Yamaha YZF-R1

This post is my 2nd instalment in tracing the history of the most iconic motorcycle ever produced.
So read on & enjoy ..................

Has it really been thirteen years since the R1 first appeared? It was late summer, 1997, when we saw the first pictures of Yamaha's game changer. Back then, Honda's CBR900RR ruled the roost-nothing could come near its awesome combination of light weight and strong power output. Kawasaki had tried with its ZX-9R, and Yamaha had come up with the FZR1000R, but both of these were bloated heavyweight bruisers in comparison to the CBR.

So Yamaha did the obvious thing and built a bike that blew the Honda out of the water. A genuine 150 HP superbike in a tiny, sub-600cc chassis package, with "No Compromise" as its catchphrase. It instantly became a legend, and although some of the later versions have ended up a little flabby, it's earned a place in the SSB Hall of Fame. Here's the inside story on the tech and design behind this incredibly influential motorcycle.

Kunihiko Miwa, designer
of the original R1, explained
that it was createdwith
"no compromise" at its heart..

Kunihiko Miwa, designer of the original R1, explained that it was created with "no compromise" at its heart.

The Tech
The original R1 was a triumph of packaging. Putting a 150 HP engine into a chassis smaller than most 600s was groundbreaking stuff, but how did Yamaha do it? The motor was made more compact by moving the gearbox up and behind the cylinders. Previously, engine designers simply laid the crankshaft, gearbox input shaft and output shaft all in a line, making the engine long front-to-back. Yamaha relocated the gearbox shafts into a triangular arrangement, moving the crank and output shafts closer together. This made the engine shorter and allowed for a longer swingarm while retaining the desired short wheelbase. A longer swingarm improved stability, as did the R1's long-travel front forks. These gave more "sag" in the front suspension, keeping the front wheel on the road longer during hard acceleration.

Fueling on the first R1 was by 40mm Mikuni carbs, so the power delivery was super-smooth (especially compared with some of the fledgling fuel injection systems of the time), and Yamaha's EXUP valve further improved midrange. Although almost every bike has an ECU-controlled valve in the exhaust system now, back in 1998 it was still a novelty thanks to the firm's patents on the technology.

1998 R1

By 2002, fuel injection was becoming unavoidable due to emissions regs. The then-available systems needed careful design to provide good fueling, but Yamaha decided against using the same dual-valve throttle system used on Suzuki's GSX-R range. Suzuki's system used a computer-controlled secondary butterfly valve to match the actual airflow into the engine to what the engine can actually cope with. So when the rider slams the throttle open at low revs, the GSX-R opens the secondary valve more slowly, which prevents the airflow into the engine from "stalling."

Instead, Yamaha pioneered a novel CV-carb-type system. This used a suction piston similar to those on a CV (constant velocity) carburetor to control a throttle slide. When the rider opens the throttle the butterfly valve opens instantly, but the spring-loaded suction piston is opened more gradually by the engine's intake vacuum. As it opens, the airflow is more smoothly managed.

The R1 entered middle age and its chassis matured too. Japanese production engineering had developed new casting techniques that allowed lighter, smarter frame designs. Rather than just welding two extruded aluminum beams to swingarm and steering head pivot plates, these new cast frame components allowed the designer to make the frame very stiff in some areas but remain flexible in other places.

By 2009, most people agreed that the hard part of making a literbike was making the massive power outputs manageable. Yamaha decided to attack this problem in a couple of ways with the 2009 R1 update. First and most obvious, it fundamentally changed the architecture of the engine's bottom end. It swapped the conventional flat-plane crankshaft used in every inline-four cylinder engine to come from Japan for a new "cross-plane" design. Basically, this arranges the four crankpins at 90 degrees around the crank, rather than in two pairs 180 degrees apart. This means that the four cylinders fire in a different order, characterized as "big bang." The result is an engine that sounds more like a Ducati V-twin than an inline-four. The other change is, according to Yamaha, in the way that the engine's torque is transmitted. The firm claims that the cross-plane crank's irregular firing order transmits less "inertial torque," and this improves grip and drive.

Variable-length velocity stacks came around in 2007. Variable-length velocity stacks came around in 2007.		YCC-T electronic throttle bodies also were part of the 2007 update. YCC-T electronic throttle bodies also were part of the 2007 update.			2007's new motor moved to a four-valve head instead of the previous five-valver. 2007's new motor moved to a four-valve head instead of the previous five-valver.

