Bicycle frame

A bicycle frame is the main component of a bicycle,while straddling the bike and standing on the ground is
onto which wheels and other components are fitted.called clearance. The total height from the ground to
The modern and most common frame design for anthis point is called the standover height.
upright bicycle is based on the safety bicycle, and isDown tube
made of two triangles, a main triangle and a pairedThe down tube connects the head tube to the bottom
rear triangle. This is known as the diamond frame. Thebracket shell. On racing bicycles and some mountain
main triangle consists of the head tube, top tube, downand hybrid bikes, the derailleur cables run along the
tube and seat tube. The rear triangle consists of thedown tube. On older racing bicycles, the gear levers
seat tube, and paired chain stays and seat stays. Thewere mounted on the down tube. On newer ones,
head tube contains the headset, the interface with thethey are integrated with the brake levers on the
fork. The top tube connects the head tube to the seathandlebars.
tube at the top, and the down tube connects the headBottle cage mounts are also on the down tube. In
tube to the bottom bracket shell. The rear triangleaddition to bottle cages, small air pumps may be fitted
connects to the rear dropouts, where the rear wheel isto these mounts as well.
attached. It consists of the seat tube and paired chainSeat tube
stays and seat stays. The chain stays run parallel toThe seat tube contains the seatpost of the bike, which
the chain, connecting the bottom bracket to the rearconnects to the saddle. The saddle height is adjustable
dropouts. The seat stays connect the top of the seatby changing how far the seatpost is inserted into the
tube (often at or near the same point as the top tube)seat tube. On some bikes, this is achieved using a
to the rear dropouts.quick release lever. The seatpost must be inserted at
Unless otherwise specified, the remainder of this articleleast a certain length; this is marked with a minimum
focuses primarily on the diamond frame.insertion mark.
The diamond frame consists of two triangles, a mainThe seat tube also may carry bottle cage mounts.
triangle and a paired rear triangle. The main triangleChain stays
consists of the head tube, top tube, down tube andThe chain stays run parallel to the chain, connecting the
seat tube. The rear triangle consists of the seat tube,bottom bracket shell to the rear dropouts. When the
and paired chain stays and seat stays.rear derailleur cable is routed partially along the down
Head tubetube, it is also routed along the chain stay. The chain
The head tube contains the headset, the interface withstays provide a mount for rear disc brakes.
the fork. In an integrated threadless headset, theSeat stays
bearings interface directly with the metal surface onThe seat stays connect the top of the seat tube
the inside of the head tube.(often at or near the same point as the top tube) to
Top tubethe rear dropouts. When the rear derailleur cable is
The top tube connects the head tube to the seat tuberouted partially along the top tube, it is also routed along
at the top. In a mountain bike frame, the top tube isthe seat stay. One combination aluminum/carbon fiber
almost always sloped. In a traditional-geometry racingracing frame design uses carbon fiber for the seat
bicycle frame, the top tube is horizontal. In astays and aluminum for all other tubes. This takes
compact-geometry frame, the top tube is sloped. Seeadvantage of the better vibration absorption of carbon
Road and triathlon bicycles for more information onfiber compared to aluminum.
geometries.A single seat stay refers to seat stays which merge
Control cables are routed along mounts on the toponto one section before joining the front triangle of the
tube. Most commonly, this includes the cable for thebicycle, thus meeting at a single point. A dual seat stay
rear brake, but some mountain bikes and hybrid bicyclerefers to seat stays which meet the front triangle of
also route the front and rear derailleur cables along thethe bicycle at two separate points, usually side-by-side.
top tube.The seat stays also provide a mounting point for the
The space between the top tube and the rider's groinrear rim brakes.