Diamond frame

The developed around 1885 diamond frame is the most common frame shape in bicycles, particularly when Mr. wheels. The diamond frame has proven throughout the history of the bicycle as an effective form, even though there were numerous alternatives. The basic shape of the diamond frame was created after 1888 with the advent of low safety wheels and pneumatic tires in Europe, these wheels were originally referred to as " Rover ", such bikes on Polish still hot.

Description

Was named the diamond frame according to its shape. Top tube, down tube, seat stays and chain stays form the diamond frame approximately one pound, the short head tube remains exempt. The diamond is reminiscent of the crystal shape of a diamond. In English, diamond means next to " Diamond " and "hash". - But not always - the head tube and seat tube extending generally parallel.

Frame sizes

The frame height is usually measured from center of bottom bracket to top of saddle sleeve. In the framework of the Italian manufacturer de Rosa the specified level, however, are 15 mm added to, as these frames are measured differently. The optimal size of the frame depends on the leg length, approximately, it may be sufficient but, instead, to consider the body size. The usual hundred years ago, the bicycle design size using the wheels (26 or 28 inches) says today nothing about the size of the bicycle. A low frame with 28er tires results in a much smaller bike than a big frame with 26er tires. The dimensions given in the table below are Näherungwerte that relate to typical frame geometry with horizontal top tube, for wheels with sloping top tubes do not the measurements.

As women with the same body size often have longer legs, they're usually better off with a larger frame. Cheap framework of American manufacturers will gladly given in clothing sizes (S, M, L, XL). Due to the coarse grading less different frame sizes, which reduces the production costs arising.

Alternatives

For ladies wheels gooseneck frames are often used, while the wheel has either a more oversized down tube or two down tubes, the bottom bracket, these are curved. Female Frame with two straight down tubes are mainly used for sport bikes. A special form is the Pedersen, which has a higher seating comfort with less mass and higher stability. On newer mountain bikes, especially those with a suspension system, and Bonanza wheels and folding bikes is often a form of X - frame to be found.

Current fads

Because of its good properties (high stiffness at low weight ) of the diamond frame with modifications is used even in fancy bicycles. These modifications are:

• A sloping top tube ( sloping frames) is fashionable, it is with mountain bikes for some time standard and is used lately also in racing bikes. The material saved is to reduce the weight and increase freedom of movement when descending. The weight savings, there is, however, only the case of expensive wheels, since the usual mass-market heavy seatpost even increase the overall weight of the wheel. Another disadvantage is that smaller frames are less rigid than large ones.
• Raised chainstays ( Elevated chain stays) make it possible to place the bottom bracket higher, making the risk of bottoming the pedals is reduced at steeper curve position (see cornering clearance ). However, the rider's feet are no longer sufficient at the traffic lights in this frame geometry on the ground, you have to slip from the saddle.
• The diameters of the upper and lower tube are for materials with poorer resilience such as aluminum increased ( more physical explanation under bicycle frames). A side effect is the larger surface for striking advertising stickers.