The 2009 model introduced
the industry's first crossplane
crankshaft design.

The 2009 model introduced the industry's first crossplane crankshaft design.

But the other factor that improves the power delivery on the 2009 model is its engine management. The ride-by-wire throttle system gives better feel from the engine. Essentially, there is a non-linear relationship between the twistgrip and the throttle valves. Depending on the gear, revs and twistgrip opening, the ECU will sometimes give more (or less) throttle valve opening. The result is, for many riders, a smoother power delivery out of corners.

One downside of this new system is a lack of power and an increase in weight and size. The cross-plane crank is heavier and longer, and it needs a heavier, bigger engine to deal with the extra vibes. Indeed, a cynic might suggest that the R1's easier performance out of corners is simply down to having less power to tame in the first place.

TIMELINE

1998
Bang! That was the sound of the world motorcycle media's collective jaws hitting the deck when they first saw the new Yamaha YZF1000-R1. For the first time, the Japanese had come up with an open-class liter sportbike that wasn't just the size of a 600, it was the size of one of the tiny 400cc sportbikes sold in Japan. There was nothing tiny about the performance though: R1 designer, Kunihiko Miwa, used the catchphrase "No Compromise" during the design process, so the new bike had a full-bore 150 HP power output with excellent torque. That teensy chassis had some tricks up its sleeve: long-travel front forks to keep the front wheel on the ground for a fraction of a second longer under acceleration, in a bid to aid stability. We were used to Yamaha's excellent brakes by then, and seeing the familiar blue-anodized calipers assured us that the R1 would stop as well as it went. Finally, the new bike had super-sharp bodywork with fox-eye headlamps, a tidy tail unit and classy but aggressive red or blue paint schemes.

2000
Two years into its life, and the R1 was still miles ahead of the pack. Yamaha had made, apparently, more than 100 changes to the 2000 R1, but there was little obvious difference at first glance aside from the new titanium end can and sleeker bodywork. New engine mounts on the frame claimed to improve handling, and all the detail changes lost a bit of weight (about 5 pounds). Power remained the same though, and in 2001-its second model year-the R1 lost out to Suzuki's frankly awesome GSX-R1000.

2002
All the bike firms knew that upcoming emissions regulations would make carbs obsolete by 2005, so the switch to fuel injection was unavoidable. Yamaha plumped for a suction-piston type system, and while it worked well, it had the feel of a stopgap setup about it. The amount of effort needed to get EFI working well meant there were no other massive changes: detail mods cut a bit of weight, and peak power moved up the rev range a little.

2004
For the first time, the R1 began to look quite different. The side-mount silencer morphed into a pair of underseaters, the front brake calipers went to radial-mount items, and the fairing widened out a little at the front to accommodate a pair of gaping ram-air intakes. Inside the engine there was a big makeover too: the bore got bigger and stroke shorter, which allowed even more revs and even more peak power. Ram-air, fuel injection, short-stroke engine and lowered gearing all made for a faster, livelier performer.

2006
A mid-life tweak for the 2004 model gave us a few more HP, some minor handling updates and a fancy-pants Yamaha 50th Anniversary edition in yellow with Öhlins suspension, slipper clutch and Marchesini wheels.

2007
Surprisingly, just a year after a minor update, Yamaha brought out another massively updated model. It dropped its twenty-year-old 20-valve philosophy, and a new 16-valve head (supposedly using tech borrowed from the Rossi's Yamaha M1 MotoGP bike) appeared. The new head breathed through another innovation: the YCC-T, ride-by-wire fuel injection that made the transition from the 2006 R6. On the chassis front, the brakes were six-piston radial calipers and the rear shock got separate high and low-speed compression damping adjustments.

2009
Yet again, Yamaha went back to the drawing board for the 2009 redesign. The engine got a new cross-plane crank, the engine management got smarter with different power maps and the suspension got another tweak. Many riders loved the new "big-bang" engine's Ducati-like droning exhaust note and the ride-by-wire throttle's better power delivery. But for all that, the new bike was less powerful than before, heavier, and had a tendency to run uncomfortably hot. It did well in many magazine tests and managed to win the WSB championship in the hands of Ben Spies, but its long-term legacy remains to be seen.

