Who doesn't have memories of daring Lego constructions that eventually broke due to their own weight and the builder's lack of knowledge of statics? Jens Fischer had similar problems to solve when he built a one-to-one scale replica of the racing bike he occasionally takes for a spin out of Lego bricks: "The wheels were far too fragile. They kept crashing," he explained to the German portal rennrad-news.de.
It all started quite professionally. Jens Fischer is an accomplished Lego builder who designs his constructions on the computer before he starts putting bricks together. There are programs that allow you to design a building block by block on the screen - similar to CAD in architecture. Every existing Lego brick can be called up and used in any color. Fischer spent the first 100 hours creating the Lego racing bike on the computer.

Collapsing wheels

However, the program only simulates the geometric shape. It does not calculate whether the construction will hold, i.e. whether it can withstand its own weight. The result was the collapsing wheels, along with other minor construction problems. Among Lego builders, it is frowned upon to glue parts together or to stabilize a construction with additional elements such as wire. But the full-size wheels left Fischer no choice, so much support was needed. He estimates the weight of his Lego bike at 12 to 15 kilos. "You can't weigh it either, because the assembly stand is currently holding all the weight," he told rennrad-news.de.
After all, the hobby cyclist has not only succeeded in recreating his bike in such a way that it can only be distinguished from the original at second glance. Fischer designed the drivetrain so that the chain actually moves the rear wheel - if the bike doesn't fall apart again straight away. According to Fischer, even the rear derailleur and front derailleur can be moved. "But you can't sit on the saddle," he admitted to Rennradmagazin, "because then it breaks down."