SUZUKI TM400 CYCLONE - The most dangerous bike ever built?

THE MOST DANGEROUS DIRT BIKE EVER BUILT?

Nov. 01, 2005 By ORC STAFF

EXAMINING THE LEGEND

Riding a Suzuki TM-400? Then it never hurts to bring your own flowers. Faithful dog is bringing a stick to use as a splint, just in case.

In 1971, with a great deal of fanfare and hoopla, Suzuki introduced the TM-400 Cyclone motocross bike.hoopla! The press affair was held on a Warner Studios lot and Captain Kirk himself was the celebrity who worked the microphone for the starry-eyed media.

William Shatner stood up there, without a Star Trek uniform, I must sadly report, and told the gathered faithful about the brand new line of bikes from Suzuki. Being a Star Trek fan at the time, I believed just about everything he said. After all, wasn't this the man who kicked Klingon butt?

After a seemingly endless line of street and dual-purpose bikes, the "secret" new MX bike was rolled out by a pair of pneumatic blonde models. We all oooohed and aaaahed at the awesome-looking motorcycle. The damned thing had a truly impressive appearance, with incredible detailing. It was orange in color, with a flat-black finned motor and a sinuous expansion chamber that snaked around the chassis.

I simply HAD TO SIT ON THE BIKE and see what it felt like. Everything was right where it should be, and I clicked the throttle open and closed enough times to satisfy some weird primeval urge.Wow!If looks would determine a winner, Suzuki would have been handed the trophy on the spot.

The specs on the TM-400 Cyclone (cool name!) made your mouth water if you were a dirt bike nut:

Five speed box

230 pounds weight

40 horsepower at 6,000 rpm

P.E.I. Electronic ignition

Oil injection (no more mixing oil and gas!)

Nice long telescopic forks up front

Shocks that appeared serious at the rear end

Real aggressive knobbys wrapped around aluminum rims

Slim, trim feel through the mid-section

Big modern Mikuni carb

Brakes that worked

REALITY CHECKS

Since Suzuki had been kicking butt on the World MX scene with Roger DeCoster and Joel Robert on the exotic RH Suzuki works bikes, we expected that the TM-400 would have a lot of that technology built in.

Captain Kirk assured us that the TM-400 was the closest thing to a factory works bike that money could buy, and was a machine for "Experts" only.Since the bar was now open and the journalists were swilling, we all believed him.

It was a fewmonths before I got my chance to test one of the new Cyclones. Suzuki made sure, naturally, that the "friendly" magazines got the bike first, to be assured of good tests that could be used in ads.

The Cyclone fired on the second kick, and snarled to life with an ear-crackling sound puffing from its open expansion chamber.Yup, back in 1971, racing bikes were sold without mufflers of any sort.For sure, at least 40 screaming horses were inside that impressive flat-black motor, and the sound from the stinger let you know.

My first trip through the gears was across a flat, smooth area, and at this point, I was convinced this was the finest race bike ever built.The power ripped!While there wasn't much torque down low, the engine hit brutally hard at mid-range and then literally jumped to peak revs.

It was hitting a light switch, rather than rolling on a throttle.

Appropriate number on the plate; was the Cyclone the most dangerous dirt bike of all time? Read on and find out.

By the time I had put in two laps on the motocross track, I knew something was dreadfully wrong with either me, or the Suzuki. Whenever I tried to accelerate smoothly out of a bumpy corner, that staggering mid-range would hit and the rear end of the bike would lurch outward. On the short smooth straights, the Cyclone was all you could want, as it pulled hard and clean, and would slow down with authority, as the brakes were far superior to the typical European stuff that I rode at the time.

After 20 minutes of riding, I was drenched in sweat and my hands and forearms were horribly cramped. The bike had scared me badly. Was it me? "Hey, who wants to ride this thing?"

