The three-stage race, which also occupies a new slot on the calendar, will comprise a feature event over a total of 200km as well as a Lite version of 170km.
Race director Patric Mosterd, of Garden Route Events, said by shortening the two races they were able to cut out portions that did not necessarily add value to any of them.
"By doing this, we are left with only the good stuff as we pursue a truly pure mountain biking experience."
Mosterd said the GR300, as it is known these days, would still remain a genuine test.
"Just because it comprises fewer kilometres, does not mean it is any less of a challenge," he said.
"Basically it is a case of fewer kilos but more quality and I can assure you that the riders will be pleased to see the finish line each day."
He said the more compact stages do however shorten time spent in the saddle, making it more accessible to participants who would have been on the edge of their ability previously.
The idea, he said, was that the shorter days would be an additional incentive for prospective participants to try out the Garden Route event for the first time.
"We really want to share this gem of a riding area with as many people as possible."
With the event initially taking place at the height of summer as a precursor to races like the Cape Epic, Mosterd said there was a feeling that the original distances were just too far for its current slot - especially being in a mountainous area.
"We think the event is now doable for a broader spectrum of riders instead of just a select few. We hope many more can now enjoy the experience with us."
He said the stage distances of the feature event would be 75km, 50km and 75km.
Mosterd said the Lite version, which was introduced three years ago as an alternative to the main race, would also have a facelift.
"The first and third stages have been shortened by approximately 15km each as we want to give riders with less mountain biking expertise a chance to catch the vibe and spirit of the occasion."
He said it also offered an easier access path into the event for relative novices, who would then be able to upgrade to the feature event in following participations.
"We live in a tourist town, which is a holiday destination for many families. We want to create a situation that appeals to everyone."
He said they operated the GR300 as "one event", with everyone starting together.
"But what happens is that the Lite cuts out the more technical parts and one or two long climbs before re-joining the feature race.
"This means family and friends can start together and possibly finish together without all the riders having to do the toughest sections of the course."
Mosterd said the distances would be 60km, 50km and 60km with entries being open until the week of the event.
"However, there is a cut-off (April 10) for the registration item, which is an outer garment from apparel company Capestorm."
Caption: The Garden Route 300 will offer a purer mountain biking experience when the three-day event takes place in Knysna from April 28 to 30. Photo: Julie Ann Photography