2001 Triumph Bonneville - World Exclusive!

Ten Years After Its Rebirth, The New Triumph Resurrects The Old Triumph's Most Revered And Significant Motorcycle-And Invites A Magazine Editor Me! To Be Part Of The Development Process

By Mitch Boehm, Photography by Kevin Wing, Kyoichi Nakamura

Roughly three years ago I approached Triumph America CEO Mike Vaughan with an idea I'd been considering for years: to write an in-depth feature story on the start-to-finish development of an all-new motorcycle. I reminded Vaughan I'd been through the R&D process with several new models during my years with American Honda, and that those experiences would help me communicate to readers at least part of the complex-yet-fascinating story of an all-new motorcycle's tortured path from concept stage to actual production.

Vaughan liked the idea (a good start), and said he'd pass my proposal on to Triumph Motorcycles Ltd. owner John Bloor (even better). Still, I had no illusions about it being accepted. I'd already pitched this particular idea to several other manufacturers, none of whom were interested (or brave) enough to actually take me up on it. Motorcycle manufacturers are notoriously secretive (for good reason), and don't like to even think about having outsiders in their midst.

So imagine my surprise when Bloor, Vaughan and U.K. export boss Ross Clifford agreed in early '98 to play along. They told me the company had recently embarked on an all-new, clean-sheet design, and that they were willing to let me get involved in the bike's actual development-and then write about it. But the motorcycle they wanted to let me watch take shape over the next 30 months wasn't some slightly reworked Daytona or semi-new, modular-based Speed Triple or Thunderbird; they were offering me the inside line on the new-generation Bonneville, arguably the most important machine in the new Triumph's 10-year history, and maybe even the entire 2001 model year. And a motorcycle named after one of the most revered and successful bikes the motorcycling world has ever known.

Initial shock turned to excitement pretty quickly.

As magazine editors and bike testers we get handed the keys to new motorcycles all the time, but rarely are we privy to the development process that takes place two to three years prior to a bike's official debut. While some manufacturers provide peeks behind the development curtain through the use of early concept sketches and clay mockup photos, these are only snapshots of the R&D cycle, and don't-can't, really-give journalists (and readers) much of a feel for the development process.

My goal was to give readers that feel, to provide that look inside the R&D tent. Helping me tell the Bonneville story would be Motorcyclist contributor Alan Cathcart, a guy who's seen the inside of more R&D centers than I could mention. Cathcart became a partner in this story fairly early in the Bonneville's development, and not only added significant meat to this piece, but also helped Triumph engineers tweak the Bonnie in several positive ways with his substantial evaluative skills.

This isn't the "complete" development story on the Bonneville (it'd take an entire book to treat the subject comprehensively), but it should offer readers an idea of the phenomenal amount of work, sweat, insight, expertise, testing, cash and chutzpah it takes to bring an all-new motorcycle to market.

April, 1997
Starting From Scratch

Triumph's product-planning group didn't originally set out to simply "build a new-generation Bonneville," as many will likely assume when the Bonnie makes its world debut this September at Munich's Intermot show (and its U.S. debut at California's Del Mar Fairgrounds on October 7-8). The team's initial goal when the 908MD project officially launched in early 1997 was more open-ended: To develop an "entry-level machine of medium to large displacement"-somewhere between 700cc and 800cc. The "entry-level" component of that formula is significant because, as things stand for the 2000 model year, only two bikes in Triumph's line-the Adventurer and Legend TT-could be considered even close to true "entry-level" products, and they're really too large (physically and displacement-wise) for that niche. With the United States and world markets changing so dramatically, and with hordes of new and re-entry riders joining the motorcycling ranks, it was considered vital that Triumph have a competitive player in that category.

In fact, the decision to head in a classic-styling/vertical-twin direction-the Bonneville direction-came only after Triumph product-planners researched and considered a range of styling and engine treatments, primarily custom-styled, V-twin-powered bikes, which account for a staggering 90 percent of the midrange twin market. So what pulled Triumph toward the classic Bonneville direction in the face of such powerful V-twin market numbers? "Triumph's heritage," says Clifford. "Though a V-twin was the obvious option," he told me, "we decided to develop a parallel engine layout due to the 'heritage' aspect."

