What Is The Bottom Bracket Spindle?

What is the bottom bracket spindle? The bottom bracket on a bicycle connects the crankset (chainset) to the bicycle and allows the crankset to rotate freely. It contains a spindle to which the crankset attaches, and the bearings that allow the spindle and crankset to rotate.

How do I determine bottom bracket spindle length?

Pull off both crank arms, then measure the spindle of the BB, that's what the Shimano Crank is saying it needs. When you measure spindle length, you need to only measure to the ends of the square taper. Some spindles have threaded bits that extend beyond the square taper. Don't include those in that measurement.

Does spindle length matter on bottom bracket?

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.

What length spindle do I need?

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. If you are using the Outboard BB and the Spline Drive Sprocket, and you BB shell measures 68mm wide, you need the 5 5/8″ Spindle.

What are spindles?

Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis. During mitosis, the spindle fibers are called the mitotic spindle.


Related guide for What Is The Bottom Bracket Spindle?


How do you replace a bottom bracket spindle?


How do I know what size bottom bracket I need?

To find out the size of bottom bracket needed, measure the inside of the bottom bracket shell in your frame, it will be 73mm, 70mm or 68mm. Some older frames may have Italian threaded bottom brackets, instead of the more modern English.


What is spindle length?

Spindles are also specified by spindle length, which is simply the length end-to-end. As an example, a particular bottom bracket may be specified with a 47.5mm chainline, and a 113 spindle length. A crank arm designed for use with this spindle will have the middle of the crankset 47.5mm from the bike center line.


Can you change spindle length?

Depending on the crank design, the spindle length can vary. 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. So if you really “need” a 118 mm spindle, but only can find a 121 mm, that isn't a big deal.


What size is an American bottom bracket?

BMX Bottom Bracket Shells

Bottom Bracket Type Cup ID/Bearing OD
American Press-Fit 51mm
Spanish Press-Fit 37mm
Mid Press-Fit 41mm
Euro Threaded

Where are spindles used?

On a lathe (whether wood lathe or metal lathe), the spindle is the heart of the headstock. In rotating-cutter woodworking machinery, the spindle is the part on which shaped milling cutters are mounted for cutting features (such as rebates, beads, and curves) into mouldings and similar millwork.


How do spindles work?

A spindle provides the twist that turns fiber into yarn. When using a hand spindle, your hands let the fibers slide past each other and then let the twist catch them, a process known as "drafting." The size of the yarn is determined by how much fiber is caught in the twist.


Is a spindle a wheel bearing?

Some people generally refer to them as a spindle but they mean the same thing. When you look up a replacement, look for "knuckle" or "wheel bearing housing".


How do you know if your bottom bracket needs replacing?


What bottom bracket does giant use?

Giant Bicycles has a long collaboration with Shimano. It is no surprise that Giant's frames follow the BB86 and BB92 standard developed by Shimano.


Can I use Shimano bottom bracket with SRAM crankset?

If you do indeed have a SRAM GXP press fit BB, then you can't adapt that to a Shimano crankset. You would need to have someone press out the BB and install a new one to make the Shimano crankset work. You would look for a BB86 bottom bracket.


What bottom bracket is compatibility chart?

1. Compatibility of bottom brackets

BB standard Crankset compatibility
1 b) BB30A Hollowtech II, BB386EVO, BBright, BB30 if they have spacers on the left side
2. PF30, OSBB Hollowtech II, BB386EVO, OSBB, BBright, BB30
3. BB86, BB90, BB92 Hollowtech II
4. BBright Hollowtech II, BB386EVO

Where do the spacers go on a bottom bracket?

For a bottom bracket shell width of 89.5mm, insert the 2.5mm spacer into the right hand side (between the frame and the right hand adapter). Use the inner cover. bottom bracket shell, it should be installed with the inner cover sleeve to prevent possible contamination.


How do you use spindle spacers?


What is a threaded bottom bracket?

Threaded bottom brackets use a shell with internal threads to hold threaded parts. The frame shell may be threaded directly at the shell, or there may be an insert installed that has internal threads. Threaded bottom brackets shells have been made over time in various thread standards that are not interchangeable.


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.


Are all BMX spindles the same?

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.


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