What is the difference between a 19mm and 22mm bottom bracket?

A 22mm bottom bracket only has a 3mm larger diameter. All this means is that you can’t run 19mm spindles on the bottom bracket. Since the opening is a little bigger, there is very very minuscule weight savings. However, most weight savings will come with a more hollow 22mm spindle.

What do bottom bracket sizes mean?

The 68mm and 73mm dimension measure the width of the bottom bracket on the frame of the bike with no BB installed, simply the width of the shell. Most road bikes that use a threaded bottom bracket measure 68mm wide and most cross country/trail mountain bikes measure 73mm.

When a bottom bracket size is listed as 1.37 x24 What does the 1.37 measurement refer to?

It describes the thread of the bottom bracket. 1.37 stands for the thread diameter and is measured in inches. 24 stands for the pitch size (the distance of the thread in one turn). It’s measured in TPI, threads per inch.

Are bottom brackets all the same size?

There are 4 widths available with BSA bottom brackets; 68mm, 73mm, 83mm or 100mm. For road bikes, a BSA bottom bracket is always 68 mm wide. Other sizes, and particularly the 73 mm width, is commonplace with mountain bikes. The 83 mm and 100 mm dimensions have become rare these days.

How do I know what size BMX bottom bracket I need?

BMX frames are made in a variety of sizes and shapes and the tubing where the bottom bracket fits is no different. Bottom brackets for BMX bikes come in 19mm, 19mm mid, 22mm, 22mm mid, and 24mm. Basically, this size refers to the size of the spindle that will pass through the bearing and allows the cranks to spin.

What size spindle do I need BMX?

A: The Short Answer: If you have a Mid or a Spanish BB on your BMX Freestyle bike, you need the 5 5/8″ spindle. If you have an American BB on almost any style of frame, you need the 5 5/8″ spindle.

What spindle length do I need?

The best way to find out which spindle length you need is by looking up the specs. (The alternative is trial and error…) Spindle length and the resulting chainline have some leeway. If you are within 2-3 mm of the “correct” 43.5 mm or 45 mm, you are doing quite well.

What does the 30 in BB30 refer to?

The term PF42 refers to the inside diameter of the shell. The term BB30 was an early term in the history of this standard and refers to the 30mm diameter of the spindle used at that time.

Does bottom bracket spindle length matter?

The critical thing is your spindle length: as long as you can set up the correct chainline you will be good to go. But, again, best never to mix standards if you can at all avoid it. If you are looking to replace a cottered crank setup with a square taper setup, then look no further than a cartridge bottom bracket.

How do you measure bottom bracket?

Measuring the Bottom Bracket Shell. To measure the bottom bracket shell on the bike frame, flip the bicycle upside-down and hold the ruler or calipers against the shell. Measure the length of the shell from end to end, not including the length of the spindle inside the shell. Most bottom bracket shells measure 68, 70 or 73 mm long.

What are the sizes of bottom brackets?

Bottom brackets are sized based on two measurements: spindle length (for cartridge bottom brackets only) and shell width. Spindle lengths vary anywhere from 102 to 140mm. Shell widths come in 68, 73 or 83mm widths.

What are the different types of bottom brackets?

Threaded systems can use internal bottom brackets (ISIS, square-taper, or Octalink) or external bottom brackets (Shimano Hollowtech, SRAM GXP, Campagnolo Ultra-Torque). English (BSA) and Italian thread configurations are available, and are not cross-compatible.

What is a road bike bottom bracket?

A bicycle’s bottom bracket sits inside the bottom bracket shell, and it is basically comprised of a set of bearings that support a spindle which the cranks attach to and spin freely on. For as long as we can (or need to) remember, the ‘standard’ road bike bottom bracket consisted of a squared,…