The term sigma is used to describe a non-conformist individual. Someone who identifies as an outlier and does things their own way regardless of societal norms and expectations.
For their latest custom build, Spanish workshop Tamarit created a motorcycle that embodies the sigma persona. A motorcycle that shamelessly blends styles and unapologetically places form before function. In keeping with this approach they named the heavily modified Triumph Bonneville T100, Sigma.
Tamarit Motorcycles are unequivocal experts when it comes to customising Triumphs. This T100 is the 138th bespoke Triumph to roll out of their workshop and as you’d expect by now they’ve become rather good at it. Along with producing their own range of Triumph aftermarket parts, Tamarit uses premium parts from its preferred suppliers on each project, and Sigma is no exception.
For this bike, go-to parts supplier Motogadget contributed a Motoscope Mini Digital speedometer which leaves this bike’s cockpit looking minimalist and clean. Motogadget were also responsible for the discrete turn signals, keyless ignition system and the M-unit Blue electronics control module which is the brain of the bike’s electrical system. A modern LED headlight upgrade was par for the course and here it’s been complemented by an LED tail light which is built into the frame loop.
Sigma also wears a set of straight drag handlebars which pull the rider forward and establish a more aggressive riding posture. They wear discrete switch blocks, a custom throttle, aftermarket grips and a chrome plate brake reservoir. The new levers hail from Kustom Tech and a set of Motogadget bar end mirrors complete the new look. Tamarit has also machined its own triple clamp for this project and installed a set of their Pantera springs to the fork stanchions. Although they look functional, the springs are purely aesthetic, but the visual benefits they deliver are undeniable.
In the rear, you’ll find more Tamarit equipment in the form of a hugger-style license plate mount. Out front, they’ve performed a small fender conversion, hung a Hummer sump guard under the front of the engine and there’s a trick Tamarit chain guard replacing the bland factory part.
Another customary Tamarit tweak is the modification of the Triumph chassis. In this instance, the stock subframe has been replaced with a shorter hoop which tightens the Bonneville’s proportions. The new seat only has room for one and has been shaped to match the dimensions of the new hoop. What makes it really special though is how the seat reaches up onto the fuel tank, tying the two components together to form an insectoid-looking arrangement. To make the modification seamless Tamarit hollowed out a channel in the tank which the seat pan sits within. Once again this is purely a visual modification and offers no kind of functional benefit, but it certainly adds to Sigma’s unique look.
For this build the performance modifications have been kept simple with a few tweaks for improved handling and performance. In the rear Tamarit has dispensed with the Bonnevilles’ notoriously sloppy suspension and replaced them with Hagon’s Nitro shock absorbers. To free up the flow of gases the factory air box has been removed and K&N filters fit to the intakes. Then to make the most of the power of the engine and give the bike a suitably aggressive bark, Tamarit fabricated a tracker-styled high-mount twin exhaust.
The removal of the airbox has also helped to balance out the mass of the Bonneville’s beefy new tyres. Handling improvements be dammed the Continental K112 rubber makes a bold statement, especially with matching width tyres on the front and rear. Bulking up the appearance of the rear end even further are lenticular wheel covers which were originally designed to improve aerodynamics. In this instance, it’s all about style and they’ve been finished using a similar paint scheme to the fuel tank.
“As is customary with many of Tamarits projects, Sigma features extensive use of chrome plating. In this project, a chrome plating process has been carried out on parts such as the seat posts, the shock absorber and the engine.” says Tamarit and there’s no shortage of shine on this T100. The paintwork uses a classic Triumph two-tone approach with gold pinstripes separating the green and cream. The finishing touch comes in the form of Tamarit’s own tank badges and numbered Sigma emblems on the frame.
The result of Tamarit’s work on this T100 is a motorcycle that defies categorisation. With elements of tracker styling and an air of Harley’s 48 Sportster, it’s not going to win everyone over. But as the name suggests, this Sigma marches to the beat of its own drum.