Specs
1998-01
Engine: l/c, 20v, DOHC inline-four, 998cc, 11.8:1 compression, 4x40mm Mikuni CV carburetors
Power: 150 HP@10,000rpm
Torque: 70 lb-ft@8,500rpm
Chassis:Front: 41mm fully adjustable USD forks
Rear: fully adjustable monoshock
Brakes: Front: twin 298mm discs, four-piston Sumitomo calipers
Rear: 245mm disc, twin-piston caliper
Weight: 389 pounds (dry)

2002-03
Engine: l/c, 20v, DOHC inline-four, 998cc, 11.8:1 compression, 4x40mm CV-slide EFI throttle bodies
Power: 148 HP@10,500rpm
Torque: 72 lb-ft@8,500rpm
Chassis:Front: 41mm fully adjustable USD forks
Rear: fully adjustable monoshock
Brakes: Front: twin 298mm discs, four-piston Sumitomo calipers
Rear: 220mm disc, twin-piston caliper
Weight: 382 pounds (dry)

2004-06
Engine: l/c, 20v, DOHC inline-four, 998cc 12.4:1 compression, 4x45mm CV-slide EFI throttle bodies
Power: 152 HP@12,500rpm
Torque: 75 lb-ft@10,500rpm
Chassis:Front: 43mm fully adjustable USD forks
Rear: fully adjustable monoshock
Brakes: Front: twin 320mm discs, four-piston radial-mount Sumitomo calipers
Rear: 220mm disc, single-piston caliper
Weight: 378.4pounds (dry)

2007-08
Engine: l/c, 16v, DOHC inline-four, 998cc, 12.7:1 compression, 4x45mm fuel injection with YCC-T ride-by-wire
Power: 156 HP@12,500rpm
Torque: 77 lb-ft@10,000rpm
Chassis:Front: 43mm fully adjustable USD forks
Rear: fully adjustable monoshock, high/low-speed comp damping adjust
Brakes: Front: twin 310mm discs, six-piston radial-mount Sumitomo calipers
Rear: 220mm disc, single-piston caliper
Weight: 380 pounds (dry)

2009-10
Engine: l/c, 16v, DOHC inline-four, 998cc, 12.7:1 compression, 4x45mm fuel-injection with YCC-T ride-by-wire
Power: 147 HP@12,500rpm
Torque: 75 lb-ft@10,000rpm
Chassis: Front: 43mm fully adjustable USD forks
Rear: fully adjustable monoshock, high/low-speed comp damping adjust
Brakes: Front: twin 310mm discs, six-piston radial-mount Sumitomo calipers
Rear: 220mm disc, single-piston caliper Weight: 454 pounds (wet)

The 1998 is one of the baddest
bikes on the road to this day.

The 1998 is one of the baddest bikes on the road to this day.

What's the best model?
Hmm-tricky. The hype says go for the 2009-10 bike with its cross-plane crank and Ducati-esque exhaust note. But the truth is that bike is heavy, underpowered, and overpriced in the market. In a few years, the novelty of its weird exhaust noise will be over and you'll be left wondering why you paid all those extra greenbacks for something that's 50 pounds heavier and 15 HP shorter than your buddy's ZX-10R.

Look for a 2006 with the 50th
anniversary graphics to really
stand out from the herd.

Look for a 2006 with the 50th anniversary graphics to really stand out from the herd.

With that in mind, we'd make two suggestions. First choice is a nice, stock original 1998 bike. It still looks sharp after all those years, has ample HP for a load of fun, and is light and simple compared with later models. If you must have something fuel injected though, then the 2006 bike gets our vote. The underseat cans look sharp, there are radial calipers up front and the performance is stellar.

WHAT BREAKS?

On all models, the EXUP valve in the exhaust header pipes can seize up if it's not maintained properly-the heat and acidic exhaust gasses attack the pivot point. A sticking valve can snap the operating cables, and will cause poor running depending on where it seizes. On the transmission front, the clutch can be wrecked by too many ham-fisted wheelies, and hard use can also cause gearbox problems that will dent your wallet to fix. Head bearings and fork seals suffer from half-assed wheelies too, and because rear wheeled antics are part of the nature of this bike you can expect them to need replacement.