Of course, "heritage" can be a touchy subject where Triumph is concerned, especially among Brit-bike traditionalists, some of whom consider the "new" company to be as "Triumph" as Honda is, say, Harley-Davidson. Clifford and Vaughan understand the sometimes tricky ground they tread when they use the word. Still, they do use it, and rightly so. After all, Meriden "memories" and thousands of vintage Triumphs are all the motorcycling world would have if Bloor hadn't secured the Triumph name in '83, spent the better part of seven years figuring out the level of technology and investment it would take to compete in the modern motorcycle market, and launched a brand-new bike manufacturer in 1990-one that now produces more than 24,000 motorcycles annually (from three per day in 1990 to more than 125 per day nowadays in an all-new and very high-tech factory).

It's not the old Triumph, but it's Triumph all the same.

Once the decision was made to go with a vertical-twin engine, the development team was fairly certain of the styling direction it needed to follow, though dealer and internal company research was done to test the team's gut feelings. Clifford says the feedback was both instant and unanimous. "With a vertical engine in the mix," he told me, "the styling of the machine simply had to be 'Classic Bonneville.' " The decision-making process used to arrive at this point was typical Triumph-and smart: Do what will work best for the lineup, not what might be historically warm-'n'-fuzzy. The fact that the two usually differing paths ended up sharing common ground is likely to be significant for classic bike fans worldwide.

But the question begs-and it's one I asked Clifford during one of my U.K. trips: Why not build the Bonnie earlier? "If we'd done the Bonneville when we first launched the company," he told me, "we'd have likely been pigeonholed as a manufacturer that could only copy things. Doing a twin was so...expected. But more importantly, we needed to build a solid base for Triumph, and that meant developing an entire lineup of bikes, which our modular concept (three-cylinder 900s and four-cylinder 1200s) helped us establish. Building a twin in those initial years would have restricted our model range. Also, we first needed to develop a dealer network, and in several countries. This base would set the stage for our nonmodular projects, the TT600 and now the Bonneville."

Triumph was off and running.

July, 1997
The Engine Team Comes Together

It's difficult to overestimate the amount of time, planning, investment and engineering work it takes to design, test and put into production an all-new engine. There's initial design, computer modeling, prototyping, tooling design, production and testing, power/durability/homologation testing, numerous suppliers to deal with, etc. The costs alone are staggering; I've heard the $10 million number mentioned on occasion, though the actual amount surely varies depending on the type and complexity of the powerplant in question. Still, it's a huge undertaking, and it helps explain Triumph's early focus on the highly efficient modular-engine concept-and why it waited nearly a decade before building nonmodular engines.

The Bonneville engine team had a tough task: marry modern technology (and power and durability, etc.) with classic engine architecture. It wasn't only a difficult assignment, but the success of which was absolutely vital to the project's success. A fragile and/or underwhelming engine could sink the Bonnie just as quickly as an aesthetic treatment that fell short of the mark. And that's a mark etched way, way down the field. This was a Bonneville, remember, a bike considered by many to be the classic Brit-bike. The T120 Bonnie is regarded as a fast, decent-handling and absolutely beautiful machine; it's a reputation that was a constant challenge to the Bonneville team throughout the entire R&D process.

With the team assembled and the engine's most basic parameters-an air/oil-cooled parallel-twin of between 700cc and 800cc of displacement-agreed upon, work began in earnest. Early on, Triumph contracted with engine design and development consultants Ricardo to develop via computer some basic engine specifications (ideal bore and stroke, power and torque curves, etc.). The data would help team members work out the most basic engine-design parameters, allow them to build early prototype parts and begin to look at how to best package the engine itself.

August, 1997
3-D Styling Work Started

Like the engine team, Bonneville stylists and chassis team members had the tricky job of blessing the new Bonnie with thoroughly modern function and a look as close to the original Bonneville's as possible-not easy given the massive gains in chassis development over the last several decades. So they started from ground zero, purchasing a fully restored, 1969-spec T120 Bonnie at great cost, re-importing it to the U.K. from the States, and using it as a baseline for items such as styling, ergonomics, control positioning, etc. "The '69 bike embodies the best possible attributes of the [old] Bonneville," Clifford told me. "We felt it was the right place to start."

