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?

3. Penton 125 Mud Lark

worst dirtbikes
Penton 125 Mud Lark

John Penton is deserving of every accolade he has received in his career, but the Mud Lark is a blemish he’d probably rather forget. In 1973, Penton was selling some great race and enduro bikes that were being produced by KTM in Austria. However, he was forced to buy a whole load of the Sachs 125B engines in order to get a supply of the “good” engines. So, to get rid of the B engines, Penton contracted with Wassel, an English fabricator, and they threw together a frame, a set of wretched Betor forks, ginky shocks and a layout that made you feel like you were sitting on the edge of a pinball machine.

John called it the Penton Trials, but not even Batman could have ridden it in a trials event. There was no power at all, the gearbox was spaced oddly, and the bike wouldn’t turn without plowing the front end. So, in desperation, John renamed it the Mud Lark, a sort of all-purpose play machine. In fact, it was a no-purchase dirtbike, and will go down in history as one of the few bad business decisions ever made by savvy dirtbike innovator John Penton.