Rick Sieman’s 10 Worst DirtBikes in History

Rick “Super Hunky” Sieman calls out 10 of the worst dirtbikes ever. Most of their owners wish these slugs had never left the factory. Do you own one?

1. 1971 Suzuki TM400 Cyclone

worst dirtbikes
Suzuki TM400

If you come across any list of the worst dirtbikes in history and the Suzuki TM400 isn’t number one, it’s either a phony list or it was compiled by Suzuki!

Cyclone indeed. It weighed 242 pounds, dry, and delivered about 40 horsepower at 6850 rpm… But sometimes it delivered it at 4400 rpm. At other times, it would deliver it just when you least expected it. You see, the Cyclone had a weird ignition that would go from a starting mode to full advance whenever it felt like it. Even a change in temperature would change the power hit.

Picture this: you’re exiting a hard- packed turn in second gear and you roll the throttle on. All of a sudden, the engine lurches into the fat part of the power curve and the rear end leaps out about three feet. The chassis shudders and sends you sailing into the clear blue sky in a nice arc. Moments later, you thump into the ground, painfully, and then a microsecond after that, the Cyclone lands on top of you.

Adding to the bizarre powerband was a set of forks that went rigid on square bumps and rear shocks that faded from anything hotter than headlight glare. Many companies produced endless handling and frame modification kits. None of these things seemed to help much, but the bike cost only $995 brand new and people kept buying them, trying to make them work. They all failed, to one degree or another, to tame the Cyclone. Even Suzuki factory riders like the late, great Rich Thorwaldson would cut the frames to lower the engine in the chassis, swap the TM ignition for the external rotor design used in the more sedate TS400 enduro and covertly slip Ceriani guts into the fork tubes!

The legacy of the TM-400 can be summed up in an ad that appeared in a newspaper: “For sale-1972 Suzuki TM-400. Only 10 hours on bike. Possible injury forces sale. $500 or best offer.”

That guy actually made it 10 hours on a Cyclone before crashing himself into oblivion? Someone call the AMA Hall of Fame.