The search for a new bike is almost always a lengthy process: the details you have to think about are too complex before the choice is narrowed down to a few candidates. One of the first and most important questions is the type of bike - and therefore the frame shape. The frame shape is crucial for comfortable, everyday use. If you have a child seat or basket on your bike, it is difficult to swing your right leg over the saddle when climbing or descending. Older cyclists are happy to have low step-through heights, as this makes it safer to get on the bike. Many female cyclists don't want to do without being able to cycle in a skirt or dress. This is simply not possible with a classic diamond frame, so only a step-through or ladies' frame is an option. The fact that both are less laterally stiff is therefore not an exclusion criterion.
DIAMOND FRAME
The traditional "men's frame" consists of several triangular constructions joined together - the optimum way to build a load-bearing, low-torsion chassis from a tubular composite. If you want to be light and stable at the same time, this frame variant is the way to go. Ideal for fast riding, but also for touring and travelling bikes with luggage transport. Depending on the material, tube diameter and shape, there are also major differences in the lateral stiffness of diamond frames. Rule of thumb: The more voluminous the tubes and the greater their support width at the tube nodes, the more stable a diamond frame will be.
TRAPE FRAME
If the top tube of a diamond frame is lowered at the seat tube, the result is a trapezoidal frame. This shape has many variations and allows you to get on and off the bike with an elegant foot lift in front of the saddle. The ladies' frame can therefore be ridden well with a skirt or dress, but also with a basket on the back. Disadvantage: low lateral stiffness due to increased torsion between the seat tube and head tube. This can impair riding safety when transporting luggage or with a child seat. It always depends on the tube quality and design, but with the same models, the women's frame is always less laterally stiff than the diamond frame due to the design.
DEEP RISER
Since the motor and battery have been integrated more and more fully into the design of e-bikes, aluminium box modules are increasingly being used in frame construction: angular profiles, large diameters, thick walls - thanks to the motor, weight does not play a major role. This means that such robustly built step-through e-bikes can often easily keep up with the structurally more stable diamond frame in terms of rigidity and riding safety. Or even surpass it occasionally. For non-motorised bikes, however, tubular construction prevails for weight reasons. For this reason, step-through bikes in this category are only recommended to a limited extent: moderate, well-maintained riding speed and no payload of more than around six kilos is advisable.
