Yamaha Tdm 850
YAMAHA TDM 850
CYCLE WORLD TEST
Coming soon to a dealer near you. Maybe.
CREATING A RADICAL NEW MOTORCYCLE LIKE the Yamaha TDM850 demands courage, the kind of bravado that costs millions of dollars in design efforts, carefully monitored surveys and extensive advertising campaigns. And there's never any guarantee of success.
Through the years, Yamaha has developed hosts of new designs, some featuring off-center styling cues. Confused customers have shied away from such examples. like the power-cruiser Fazer 700 and the single-cylinder SR600, both good bikes, but not successful in the showroom.
\\cll. \amalia is at it a~Lin. \k"hile I londa, Ka~vasaki and Suzuki have spent the current year introducing retrostandards like the Nighthawk 7~O. the Zephyr 7~() and the ( iS.\ I I UO( ; , Ya maha has twisted the standard theme in to a completely new configuration. Ihe II)M8.~() is Yamaha's concept of' the standard motorcycle for the `90s and hevond.
I )esigned as a versatile, do-everything motorcycle, the `II )\1 may, nonetheless, leave some enthusiasts questioning the hike's intended purpose. Is it a sporthike. a Paris-toI )akar replica or something in hetween? I'he tall appearamice and upright handlehar suggest a d ual-purpose image. vet the wheels are shod with wide, street-only ruhher. A glance helow the fIghter-plane half'-Iairing reveals the engine, a Iwin, hut one that has as nianv advanced features as a modern Four. And, even more hewildering. the massive l'rame spars look like they would he more at home on \\avne Rainev's (iP hike.
As wonderful, or confusing. as the `it)M may appear. one thing is certain: It is currently unavailable in the t Jnited States. The II)N1 has been introduced in Europe and (`anada onk. but according to Yamaha public-rela tions man John ( ale, interest in hrin~zin~ it to the U.S. as a I 99~ model is strong. "Since the I'I)M is already in pro duction. that is possible. suggests (lale. Our prediction is that Yamaha will indeed oiler the l'l)\l for sale here next \ ear.
Rut vhat marketing niche is Yamaha attempting to fIll with the 50 Twin?
"We're not trying to build a new market with this hike.'' comments (lale. "In Europe. the I l)\1 is called New Sports: it's intended to be the King of the Road. Yes, the TI)N1 does have a Paris-to-Dakar look, and delivers many of the sensations of a dual-purpose bike. but without any of the compromises.''
(iale further explains that the l'l)M can he thought of as a cross between a dual-purpose hike and a sporthike. ``An XT3SO, for example. is easy to ride at slower speeds. say up to 50 mph. then it begins to be a compromise. On the other hand, an FZR1000 excels at higher speeds, where the X 1350 doesn't. But the FZR doesn't negotiate parking lots as easily. The TDM is the best of both worlds, with a dual-purpose riding position matched to a rigid Deltabox chassis and a performance-oriented Genesis engine.”
Based heavily on the engine that powers Yamaha’s Super Fernere 750, a mammoth, Paris-to-Dakar replica never offered in the States, the TDM's parallel-Twin has been punched out to 849cc. accomplished by increasing bore and stroke measurements to 89.5mm x 67.5mm. Following the Genesis design, first introduced on the FZ750 inline-Four. the engine is liquid-cooled and features five valves per cylinder. As with the Ténéré's motor, the TDM's is tuned for torque and uses short-duration, narrow-overlap camshafts and a relatively low, 9.2:1 compression ratio.
To minimize vibration, a pair of gear-driven counterbalancers are placed fore and aft ol' the 360-degree crankshaft. Promoting a short, compact design, the crank and transmission shafts are staggered and dry-sump lubrication is used; the oil tank is located below the seat. To provide a straight route to the combustion chambers for the twin, 38mm Mikuni downdraft carburetors, the entire cylinder bank is tilted forward at a 45-degree angle, which also lowers the engine's center of gravity.