The testers ? all expert level riders ? fought over who got the saddle next.Al Wurtzel, a very fast desert racer, won the coin toss and went out on the course.Ten minutes later, he came in, shaking. "This thing is dangerous! Here, somebody else give it a try."

By the end of the afternoon, all of the test riders, from Novice (me) to Pro, agreed that the all-new, technology-inspired Suzuki TM-400 Cyclone was the worst pile that had ever come out of Japan. If you rode it cautiously, a 125 could beat you around the track. If you rode it aggressively, chances are you would get spit off.

When the TM-400 hit a bump while under power, there was no telling what it would do.Those spiffy forks were as bad as everything else from Japan at that time, and the shocks were beyond grim. Later, when we put the shocks on a shock dyno, we found out that the damping curve was 50/50 (compression/rebound), about the same as your family car.

The frame geometry was flawed, and there was a huge amount of flex both in the frame and the swingarm. When riders tried to turn the Cyclone quickly, the front end would either push badly, or the bike would try to stand up when power was applied.

Plenty of power was on tap with the TM. Check out the serious rooster tale as it attacks a 1975 brother bike.

Amazingly, the bike sold well and you started seeing the orange beasts showing up on MX and desert tracks around the country. People believed all the ads, the bike did look great, and the price was right. Under a thousand bucks for all the power you could ever want.

And very soon after that, the word started getting out: this bike was hurting people!Riders were getting pitched off in corners like so many off-balance frisbees. All those bright orange paint jobs started getting chewed up from slithering and lurid slides, with and without riders aboard.Suzuki owners were limping around, or worse, sporting plaster.

A small industry quickly developed trying to make the bike work.The reasoning was that the bike was so good, there was so much stuff there, that it just had to be some little quirks to be worked out. They put Koni shocks on the rear end and that helped some.Forks were diddled with, but the smart guys gave up with the KYBs and opted for proven Spanish forks.

Frame kits blossomed up all over the place, some simple and some so complex they defied belief. Heavy flywheels were bolted to "smooth out the power" and that also helped some. But the bike remained hard to ride and kept biting riders.Eventually, complete frames were offered, that housed the fierce motor in a chassis with proven geometry.

I was doing my own experimenting with the TM-400 at that time, and stumbled over the real reason the bike was such a brute to ride.The P.E.I. system was the real culprit. It was designed to have the ignition retard for easy starting, and to advance at a certain rpm range for maximum performance.

Somewhere around 4000 rpm, the electronic ignition would go from a mild retard mode, to FULL ADVANCE, with no graduation at all. Bang! The proverbial light switch. What made this problem even more pronounced, was that the "jump" never happened at the same rpm twice in a row. When it was cold, it might hit earlier.As the engine warmed up, it might jump 200 or 300 rpm later. But you could never predict exactly when.

White knuckles were the norm on the "?" bike from 1971 through 1974.The 1975 model alongside was not that bad of a bike, but by then, the reputation sealed its fate.

The cure for the crazy power band was so simple that it made people want to bang their heads against a wall: simply replace the modern high-tech P.E.I. system with an old-style points/mag setup. The unit from a TS-400 "enduro" model was a bolt-on cure.

Suzuki never corrected the problem until 1975. Oh, sure, they painted it yellow and gave it Bold New Graphics each year, but the heart of the beast remained intact. The 1975 bike wasn't all that bad, but people weren't buying it anymore. Memories are hard to forget.

It took a completely new bike, the RM that appeared in 1976, to erase those memories.

But for those who still limp from their days with the TM-400 Cyclone, well, they wince whenever they see one of those orange beasts from the past.