With the restored T120 safely ensconced at Hinckley, a whole range of measuring and computer modeling work began. For instance, to get a proportional view of the way a modern engine would look mated to original Bonnie styling and geometry, engineers took a right-side profile photo of the T120 and stripped in an image of an early new-Bonnie engine (from the engine team's early computer-modeling work) in place of the old motor. The result was encouraging. As the basic layout of the new bike took shape on the computer screen (clay modeling wasn't used by Bonneville stylists), a variety of elements began to fall into place, including frame design (with Finite Element analysis ensuring it would be strong enough), desired ergonomics, control positions and chassis geometry. From these chassis parameters, engine team members could begin to nail down the basics and positioning of key engine details, such as output shaft position, engine center of mass and overall size.

British designer John Mockett, who'd worked with Triumph closely over the years, was then tapped to piece together a 3-D styling model to see how the early computer images worked in the flesh. A rough model of the proposed frame was used, along with a wood mockup of the proposed engine, various handmade body parts, and basic suspension and wheel components. While Mockett worked the styling model in late 1997 and into early 1998, the engine team pressed on, working toward the scheduled first run of a prototype Bonnie engine at the end of 1998.

June, 1998
A Visit To The Factory

I made my first trip to the U.K. for the Bonneville project in the summer of 1998, sitting down with Vaughan and Clifford as they brought me up to speed on the bike's progress. We looked at sketches, at Mockett's styling prototype, and discussed various elements of the project such as the type of power delivery Triumph wanted and such items as steering characteristics and suspension/ride qualities. Although the project was only little more than a year old, Clifford had already compiled a folder full of notes. In fact, Clifford acted as my eyes and ears while I was in Los Angeles, keeping me up to date on the bike's progress. He was a major help.

Summer and Fall, 1998
Styling Reviews, More Testing

Mockett's styling prototype was hugely important because it showed Triumph engineers and stylists how successfully (or not) their computer-aided designs translated to metal, plastic and rubber. Some, of course, didn't translate well. The initial frame design, for instance, was deemed aesthetically unfit for the look they wanted, and was scrapped for a slightly different cradle-style unit that was both stronger and more aesthetically pleasing. Shortly thereafter the Mockett prototype was shown to a slightly wider audience, who agreed on several changes already being considered by the styling team. These included changing the mufflers to the original "peashooter" design (a tricky packaging job), tapering the barrels to give the engine more of an "original Bonnie" shape, tucking the headers in slightly more, giving the front fender T120-like struts, redesigning the seat with a less-pronounced step, and revising the instruments. These changes gave the new Bonnie the basic look it'd have right through to production.

Toward the end of 1998 chassis testing heated up. Using a Euro-spec twin-cylinder bike from a competitor as a donor bike (a shortcut that significantly cut development time), engineers cut and re-welded its frame to mimic the exact geometry they'd decided on, then added the pegs, wheels, suspension, swingarm and handlebar they proposed for the Bonneville to replicate the rest of its (eventual) chassis setup. A key design brief was that the machine had to be "light, agile, and corner well." Rigorous testing showed the desired geometry to be spot-on; the bike was stable and secure at speed (much more so than the T120 they tested alongside it), yet still offered reasonably quick steering. (Although significant to the new Bonneville's story, the chopped donor bike was apparently very, very ugly. Clifford's resistance to my repeated requests to see or photograph it is probably quite telling as to just how homely it really was!)

Things heated up on the production side also. The chassis and engine teams were already at work compiling what are called "engineering lists," which detail the exact parts needed for the building of prototypes and, eventually, actual assembly-line production. From these and their blueprints would come "bills of labor," which assist the team in the costing and production of every single part of the motorcycle. My mind went numb when Clifford lead me through this process; I remember marveling at the complexity and cost of it all-and the huge potential for screw-ups.

