The Pionyr (or Pioneer) was introduced in 1955 as model 550, which became known as the “stump” because of the shape of the saddle.  This wasn’t classed as a moped but was a lightweight motorcycle and was designed by Jawa but made by the Povazske Strojarne factory in Western Slovakia, later to go on to produce the Babetta models.  See the two articles right, for more on the 550. In 1958 a new model, the 555 was introduced with a number of improvements, see the 1958 CMR article below-right for more details.
As some of these adverts show, the Pionyr was sold along side the Jawetta. The Pionyr, which didn’t have pedals, was marketed as a lightweight motorcycle.  The Jawetta, with pedals, was a moped being more suitable for “women and juveniles” - their words, not mine.  Although both had similar 49.8cc engines, the Pionyr had 2.2HP with a 3 speed gear box against the Jawetta’s 1.5HP & 2 speed box.

An article about the model 550 from Czech Motor Review 11/1956. 

From Czech Motor Review 8/1989 looking back at the history of the model.

From an East German newspaper “Berliner Illustrierte” dated January 1956.

The full story of my own 1957 Stump. 

A report on the model 550 “Stump” from a German issue of CMR 1/1956.

Details of the model 555 from Czech Motor Review

Two adverts from Finland, from 1960.

A 1959 letter to dealers from the UK importer.

A road test of the model 555 from a UK magazine

From Czech Motor Review 1/1958 introducing the 555 model.

Two versions of a similar 1959 Pionyr advert.

Some Pionyr photos from magazines.

A 1959 advert from the USA and another from the UK.

In 2006 a company called Motoscoot started producing a re-creation of the model 555. Here are a couple of posters and other information for the NEW Pionyr.

A technical article on the Pionyr from a 1959 CMR.

Some Czech magazine covers.