4 Comments

Daryl Aug. 27 2011
In 1973 i lived in washington state and everyone in our neighborhood started getting dirt bikes. by 74 ten of us had bikes and would congregate at the dirt pits about 3 miles from home. as we got to be better riders our bikes got better. i personally went from a suzuki 90 to a 125 then a 185. a friend talked his parents into buying him a brand new bultaco pursang, a 250 i think it was. my friend weighed all of 140 lbs soaking wet and dident have what it took to kick start that bad boy but he lived on a hill so starting it initially wasent a problem. he became "the man" when he showed up at the pits with his new bultaco because nobody could even come close to keeping up with him. all that changed one day when i heard about a guy that had a 73 tm 400 cyclone for sale that was within my price range. it needed a chain and both sprockets if i remember right. i showed up at the pits and several friends were there including "dan" and his pursang and for the next hour i smoked his bultaco! this was one of the best days of my life up to that point! there was one hill that nobody had been able to climb yet and dan and i both wanted to be the first to scale it so we both bolted for it at the same time. it was about 80 ft from the bottom to the top and had a road cut into it about halfway up that ran left to right,..like a plateau. i was ahead of dans pursang when we started up so all i had to go on was onlookers that said he jumped the plateau and spun to a stop about 10 ft later. my 400 jumped the plateau and bogged a bit for 20 ft or so and then,..well i had to rely on the same onlookers to tell me what happened next. apparently along with all the above mentioned "quirks" this bike had,..it had a problem with the throttle sticking in full twist because when the new cheng-shin grabbed a good bite it launched itself 30 feet past the top of the hill with me attatched to it like a big blue dog tick! the top of the hill was the top of the pits and it was just a huge flat field. i dont remember much between the first plateau and the nurse at tacoma general hospital. i broke my right shoulder, right wrist and two fingers on that hand, left ankle and a hairline fracture in my left leg. the bike was bent up pretty bad too and i think i ended up selling the engine to a guy that put it on a go-cart. i think from the time i bought it to the time it broke me was 3 whole days and about 8 miles. to this day my shoulder will start throbbing 30 minutes before it starts raining.
MAICO MC 501 Feb. 21 2013
THE MOST DANGEROUS? THATS AN UNDER STATEMENT! I SAW FIRST HAND WHAT THIS FRANKENSTEIN OF ALL DIRT BIKES COULD DO! THIS BIKE WAS NO SUNDAY DRIVER! ONLY ONE BIKE COULD COME AFTER THIS BIKE THE MAICO MC 501! MOST PEOPLE OPTED OUT ON THE STOCK THROTTLE AND PUT ON A MAGURA FAST THROTTLE. DIALED IN THESE BIKES WERE EXTREMELY EFFECTIVE AND QUITE DEADLY!! TO SEE ONE OF THESE ON THE DIRT TRACKS WAS BAD ENOUGH TO COME UP AGAINST ONE WAS EXTREME STUPIDITY! ONE OF THE BEST BIKES EVER BUILT!! THEY GOT IT RIGHT DECOSTER WAS AWESOME ON THIS MONSTER!!
Matt Apr. 5 2013
Hey great story Daryl, don't everwant to ride one of those. I still have the RM370 from 1976 , glad they got the bugs out of the animal. sorry you got so banged up on that climb.at least you cleared the top.lol you know the saying no gut s no glory, well I'd say you had the guts so theres your glory man !
ATKIN May. 27 2013
TM 400 i had one. Japanese answer to the MAICO MC 501 ! I broke my knee cap on that bike and tibia. I hope i never see either bike again! Extremely powerful and both bikes were deadly on the race tracks! TM 400 Cyclone was no toy this was a factory racer as were all the Maico's. Another nightmare from hell was the Honda 250 Elsinore Silver tank
green striping! Stay the hell away from that bike! I watched that go after a TM 400 cyclone and Maico radial fin i believe it was a 490 Magnum ! THat dont make bikes like this any more all liquid cooled garbage!
Back in the 70's i used a JOFFA MOUTH GUARD with the plastic dental guard you put in your mouth came with plastic strap for the mouth guard! I miss the 70's ! Bikes back then were deadley, dangerous, loud expansioned chambered the fuck out! The sound from these bikes music to my ears! Easey Rider ?? Opening scene ha ha!!

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