Mule Streetmaster Triumph Bonneville

Triumph Bonneville custom
The king of street trackers is Richard Pollock of Mule Motorcycles. He’s spent over two years designing and building his latest bike, the ‘Streetmaster’—and last weekend, finally unveiled it to an enthusiastic crowd at the Quail Motorcycle Gathering in Carmel, California. Richard sent in a little background, so here you have it from the horse’s mouth:

“The project is the brainchild of [Triumph fanatic] Richard Varner. His vision was to build a Triumph street tracker using the current Bonneville motor in a lightweight chassis, while keeping a traditional Triumph street tracker look: High tech, but not too modern in appearance, with an increase of horsepower to over 70 at the wheel. And an all-up weight of 300 lbs (136 kg). The motor would be given a power boost by Triumph engine builder Charlie Barnes, and I would handle the chassis to house it in.

“The end result was over 75 hp to the wheel, powering a package somewhere between 300-308lbs. The motor has retained the stock cylinder and pistons and runs on pump gas, despite a roughly 50% increase over the stock rear wheel hp! The motor weighs almost 200 lbs, so that didn’t leave a lot of wiggle room for achieving a 300 lb overall weight. I was staring at a window with a small opening: a rolling chassis with battery, lights, electrics, brakes and exhaust, and it had to come in at 100 lbs. So right up front, I knew it wouldn’t be easy or cheap. There would be titanium, carbon fiber and lots of trial and error involved before we could get the jump on gravity.

“The end result? We have an extremely light chromoly frame with an aluminum tank and lightweight carbon seat shell. Components include Penske twin shocks, Speed Triple 45mm forks, a small battery from a 650 Suzuki, a billet oil cooler mounted below the fuel tank, Wood Racing stainless handlebars, KTM Brembo master cylinders and then the titanium. Lots of it: axles, the exhaust system, every nut and bolt, Ti brake rotors with a ceramic coating, lightweight brake lines, and Ti spokes fitted to tubeless wire wheels. Holes are drilled everywhere, with all components weighed prior to assembly. There was a continual search for a lighter solution. As amazing as it sounds, it could be lighter still.

“The motor received extensive gas flow work, cams, a programmable ignition, valves, springs, and 39 mm FCR Keihin carbs—and lost 13 lbs (5.9 kg) from the crankshaft. A huge amount of work went into the development of a billet primary cover using a KTM hydraulic clutch master cylinder. It improves accessibility for clutch servicing through a small removable side cover, and gives a weight saving of 2.75 lbs. Best of all, the looks of the bulky engine have been totally transformed into a motor that is pleasing to the competition-minded eye!

“The long-term plan is to build a run of similar bikes, scaled back on the use of titanium for a more standardized ‘Production’ version. Weight will still be very light and when combined with a selection of motor parts being developed, this will be the bike Triumph should have built!” says Pollock.

With 75 hp pushing just 300 lbs, this bike will go like a scalded cat. If Pollock can productionize it at 150 kg (330 lbs) without the expensive titanium, I reckon there will be a queue knocking on the Mule Motorcycles door. [Thanks to David Folch for the first image and Richard Pollock for the other shots.]

Triumph Bonneville custom
Triumph Bonneville custom
Triumph Bonneville custom

  • http://www.car137.com Glenn Edley

    The King is right. Mr Pollock has done it again. I have a goal to get him to build me a street tracker with a Harley motor. Saving up now.

  • http://www.real-bikes.com Nick

    Simply fantastic! I like it so much.

  • jheath

    Great bike but a strange kind of progress.

    A Meriden Bonneville weighed 375 lbs, had a passenger seat and practical tank capacity.

    A Hinckley is practical but weighs 450lbs.

    Hats off to Mule for 308lbs — fantastic ride. However, it’s not a day-to-day bike and I can’t think what it cost.

    Why can’t they make an air-cooled twin that weighs less than a fourty-year-old Meriden, with passenger seat and normal tank, for a decent price?

  • deniro

    With 75 hp pushing just 300 lbs, this bike will go like a scalded cat. If Pollock can productionize it at 150 kg (330 lbs) without the expensive titanium, I reckon there will be a queue knocking on the Mule Motorcycles door.

    YOU CAN SAY THAT AGAIN!! FABULOUS1111

  • jason

    jheath,

    look at a buell lightening, 92hp, twin, air cooled, something for a passenger to try to sit on (Unless you get a xb12ss or xb12st, longer better passsenger room), and the xb9 weighs in around 380… Not horrible.

    Love this guys work. I would like to see more pictures of his shop set up, looks like it’s pretty nice too.

    Jason

  • 4Cammer

    Begining to think this fella at Mule knows what he is doing…that is a really fine bike sir.

  • http://www.esands.com Graham

    Where do I sign???

    I will be contacting Mule to keep me informed re progress of a possible ‘production’ version – and getting one to me in Australia.

  • Eskild

    Great bike and perfect proportions! wouldnt mind some more pics(in colours?)

  • Dawg

    Sounds like they are gonna be busy at Mule, and deservedly so.

  • Aaron Burke

    Ouch! That is white-hot, that’s how hot it is. Makes me badly want to ride fast and turn left.
    The clutch and cover is fantastic, hope they retail that. I can see it being a big hit for them.

  • joel pachuau

    very very nice….

  • http://grandnationalreplica.com Todd

    I still prefer the Grand National – More V twin power with about the same weight.

  • http://www.mulemotorcycles.net Mule

    Todd, I’m not so sure the GN comes in at close to the same weight. I’ve built about 60 of the Harley based ST’s and the lightest ever was about 365. The XB motor is lighter than a Sportie or early Buell motor, but they still weigh a ton! An XR750 weighs over 330 and thats about the lightest HD twin there is.

    Can’t argue with the V-twin feel though.

  • http://sunmusicproductions.com sun

    Wow….speechless…

  • Teff #79

    That is awesome,
    No-one over here in the uk has built a flat tracker so cool