December, 1998
Engine And Chassis Teams Rev Up

The engine team-now seven engineers strong-was moving especially quickly, and due to more than simply the projected December 1 date for initial engine start-up. Like the TT600, the Bonnie would use high-pressure die-cast crankcases, which are more consistent in terms of surface finish and quality than the sand-cast cases used on previous Triumphs. Problem is, HPDC cases are horrifically expensive to produce (a single die-casting tool costs about a million bucks), and have a lead time of well over a year. So it was vital the engine team get its engine testing done (using CAD program models to simulate dynamic testing) and finalize the crankcase design so the production of HPDC tooling could begin.

At this point, the design of nearly every component had been settled on, and prototype parts were arriving throughout the fall and early winter. The carbureted, air/oil-cooled vertical-twin would displace 790cc and use a centrally located cam chain to spin its double overhead camshafts (via a Suzuki TL-type hybrid cam drive for compactness), which in turn would move a pair of intake and exhaust valves per cylinder. Dual balancers were used as the engine was designed as a stressed frame member, and the transmission came straight from the company's six-speed triples, though with fifth gear blanked off, making the Bonnie a five-speeder with an "overdrive" cog. "We fit a lot of modern engine into a fairly compact space," Clifford told me. "It was a packaging nightmare; we'd wanted a dipstick but had to use a sightglass as there was simply no room for it!"

The first Bonnie engine ran on December 15, 1998, with little more than a few carb-jetting hiccups. The team-all of Triumph, really-was stoked. Initial engine testing then began, the teams first running the original prototype engine then others through all manner of timed-running and teardown/check phases. There were a few glitches, though nothing surprising. Endurance testing came next: The engines were run hard for extended periods of time, then torn down to check for wear and/or failures. The main changes made before committing to HPDC tooling production were minor: the countershaft sprocket was moved 3mm inboard (to help with peashooter-exhaust packaging), and the crankcase clamping design was altered for improved sealing.

By the end of '98, the engine was beginning to produce the type and amount of power the team envisioned from the start. Various combinations of camshafts and cylinder-head porting and compression were tried over the latter months of '98, the team settling on a combo that would offer as rideable and usable an engine package as possible.

Also by the end of 1998, the chassis team had presented the updated styling prototype (with the changes from the earlier presentations) to upper management and the marketing/ sales staffs, and response was positive. Small tweaks were made, though the bike was now much more "right" aesthetically. Scheming and detailing of the frame structure were now 90 percent complete, which allowed prototype blueprints to be made. Chassis testing (with a donor engine installed) and FE analysis showed the new frame to have even more torsional and lateral rigidity than a standard CB500 Honda twin, itself an agile, stable and competent handler, and a bike that would be somewhat of a Bonneville competitor in Europe.

March to September, 1999 Engine Meets ChassisIn March, 1999 a prototype Bonneville engine was installed in the latest chassis setup, and testing continued. Evaluators then began to focus attention on more detail-oriented aspects of the bike, such as carburetion, vibration control, suspension action, steering, etc. The entire package began to feel more capable and refined as they went. By July, six development bikes had been built, each one undergoing a specific testing regimen. As the evaluations progressed, and the specific teams got closer to finalizing the specs for final production-intent tooling, a final styling review was held, with even better results.

The overall look and general makeup of Triumph's new-generation Bonneville was now set.

October, 1999
A First Ride

I met Alan Cathcart at Triumph headquarters on the morning of October 7 for what each of us considered a truly momentous occasion: our first ride on the new-generation Bonneville. We met with Clifford and Vaughan and caught up on the goings-on since my last visit, each of us looking out the meeting room window and hoping the rain would stop before our evaluation ride later that morning. It didn't-though no surprise there!

The bike itself was typical of running prototypes: flat black in color, external wires leading to data-collection boxes, and looking not much different than a beat-up twin-cylinder courier bike that'd spent years combing London's wet and narrow streets-unless you looked closely, of course. Three other bikes would accompany us that morning: one of Triumph's own Legend TTs, an 883 Sportster and an example of Kawasaki's then-new W650 twin, a bike the Bonnie would be competing more or less directly with when it debuted.

