2010 Beta Evo 250 4T | Review

Observed trials has had a tumultuous relationship with four-strokes since Sammy Miller's Bultaco won the 1965 Scottish Six Days Trial, breaking a 30-year stranglehold on the sport by four-strokes.
In the aftermath, Honda was the primary torchbearer for thumping trials bikes, occasionally winning world championships against two-strokes, which remained the standard bearer for the local riders.
The James Dabill-piloted, Honda-powered, high-tech fuel-injected Montesa Cota 4RT brought four-strokes back to the Scottish winner's circle in 2007 after a drought of more than 30 years.
And while Honda (via Montesa) has dominated modern-era four-stroke observed trials, that hasn't stopped French Scorpa (Yamaha-powered, now bankrupt), Spanish Sherco and Italian Beta from offering their own thumper alternatives.