In 2009 the first Stromer was ready for the swiss roads. Rigid aluminium fork, narrow 26" tires and on behalf of the 360Wh battery 5 Bar pressure (to reduce the rolling resistance and improve the range). No doubt, riding at Stromer speed was shake, rattle and roll. On non-paved forest trails or on snow covered roads with frozen lane grooves was it impossible to exceed ridiculous speed.
The solution: FOX F100 / 32 RL at that time the best suspension fork for fast road bikes. The FOX changed everything, especially the geometry of the bike. Seating position raised, handlebar raised even more - and steering angle becomes more flat. With other words: The Stromer lost some agility.
The real different thing was the adjustment of the suspension. It should relieve my wrist - but not dive too much on regular braking. The rebound was left untouched.
The company was aware of this dilemma. The answer was the ST1 with flexible carbon fork and larger tires. The still weak motor (lack of torque) let the people raise the air pressure. This hindered the comfort somewhat.
In 2014, the ST2 appears. A milestone for the e-bike industry. With the same suspension concept as the ST1 but with stronger motor. Rolling resistance is no more topic. The riding comfort is similar to the Stromer with the FOX fork.
More difficult the situation with the ST2s. Tires little bit more narrow, air pressure high due to the sporty riding style. once again, this hindered the comfort somewhat.
Then the ST1x. With same tires as ST1 / ST2, but with rigid aluminium fork. This saves some money, as the ST1x is the new entrance model. I didn't ride engouht long long with it, but I would understand everybody who complaint about lack of comfort.
Soon, the ST5 will come. A completely different Stromer. Larger wheels, much bigger tires and rigid aluminium fork. Riding pressure allowed down to 1.9 Bar. All components together give a new suspension concept without reducing steering precision. Personally, I strongly recommend a long test ride to build your own opinion!