Opinions on R1

2004 Yamaha YZF-R1
Here Comes A Whole New 1!
By Peter Jones
Photos by Tom Riles

The 2004 Yamaha YZF-R1 isn’t just all new, it’s all different too. It has an all-new personality and an all-new feel. And a new sex appeal.

The news about the new R1’s engine is that it isn’t simply reworked and refined, it’s also reconfigured. The changes might seem subtle but have drastic consequences. For instance, the cylinders now lean forward at 40 degrees: ten more than all previous R1s. This results in improved engine efficiency, lowering of the bike’s center of gravity, and less use of the engine as a stressed member. This also allows the frame to pass over the engine rather than around it. Change begets change. The stacked transmission is now stacked with the alternator, contributing to the engine’s reduced width of a full two inches.

Interior changes to the engine are numerous. The new head has an additional water jacket, the already narrow valve angle has been tightened by a full degree and the valves on both sides are 5mm larger in diameter. And yup, there are still three intake and two exhaust valves per compression chamber. The now shorter valves ride on cam lobes with higher lift and longer duration on the intake side, less lift with more duration on the exhaust side, and the squish area was reshaped for a higher compression of 12.4:1, up from 11.8. A newly designed hydraulic cam chain tensioner keeps the cam chain in place.

The pistons are 3% lighter yet are now 77mm in diameter, up from 74mm, and sport shorter skirts. Short skirts are nice. Since it has a new bore it also has a new stroke, at 53.6mm. The shorter stroke contributes to the increased redline. The connecting rods are more rigid yet lighter and feature fracture-split big ends. This makes them mate perfectly and means that the caps individually mate only to their respective rods.

The crank is 16% lighter yet has bigger diameter journal and big-end pins. A fair deal of the lighter weight is due to the crank’s length being trimmed by an inch, the result of it carrying less on its ends and the pistons being located closer together. Yamaha stepped back from its move to one-piece cylinder-upper case to a separate, sleeveless cylinder with bores merely 5mm apart. Over boring the new R1 engine will pretty much result in a one-cylinder engine. And get this, redline has been bumped up an incredible 2,000 rpm to 13,700! Going there makes my bones feel like noodles, and my noodle feel like a… nevermind.

The transmission was tightened up by moving the shafts closer to each other and the shift fork shaft is now oil pressurized for improved durability and action. The clutch is lighter and narrower and the friction plates are now paper instead of cork with their number down one to eight. Spring tension is now taken care of by one coil spring rather than a diaphragm, as in the previous R1s.

The last version of the R1 had the world’s best EFI ever put on a four-cylinder bike. The trick behind its smooth performance was CV-like diaphragms controlling the air flow. No competing system offered anywhere near the lurch-free power delivery at all throttle positions. For 2004, Yamaha nixed the diaphragms for a system with a brain twice as smart, bigger bores, longer injectors, and servo-controlled secondary butterfly valves. On the exit side of the head is a four-one-two titanium exhaust system with Yamaha’s now regularly copied EXUP valve.

And finally the R1 has ram air. Yamaha claims that at high speeds the ram air boosts the horsepower to 180. At what speed exactly we weren’t told, as neither were we told from where exactly they took the hp measurement. But it’s a nice sounding number.

The 2004 R1’s chassis is more rigid, more compact and lighter. Or if you prefer, it’s less flexible, less big and less heavy. The spars are nearly three inches closer to each other, giving the rider a completely different closer-kneed riding position. The steering head webbing now serves double function as part of the ram air induction system. The rear subframe is a CF diecasting in one piece, allowing it too to be lighter and stronger.

The one mm shorter swingarm of the ’04 R1 is a two-piece CF casting with the bridging support running underneath it rather than over the top. This allows a more practical routing of the under-tail exhaust system.

The rear shock has a piggyback reservoir now mounted horizontally. Preload and damping are fully adjustable, albeit, the starting point of their rates has been refined. The front fork features 43mm Kayaba tubes with a whopping 25 and 26 positions of compression and rebound adjustment respectively.

Adding to the changes in the new R1’s feel is 5mm more offset of the fork, resulting in the trail being reduced from 103 to 97mm, give or take a millimeter. Yamaha added a steering damper to the new R1 that is hydraulically variable depending on the speed of fork oscillation.

Braking up front is taken care of by a pair of unusually large 320mm rotors pinched by radial-mount four-piston calipers. The master cylinder is also of a radial design, with adjustability for lever position. It also has a larger piston than last year. Contrary to intuition, a larger master-cylinder piston requires more braking effort and provides less feel. Maybe Yamaha decided the brakes were too good and wanted to reduce the chance of zealous operator braking indiscretions. The rear caliper meanwhile is lighter and a single-piston design.

The rims on each end of the R1 have five-spokes rather than three, yet each are lighter than the previous by 10% and 7.5%, front and rear. Other details include a lighter, smaller battery, a shift light, clock, fuel gage, diagnostic codes displayed on dash, and an LED taillight.

Since the R1’s frame is nearly 3 inches narrower, the fuel tank is 2 inches narrower at the knees. The clip-ons are 10mm higher and the rearsets are 2.5mm further forward and 7.5mm lower. The new seating position is more relaxing, more natural and more conducive to longer rides and taller riders. It’s comfy. It’s a friggin’ chopper!

Yamaha is quite aware of the importance of styling and even showed us research identifying that it’s the number-one consideration for purchasing a bike. They know this also because in ’98, when the R1 first appeared, it didn’t have performance numbers equal to the ZX-9, but it way outsold the competition. The new R1’s sex appeal is taken to the next level with its sharper nose, ram air intakes, and under-tail exhaust system. It still looks like an R1 but it also looks brand new.

Adding to the R1’s latest winning look is engine performance that will clearly run with the competition. Which reminds me, I love a shift light on a one-liter sportbike; if you see it even in first gear you’re breaking the law. It’s adjustable on the R1 so that’s not strictly true, but you get my point.

The acceleration of the new R1 is so much stronger than the previous version that it’s apparent without any comparison. This thing pulls so hard it forces the rider to pay close attention. When the throttle is held wide open there’s a lot happening and it’s happening quickly. Really quickly.

Although the new R1 has more serious power, the changes to the EFI make it lose a bit of the smoothness the old system had when going from full off to back on with the throttle. This is only noticeable when exciting tight turns on unknown roads but needs to be mentioned because it’s not lurch-free like the previous system. Nonetheless, it still does seem smoother than most other systems.

Together with the all-new feel of the power is an all-new feel in the R1’s handling. It no longer has that middleweight light touch that made the first R1 famous. Its handling feels now more like that of a Gixxer 1000. There are so many changes that could each contribute to this new feel: less trail, a steering damper, different forks and shock, a more tilted engine, stiffer frame, a one mm shorter swingarm, a one mm longer frame, an altered center of gravity… and so on. A motorcycle is more than the sum of its parts, it’s the result of its parts.

More power, heavier steering, more comfort, more sex. If you loved the past R1 there’s much to love here but also much that’s different, some for better, some not for better. It’s a lighter machine but it feels heavier while also storming forward faster.

Yamaha wants you to remember, unlike its competition, it has many performance parts available through its own accessories catalogue from GYT-R aftermarket exhaust systems to expensive kit racing parts. A pipe and competition air filter just might wake this thing up a bit. If that seems excessive to you, you don’t understand.

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