A tug on the choke knob, located below the left frame rail, and a quick stab on the starter button brings the engine to life. Even when cold, the engine tires immediately and the choke can be thumbed off' promptly. Midrange torque is good, but not spectacular, especially in roll-on comparisons, sav. to last month's test Ducati 900SS. Carburetion is responsive throughout the entire rev range, although an abrupt off-idle response is bothersome. Also, the engine doesn't enjoy being lugged below 2000 rpm.
Even with the twin counterbalancers, engine vibration is noticeable, but only problematic between 4000 and 5000 rpm. Cruising in top gear at 3600 rpm delivers a smooth 70 mph, but once the tach needle crests 4000 rpm. vibration seeps through the pegs and. most noticeably, the rubber-mounted handlebar. As the revs continue to climb, the vibration dissipates, but never completely disappears. Like the rest of the bike, the TDM's engine is a good allarounder. It’s fast, but not blisteringly so, barely dipping into the 1 1 -second bracket at the dragstrip. It is easy to use, though, with a linear, unintimidating powerband. But as well as the engine performs, its exhaust note is anemic at best. The engine idles almost inaudibly, and even while spinning in the upper reaches of its powerband, it never delivers any real aural pleasure.
Pleasure does await the TDM rider on twisty backroads, where he can stick the bike in one gear, usually fourth or fifth depending on the layout of the road, and wail away. This flexibility is important because the five-speed gearbox provided a few problems. Besides being clunky, especially on downshifts, the selector would occasionally jump out of gear. Although the shifting improved over time, a smooth downshift demanded blipping the throttle to freely operate the shift mechanism.
Rather than a single-backbone frame as used on the Super Ténéré, a steel Deltabox chassis was chosen for the TDM. As on the FZRs, the engine serves as a stressed member, increasing rigidity. The combination of a stiff frame and the leverage provided by the wide handlebar means that initiating a turn is direct and immediate. But the TDM is intended to be more than a backroad blitzer, and its suspension, tuned more for all-around use than for locked-wrist cornering, bears that out.
A stout, 4lmm cartridge fork provides 6.3 inches of travel and offers a very plush feel, perfect for soaking up everything from freeway expansion joints to backroad potholes. Beyond the soft initial movement, the fork is more progressive, but doesn’t have the tautness that dedicated canyon chargers will want. Both preload and rebound adjustments are available; we left the preload alone and kept rebound damping in the first one-third, or stiffest range, of the 18 available settings.
At the rear is Yamaha’s Monocross system mated to a steel, box-section swingarm. The shock absorber is mounted directly to the arm —there's no linkage set-up— and features a two-step, variable-rate spring adjustment. Instead of a single spring, two are used, the lower of which is the stiffer of the two. A spacer separates the springs. With the adjuster set in the Hard position, only the stiffer of the two springs is used. Moved to the second, or Soft, position, both springs are utilized. The idea is that the rider can alter the shock’s spring rate for either solo or two-up riding, or for different riding conditions, with one simple change. A small range of preload adjustment is also available, via a threaded preload collar at the bottom of the shock.
Small, sharp-edged bumps transmit jolts directly through the rear suspension, which is, unfortunately, not as compliant as the fork. But, otherwise, the rear suspension does a decent job. Travel is 5.5 inches and, like the fork, rebound damping is adjustable. Thirty-six clicks are offered, but, realistically, less than half of those are usable. The first dozen clicks from full stiff'provide a good range of adjustment for a variety of riding styles.
A trio of disc brakes haul the TDM down from speed. Up front, a pair of 1 1.7-inch floating rotors are gripped by opposed, four-piston calipers. The front brakes are strong and will easily lift the rear wheel, but their strength highlights the fork’s soft initial travel. At the rear, a single 9.6inch disc and twin-piston caliper are used.
Bias-ply Bridgestone Exedra tires are mounted on threespoke alloy wheels. The tires are capable enough, but don't provide the glue-like traction of premium rubber; really hard riding has the tires sliding. A stickier choice would allow the rider to take full advantage of the TDM’s excellent cornering clearance.
