On Friday, March 9, 2018 at 6:04:09 AM UTC-8, wrote:
Maybe I'm wrong, but while I applaud the ingenuity and craftmanship, I think any external bike rack on the sides of the trailer would be road-illegal in Europe due to considerations regarding the safety of pedestrians, cyclists and animals in the unlucky case of a collision. Such racks would certainly aggravate the consequences for the victims.

All the best,
Aldo Cernezzi
www.voloavela.it

Could be, guess you guys use smaller tow vehicles. In the USA, tow vehicles are typically wider than the trailer. Even with mountain bikes, which have wider handlebars, the bikes don't extend past the sides of the tow vehicles I use.

Most US states allow a vehicle width of 102 inches (259 centimeters).