Cathcart had laid out a superb test route for us, one full of winding, medium-speed country lanes, some around-town stuff, and a bit of freeway thrown in for higher-speed evaluation. Despite the cold and soggy weather the ride was good fun and highly informative, and after a stop at a pub for lunch, we made our way back to Hinckley for a debriefing with the R&D folks.

The Bonnie prototype was surprisingly good functionally, especially since it was powered by an early prototype engine and still a full year from production. The engine's power level was acceptable, though it delivered the brunt of that power too high in the rev-band. Cathcart agreed, and while he explained I could see the engine team leader slowly nodding as he took notes, almost as if he already knew the motor's midrange could-and should-be fattened a bit. (He did.) The rest of my comments mirrored Cathcart's, though they were nearly nitpicky; the seat foam was both too thin and too soft, letting my butt sink right onto the seat base; the front brake was only marginally acceptable, lacking both adequate power and feel (though it would improve, the team told me, when the bike's production-spec master cylinder was installed); and both ends of the suspension, I felt, could be firmed up just a touch, maybe 10 percent, for the older (and larger) riders that would surely form a significant portion of Bonneville buyers. Cathcart felt the suspension was about right, both compliant and controlled, but then again he's lighter than I am. Either way, the Bonnie's legs were pretty good as-tested.

I finished up with these words on the evaluation form: "Wet weather kept us slow, but overall, pretty impressive. Needs midrange, firmer seat foam, a bit more front-brake power and maybe slightly firmer F&R suspension. Styling seems right." Cathcart added this: "Warren Beatty would have been happy to be seen riding this in a reissue of Shampoo!" Well said!

June, 2000
A Second Ride

Cathcart and I returned roughly eight months later for a second evaluation ride, and more meetings with Clifford and the project leaders. "Things have progressed nicely," Clifford said over coffee that morning, reiterating what he'd written me via e-mail. When we walked toward the R&D skunk works later on with riding gear in hand, I could see what he meant; the prototype Bonneville sitting in the lot surrounded by production Thunderbirds and Daytonas now looked like an honest-to-goodness production motorcycle, its shiny, production-color paint, chromework and production-spec componentry giving it a highly finished appearance. We'd certainly have more trouble keeping this one away from curious or prying eyes!

Our test route that day was similar to the one Cathcart had laid out months earlier (though it was sunny and warm this time around). And it was obvious from the first few miles that the items we'd noted in our first ride had indeed been addressed. The engine's newfound midrange was noticeable right off, the bike now easier to ride (especially at slower speeds) with peak torque occurring at 3500 rpm rather than 5000 revs as on the earlier prototype (the changes resulting from intake-system and cam revisions). The seat was firmer and more comfortable as a result, and just as we'd been told months earlier, the production-spec master cylinder made a major difference in braking, giving the Bonnie's front disc plenty of power and progressive lever feel (the rear brake remained superb). Suspension settings were as-before, and they seemed plenty compliant and controlled for the bike's all-around m.o.

When the four of us gathered later that afternoon for a debriefing, I had but one critical comment (which says a lot about how good the bike was at that point). It centered on the bike's final-drive gearing, which I felt was a bit too tall and gave the bike a semi-sluggish feel when opening the throttle at both lower and higher revs. Although the Bonneville was more powerful than the W650 we had on hand for this second ride (claimed horsepower for the Bonnie is 62 hp), the bike just didn't jump ahead with the authority I felt it needed. Slightly shorter gearing, I felt, would help.

Clifford e-mailed me a week after I'd returned to L.A. with the following message: "I fed back your comments on gearing to the team. Prior to your second test we'd made the gearing taller to lower engine speeds while cruising by around 500 rpm. After hearing your comments we've reverted back to the original [shorter] gearing to bring back a bit more snap in the acceleration. The engineers were none-too-pleased. But in the end it was agreed to be worthwhile." This was good news (and maybe a little flattering), but somewhat frustrating, too, as I wouldn't be able to sample the benefits until our Bonneville test bike arrives sometime this winter. Still, I'm betting the added oomph is plenty noticeable.

July to October, 2000 The Road To ProductionFrom that test ride in June, team members continued revising and refining each component and system, doing any additional performance-, mileage- or homologation-testing that remained, the bike inching closer and closer to the time when actual production could begin. Team members checked off an ever-growing list of parts ready for a final prototype fitment check to see if they could be given the go-ahead for their actual production.