Unlike the current crop of hard-edged race-replicas, the TDM offers rational ergonomics to match its sporting engine and chassis technology. The upright seating position is complemented by the tubular steel handlebar, fftted with Yamaha's usual, well-thought-out assortment of levers and switchgear. The handlebar bend provides enough forward lean for the rider to be supported by the incoming airstream, much of which is deflected by the nicely shaped fairing and windscreen. An upswept lip at the top of the screen improves wind flow over the pilot's head and minimizes buffeting, even for taller riders.
The two-tone, stepped seat is uniquely shaped, with its front edges wrapping around the fuel tank. Cut deeply to lower seat height, it allows even short riders to place both feet firmly on the pavement. Unfortunately, the seat's padding is too soft. Less than 50 miles in the saddle left both pilot and passenger squirming. The rubber-covered footpegs are located with comfort in mind, yet are high enough to allow good cornering clearance.
Visually and functionally, the TDM850 is a drastic change from the norm: This defintely is not a run-of-themill retro-standard. But underneath that avant-garde bodywork waits a wonderful motorcycle, technically advanced, yet comfortable to ride and, at approximately $6500. reasonably priced. It truly is as versatile as any streetbike now on the market, and more so than most. Perfect it's not, but as other manufacturers offer standardstyle motorcycles that draw from the past, Yamaha, with the \ DM, has looked ahead and come up with a fresh, exciting design. Whether or not this new concept will be a hit on U.S. soil is a question that waits to be answered.
As Yamaha knows only too well, there are no guarantees to greatness in the new-bike business. E3
YAMAHA
TDM850
$6500
EDITORS' NOTES
REMEMBER THE THREE WITCHES IN Shakespeare's Macbeth? For hours, they stirred their special brew and concocted wicked poems. A weird group of senior citizens, for certain. 1 liken Yamaha’s design engineers to those old witches. I can just see these guys stirring their alphabet soup while coming up with twisted ideas for new bikes. This month alone, we've seen the TDM. a bug-eyed streetbike in dirtbike costume, the futuristic Apex 750 concept bike, the Zeal 250 and-be still my beating heart-the TZR250. And don’t forget about the rumored RADD design and the Morpho showbike from last year. What will Yamaha come up with next?
What it's come up with in the TDM is an excellent allaround package, one that’ll make you believe in the company’s particular brand of sorcery. The current crop of old-style standard bikes doesn’t really light my lire, but the TDM does. Here’s hoping we see it soon. —Matthew Miles, Associate Editor
“THAT CAN’T BE BE RIGHT: 507 POUNDS with a full tank of fuel?” I thought to myself. “That’s heavier than a 600cc Four.” I’d ridden the Yamaha TDM850 prior to its weigh-in, and while flip-flopping through a stretch of backroad twisties, I would've sworn the bike didn’t weigh an ounce over 400 pounds.
Well, the certified CWscales don’t lie. So, perhaps my senses have been dulled by too many miles aboard moreconventional sportbikes, their steering made heavy by stubby clip-on bars and fat tires.
The TTTM’s engine is impressive in light of the bike’s weight. Fairly smooth-running—except for the buzz band between 4000 and 5000 rpm—the TDM's Genesisderived motor seems more like a Multi than a Twin.
Yamaha may have something with this versatile, funto-ride streetbike. I just wonder how much more enjoyable it would be if Yamaha’s engineers could put the TDM850 on a diet to lose those extra 100 pounds. —Don Canet, Associate Editor
MY SLANT ON THE TDM850? 1rs A pared-down Paris-Dakar-style bike intended for street use only. After a decade of popularity in Europe, P-D replicas are beginning to wane, but their bump-soaking suspension and comfortable riding position are still welcome, especially on the Continent, where very few riders actually take bikes off-road, anyway.
This Post-Dakar bike is a pretty nifty piece, too. I’d like more seat padding and gummier tires, and if the bike were mine. I’d drop-kick its exhaust plumbing as far as I could (not very, considering its weight). In stock form, whatever noise limps past the various pre-mufflers and baffles is as flat and watered-down as ballpark beer.
As noted, this bike makes sense in Europe. It makes sense over here, too. But given our usual reception to bikes that stray off the beaten path styling-wise, whether the TDM makes friends over here is a different question altogether. —David Edwards, Editor
