Bike Seat Tube Sizes

We usually give four sizes for the complete bicycles and three sizes for the frames.

Bike seat tube sizes.

The seat tube is the long tube that the bike seat post sticks into. Old us bicycles mostly bmx and older bikes that used one piece cranks was 1 25 4 mm. Schwinn bikes come in two variations. This is marked with a minimum insertion mark.

British and italian standard for seat tube diameter was 1 1 8 28 6 mm. As for the saddle the seat tube may be. The seat tube contains the seatpost of the bike which connects to the saddle. While not all bicycle frames have a size label it ll save you some work if yours does.

Seat tube length is the straight line distance between the centre of the bottom bracket and the top of the seat tube. Bike frames are measured from the middle of their bottom bracket to the end of their seat tube. The seatpost must be inserted at least a certain length. Again it s trickier than it sounds.

If the size isn t given. First bicycle frames were made mostly from steel with steel tubes of a standard outer diameter. One size that fits the average population of adults and other bikes that come in different sizes just like clothes. Frames made to british or italian standards will typically have 1 1 8 28 6 mm seat tubes older french bicycles used 28 mm.

The saddle height is adjustable by changing how far the seatpost is inserted into the seat tube. Upanbike aluminum alloy bike seat post length 350mm30 8mm black for mountain bike fixed gear bike seatpost four sizes for you to choose by upanbike 12 99 12. If you look near the bottom of this tube about 3 inches 7 6 cm up from the chain sprocket you ll see a glued on label that states the bike s frame size. 99 13 99 13.

On some bikes this is achieved using a quick release lever. Mountains bikes now come in three different wheel sizes. Older french bicycles used 28 mm tubing. Old american style commonly used on bmx bicycles and other bicycles that use one piece cranks uses a 1 seat tube standard outside diameter accommodates standard lugs and clamp on parts such as front.

Schwinn bikes that come in one size if you are an average sized adult male or female you will be able to fit 90 of schwinn s bicycles that come in a single size. Most steel bicycle frames have tubing of standard outside diameter. The top tube length is measured along the top tube starting at the center of the seat tube and ending at the center of the head tube. You can find them with 26 wheels 27 5 wheels or 29 wheels.

If all three have a 15 frame there will be a height difference between them due to their wheel size.