As production-spec parts arrived and were OK'd by team members, they were installed on an all-production-spec machine in a special room in the factory. When we dropped by the room on my final visit in June, the Bonnie sitting there wasn't too far from completion, with only a few major parts still missing.

"Looks pretty good, eh?" Clifford asked with a grin.

"It looks great," I said, shaking my head, not quite comprehending that what I was looking at was about to become a mass-produced, thoroughly modern, all-new motorcycle for world distribution. It was almost surreal; I'd seen this bike back when it was nothing more than a rough styling mockup; ridden it when it was flat black and courier-bike rough; felt the functional improvements later on-and now it was nearly ready for its coming-out party. Excuse me a bit of melodrama here, but it was nearly like watching one's kid leave for college-or board the elementary school bus for the first time.

I think Triumph's new-generation Bonneville will find success when it hits U.S. showrooms this December. I might be wrong; it's quite possible my closeness to the project is skewing my judgment here. But I don't think so. It's not an exact replica of the T120, and that could hurt it with traditionalists. But after having ridden it and experienced its functional goodness, and having watched the effort, brainpower and funds invested in its development, I somehow can't see it failing.

If it does, it won't be for lack of trying.

Bonnie Basics
Similar Yet Different: The Nuts And Bolts Of Hinckley's New-Generation Bonneville
As an eight-valve, parallel-twin with double overhead camshafts, the new Bonneville's powerplant is thoroughly modern, though it does share with its pushrod, two-valve-per-cylinder T120 ancestor a 360-degree crankshaft throw, with both pistons rising and falling together in the nickel/silicon-plated cylinder bores. That's a prime recipe for intrusive vibration, which may once have been considered desirable but nowadays is a customer no-no. Triumph's engine team therefore decided to incorporate twin gear-driven balance shafts located at 2 o'clock and 10 o'clock relative to the plain-bearing crankshaft.

The new Bonnie engine also needed to share the T120's power characteristics. The 790cc motor was designed to be "lazy" rather than "potent," which the reasonably long-stroke bore and stroke numbers of 86 x 68mm help ensure. Ditto the T120 engine's look, something designer John Mockett had a role in alongside the engine team. Although the new Bonnie's drive chain was designed to run on the right side of the bike (the T120 runs its chain on the left), several details were designed to keep the basic look somewhat intact, including the finned cylinder and dummy pushrod tube in front of the engine (originally intended to be an oil feed but now acting as a cylinder head oil breather). Although a wet-sump design with no separate oil tank (unlike the original dry-sump Bonnie), the new Bonneville engine employs internal oil lines wherever possible to retain a clean appearance, while twin oil pumps and a sizable oil radiator are fitted for cooling as well as keeping the plain-bearing engine's internals together.

Another ploy in helping endow the new motor with period looks is the Bonneville's TL1000-like cam drive system, with the centrally mounted chain driven directly off the crank to a set of idler gears in order to narrow the camshaft spread. Combined with dropping the cams in the heads to get the pushrod look, this reduces the engine height significantly.

Certain period Triumph traits were deemed surplus to requirements, however, hence the new engine's horizontally split crankcases designed to eliminate the oil stains in the owner's driveway invariably provided by its pushrod ancestor's vertically split engine. So, no comeback for those tarmac restorers of dubious chemical provenance so popular in mid-'60s California.

OK, but why go to all the trouble of having to dress up a DOHC 8-valve design to look right, rather than concoct a more humble, and presumably less-costly, single-cam two-valver?

"Two reasons," says Triumph's Ross Clifford. "One was that we're used to building engines with four valves per cylinder. Another was performance; 55-60 hp was our design target, and we wouldn't have got that power with two-valve heads. We did take a serious look at a six-valve engine with three valves per cylinder (two inlet, one exhaust). The cost effectiveness of going to three valves was marginal, so we opted for four." Running 9.2:1 compression, the design target was achieved early on, and in production guise the Bonneville delivers 62 hp at 7400 rpm, with maximum torque of 42 foot-pounds as low as 3500 rpm.

