the rear wheel demanded a new rim, but I wanted to run black anodized Excel alloy hoops anyway, so I pulled the trigger. Unfortunately, Pirelli didn’t offer a matching tire in the 110/90-19-inch size I needed for the front. Kenda did, however, and its tread block complemented the European meat I’d selected for the rear nicely. While I waited for Buchannan’s to custom drill my Excel hoops and cut spokes to match the stock Bonnie hubs, I moved to the easy task of refreshing the cockpit.



A pair of Biltwell Moto bars trimmed 5/8-inch on both sides, mated to a black Biltwell Thunder riser took no time to install, and only required one modification: drilling half-inch holes through the metal washers that are fused onto the rubber isolators inside the Bonnie’s triple tree. I slid the stock hand controls onto the bars to eyeball my handiwork, and decided immediately that leaner controls were required. A call to Joker Machine got the ball rolling on a J-Tech billet alloy master cylinder and matching mechanical clutch lever. To save me money the good folks at JM sold me scratch-and-dent blems from the billet bone yard. A trip to my local plater was all it took to get the mix-and-match parts the same stealthy black. A Biltwell Whiskey throttle completed the cockpit, but now I desperately needed help with the wiring…I’d just torn the original loom and associated switches to shreds jettisoning the stock headlight and switchgear. Fortunately some smart cookies on ChopCult pointed me in the right direction for a stripped-down T100 wiring diagram on my build thread



Jason and Sean at British Customs in Gardena, California, are crafty Brit bike gurus in their own right, and good Biltwell customers, to boot. A visit to Sean got me on the right track for an air box/battery case to replace the restrictive stock unit. The BC air box eliminator came with everything I needed to junk the stock box: an alloy battery box, two K&N filter pods and jetting to let my asthmatic girl breathe. These things fit nicely behind the stock side covers, but I didn’t like how the bodywork covered BC’s upgrade, so I drilled two holes in each cover and shaped some stainless steel screen to make them look racy. The finished side panels turned out even better than I expected, and cost less than ten bucks for materials. If you’re looking for something fun to do to your own Bonneville, this mod is a great place to start.


During my visit to British Customs, Jason and Sean lamented the dearth of cool-looking aftermarket seats available for Hinkley Triumphs. To fluff up Biltwell’s range of bolt-on seats into Triumph territory, I enlisted Duane Ballard to help us design a two-up café seat that eschews the bread loaf bulkiness of current stock and aftermarket offerings. The seat on the EZ-T100 is a custom-upholstered leather affair that mimics the foam shape and double diamond stitching as closely as possible to the one Biltwell will introduce later this year.



Buchanan’s was on time and under budget on the rims and spokes for my refresh, so I built the wheels and shod them with my tires from eBay. She was a roller again, but still in need of tweaks to look solid. Enter Dave Zemla at Burly/Progressive. A set of 12.5-inch Model 444 shocks and a Burly fork spring kit compensated for the taller wheel/tire package nicely. Still, something was wrong. After eyeballing the bike in side profile I determined the muffler mount/buddy peg brackets had to go. After some cutting, welding and grinding my chassis was complete. I shipped the tins to Josh Scott at Old School Helmets for the metrosexy paint and asked Duane to order the special skins for my seat. The deadline to ship this bike to its first show in Chicago was looming, and I was scheduled to disappear for two weeks on the 2013 EDR. If this beast was going to run, I would have to do it myself—passing the buck was not an option.



After staring at that damned wire diagram for two weeks, I finally grabbed my soldering iron and went to work. After three evenings and one weekend I hooked up the battery and gave the relocated key a twist. Miraculously, it fired, and without a gas tank or exhaust system in sight! I don’t know what I did, but apparently it was right. With a week to go before my Baja departure, I rejetted the carbs according to British Custom’s specs and waited for Duane and Josh to finish their contributions to the project. On the Saturday before Otto Von Blotto’s departure to Mods and Rockers June 11, Duane installed my seat and I test rode the EZ-T100 for the first time. Talk about cutting it close.



As an exercise in skunkworks R&D the EZ-T100 was a huge success. While it tested my patience for oppressive deadlines, it also broadened my wrenching skills on these modern machines. I no longer fear electrical and carburetion systems on new bikes and that's a good thing. I couldn't be happier with the distinctive look of my stripped down T100 and thanks to Progressive, Burly, British Customs and Joker Machine, it runs like a champ. I get to ride it again for the second time at the Lowbrow Getdown July 12-13, and I can’t wait.


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Commented on 6-13-2013 At 07:12 am

Love the McGoo writing styles

Commented on 6-13-2013 At 07:53 am

This makes me want to tear my new Triumph apart!

I am, thanks to H. McGoo, running an official Biltwell Thunder Riser on it though...

Great looking bike! Came out killer. The seat is killer, and I'm stoked Biltwell is going to produce a seat. My boogie board seat has a ton of miles on it, chapping the shit out of my tight ass.

Commented on 6-13-2013 At 07:57 am

Can't wait for the seat Biltwell has to offer is available. Are the foot pegs going to be available as well?? Bike looks outstanding.

Commented on 6-13-2013 At 08:41 am

This came out nice, well done my friend...

Commented on 6-13-2013 At 09:21 am

congrats on the feature. looks awesome

Commented on 6-13-2013 At 09:21 am

congrats on the feature. looks awesome

Commented on 6-13-2013 At 12:53 pm

great job McGoo...the bike looks slick. I feel your pain on the electrical side of things

Commented on 6-14-2013 At 04:23 pm

Sweet machine!

Is there a maker of "classic" Triumph-style petrol tanks for new-style Bonnies which don't have that Japtastic FLANGE sticking out around the whole tank?

I bet they could sell a lot of them.

Commented on 6-14-2013 At 11:22 pm

Hey, it's the MarthaStewart Edition Triumph! Not that that's a bad thing, actually.

Hey, farmall if the tank is being painted some hammer-foo can be applied to the flange before paint. Knee indentions too, if desired, with more hammer-foo.

Commented on 6-14-2013 At 11:26 pm

Since Triumph did a Golden Jubilee Triumph for queen Elizabeth..why not.
Could be celebrating Martha's release from jail..

Commented on 6-16-2013 At 11:03 am

Love the bike,hate the seat.

Commented on 6-16-2013 At 11:06 am

Love the bike,hate the seat.More specifically,the seat colors.

Commented on 6-16-2013 At 09:23 pm

Saw it in person at Mods vs. Rockers, very cool bike, and an awesome write up.

Commented on 7-15-2013 At 07:58 pm

Seeing this bike makes me really want to get those bars and clean up the front of my bike w/ a new headlight and gauge.

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