Since it was always intended that the Triumph twin-cylinder family for which the company intends a long production life would comprise only two distinct models-the Bonneville, and another new bike that will appear in due course-there were fewer design constraints on the new engine, with modularity not such a key issue as on other Hinckley Triumphs. But while it was always intended that the company's new twins should be stand-alone products, there was interest in parts commonality with the company's existing three-cylinder products. Thus, some components from both the older T300 and newer T500 models were used, such as the much-improved T500 six-speed gearbox-well proven on more powerful bikes such as the 955i, and here used on the Bonneville in five-speed guise-mated to a cable-operated wet clutch.

Unlike other recent Triumphs, the new Bonnie is not fuel-injected, but uses a pair of 36mm Keihin carbs fitted with electric heaters to combat icing, and a throttle-position sensor linked to the digital ignition to optimize throttle response. Triumph chose carbs rather than EFI mainly because of the style of motorcycle the Bonneville represents; it's not a sportbike. Cost was also a factor.

Triumph says it can meet all current emissions requirements with carbs, especially when air-injection is used. A catalyst exhaust has also been developed, but will only be fitted in those markets where it's required. The period-looking peashooter-type twin exhausts are uncharacteristically long in order to gain the requisite silencing capacity without compromising cornering clearance-the kink in the pipes helps pull them out of harm's way.

With the engine such a key component of the born-again Bonnie in styling as well as mechanical terms, the chassis team had to plan far ahead since, for the first time on any Triumph, the Bonneville's steel swingarm pivots in the engine crankcases as well as through steel chassis forgings in the interests of rigidity. The T120 was swiftly rejected as a design benchmark (apparently it was quite alarming how unstable test riders could persuade it to get at high speeds), while other candidates like the 90-mph 883 Sportster simply weren't fast enough. Triumph had a 115-mph target for the born-again Bonnie, which they say the new bike amply fulfills in production guise, and has been proved in testing to be stable in turns at that speed, even with a passenger. The engine is solidly mounted in the frame at five spots, with counterbalancers removing the need for rubber mounts. In fact, Triumph engineers have dialed some vibration back in by altering the bar weights to restore a little "character." The cylinder head is braced to the headstock to add extra stiffness, and twin front downtubes-compared with the old T120's single chassis downtube-pick up the engine at the front.

In keeping with the marriage of opposite design goals, twin Kayaba rear shocks adjustable only for preload are fitted in a semi-laydown position that Triumph says represents a compromise between the retro-upright look of the T120 and its ilk, and the modern slanted position of a twin-shocker like the CB500 Honda. These are matched to a non-adjustable 41mm telescopic Kayaba fork, set at a kicked-out 29-degree head angle, with 117mm of trail. Connecting them is a spine frame redolent of the early range of bikes from the Hinckley era.

"Stability was key, as well as the retro look, and the company has a good reputation for building solid-handling bikes," says Clifford. "We wanted our new-generation owners to experience the satisfaction of light steering with secure handling, hence the spine frame." This employs a 19-inch front wheel and 17-inch rear-the bigger front primarily to get the look right with modern lower-aspect 19-inch front tires, Triumph says. Bridgestone tires are fitted, the front a 100/90R19 and the rear a 130/80R17. The long, 58.8-inch (1493mm) wheelbase and relatively low 30.5-inch seat height-an inch lower than the original T120-emphasize the lean appearance of a 452-pound motorcycle on which shorter riders (and women) should feel at home, and which will be offered only with a sidestand (though with an optional centerstand), and with a flat handlebar fitted as standard. Unlike the old days there'll be no high-rise option for North American customers. A single front and rear disc, each gripped by two-piston Nissin calipers, are fitted; Triumph says it decided not to fit a second front disc for both styling and cost reasons. Equally, a rear drum was never an option: "We benchmarked the smaller W650 Kawasaki in terms of stopping power, which we've achieved, and for our target rider the rear brake is important," says Clifford. "That's another reason why there's no provision for a kickstart-our projected customer base looks for convenience over period quirkiness. This is a modern motorcycle in period dress, with all the attributes which this entails."

That it is. And after waiting patiently for a decade while John Bloor and his men brought Triumph back from the dead and secured the company's future, traditional enthusiasts now have the long-awaited opportunity to welcome back one of motorcycle history's best-loved models, in vastly improved guise-all for a projected sum of about $7000 in the USA, where 30-40 percent of the total production of 4000-5000 is likely to be headed.-Alan Cathcart

Riding The Bonneville
A Preproduction Bike, But A Functional Success All The Same
The first thing you notice when you hop aboard the new Bonneville is its excellent riding position. The old clich about "controls falling readily to hand" was never more true; the handlebar's shape and positioning offers comfort and control all at once. The entire cockpit, in fact, feels right. The same goes for the drone coming from the twin exhausts once you've thumbed the starter; Triumph has recaptured The Sound just as it was, but not the vibes that came with it. The Bonnie tingles just enough through the bars and pegs to remind you what it is you're aboard, but doesn't become tiring to ride even during longer stints, before you stop for coffee and reflect how much fun you're having.

The Bonneville's easy pickup off the mark and crisp throttle response belie the fact it only has carbs fitted, not fuel-injection. The easy power delivery and flat torque curve make this a relaxing ride that can also be invigorating if you want to push things a bit harder. You get spirited acceleration from low rpm, with a fat midrange that will have most owners shifting at around 5000- 6000 rpm. The gearbox shifts impeccably, and the closed-up bottom four gears with a gap to fifth complement the way you'll want to ride the Bonnie. Clutch action is light and progressive, which keeps one's hand from cramping while riding around town.

The bike's lean stance (and wide bar) make it easy to steer along twisting country roads-its natural habitat-in spite of the kicked-out front-end geometry and longish wheelbase. As you'd expect it's also quite stable 'round faster sweepers and at higher speeds, in keeping with Triumph's claims. The non-adjustable fork is reasonably compliant, and the twin-shock rear end irons out bumps better than expected, though rebound damping could still be improved; it bounces back a touch too eagerly if you hit a dip in the road. The brakes are now excellent, with lots of bite as well as feel from the single front disc, which is single-finger stuff thanks to an astute choice of master cylinder. The rear is easy to use and feels plenty responsive.

Every time I rode the new-generation Bonneville there was a notable improvement in the experience, a sense of added refinement and reduced compromise. Bloor's boys got it right, I think.-A.C.

Sixties Icon
Ah, the Bonnie, Triumph's fabled T120/R. For most of the volatile 1960s in America, this Triumph-lean of line, pure of function, fast and good-handling-was not only the archetypal sporting road bike, but something much bigger. The Bonnie's impact extended beyond motorcycling. It became a cultural icon, a symbol of a certain kind of life; like the Jeep, Fender's Stratocaster guitar, blue jeans from Levi Strauss.

U.S. Triumph dealers had been pleading for a high-power, twin-carb 650, and when it appeared in 1959, it was named for the Utah site of speed-record runs. Indeed, Triumph had held the absolute Land Speed Record for motorcycles since 1956 (214 mph with a 650-engined streamliner built in Fort Worth, Texas), and for years to come, the company advertised the T120/R as "the fastest standard motorcycle made in the world today."

The Bonneville's engine grew out of the 500cc Speed Twin created by Edward Turner in the late '30s. In high-output 650 form, it was leaning against its design limitations, but it worked, on both the street and the track. It vibrated, but they all did. The vertically split crankcase halves had standing oil above the seam (and often below it). It was all orthodox Brit-bike practice of the day: separate intake and exhaust cams down in the cases operating pushrods and rockers, a chain-driven four-speed gearbox and the general bits-and-pieces approach to component design. But the Bonneville worked the concept to a high polish.

Even 30 years later, it still looks great. You can see the sporting theme expressed in the compact but smooth-flowing tank (with the trademark paint scallops that actually originated at a Detroit custom-paint shop), the chrome headlight shell on fork ears, the narrow fenders, graceful pipes and general lack of frills. No wonder it was the lust object of its era.

The tale would turn ugly for Triumph and the entire British industry in the '70s. But until then, the Triumph Bonneville owned its age, and so became a motorcycle for all the ages. -Kevin Smith

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