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Questions and answers about sports

Bottom Bracket Compatability Question

5 min read

Asked by: Ivan Greene

How do I know if my bottom bracket is compatible?


Quote from video: Inspect inside the shell of the frame. If the frame shell is smooth on the inside it is a press fit shell. The bottom bracket is a thread together style bottom bracket which has its own video here.

Can I use a 68mm bottom bracket in a 73mm shell?

Multiple spacers are included in order to fit both sizes meaning if you see a BB for sale that says 68/73 it means it will fit both but it includes a couple spacers in the box to make it fit the 68, those spacers (or fewer of them) are not needed if the shell is 73mm wide.

Do all bottom brackets fit all bikes?

To a certain extent which bottom bracket you end up buying is up to what kind of frame you have. Certain frame materials and drivetrain options only support one type of Bottom Bracket. There are two main types of bicycle bottom brackets in today’s market, namely, threaded and press-fit BB’s.

Is BB30 compatible with Shimano?

Our Shimano BB30/PF30 68mm ROAD BB. It is compatible with Shimano™ Hollowtech II cranks. High-grade Enduro 2437 steel bearings are fully sealed and are a fantastic replacement BB for your Shimano™ drivetrain.

How do I know if my crankset is compatible?

In most cases three-and two-piece cranksets are compatible with the same bottom brackets so long as the axle is the same diameter. They are commonly used in conjunction with the mid-style bottom bracket standard. One-piece: This is where the axle and crank arms are a single piece of steel.

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 many spacers should a crankset have?

If your BB shell width is 68mm wide then you need three 2.5mm spacers to properly align your BB/crank and get a proper chainline (two on the left side and one on the right). If your BB shell is 73mm wide you need one 2.5mm spacer (on the right) to properly align your BB/crank.

Do I need BB spacers?

Much like GXP, you don’t need to add any spacers to the bottom bracket if you have a 73mm shell, but you will need to add a 4.5mm spacer to the right-hand side of the crank axle, unless you’re using a chain guide, in which case a 2mm spacer is required instead, along with a 2.5mm spacer on the right-hand side of the

Are bottom brackets interchangeable?

Threaded bottom brackets shells have been made over time in various thread standards that are not interchangeable. The common threaded bottom bracket uses cups or adapters with the thread specification of 1.37″ x 24 threads per inch (approximately 34.8mm diameter).

Are all bottom brackets the same size?

There are 4 widths available with BSA bottom brackets; 68mm, 73mm, 83mm or 100mm. This bottom bracket clearly shows you on the outside what bearings have been fitted to the bike. 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.

Can I fit a BB30 bottom bracket?

BB30 fits into a 42mm shell—a shell with an internal diameter of 42mm. PF30 bearings fit into bb shells with an internal diameter of 46mm.

Do all cranksets fit all bikes?

Crankset compatibility. You can replace the chainrings on your crankset, but not all chainrings will fit all cranks. First, different cranksets may have a different number of arms or direct-mount interfaces (connecting the cranks to the chainrings), and they may be positioned differently.

Can I use an 11 speed crank on a 8 speed bike?

Nominally no, an 11 speed speed crank will not work with an 8 speed drivetrain.

Can I put a bigger crankset on my bike?

Yes, you can. This will make it suitable for diverse terrains and make pedaling easier. Putting a smaller chainring on your road bike isn’t a problem but you may have to change your crankset.

Are bottom brackets interchangeable?

Threaded bottom brackets shells have been made over time in various thread standards that are not interchangeable. The common threaded bottom bracket uses cups or adapters with the thread specification of 1.37″ x 24 threads per inch (approximately 34.8mm diameter).

Do all cranksets fit all bikes?

Crankset compatibility. You can replace the chainrings on your crankset, but not all chainrings will fit all cranks. First, different cranksets may have a different number of arms or direct-mount interfaces (connecting the cranks to the chainrings), and they may be positioned differently.

Are all bottom brackets the same size?

There are 4 widths available with BSA bottom brackets; 68mm, 73mm, 83mm or 100mm. This bottom bracket clearly shows you on the outside what bearings have been fitted to the bike. 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.

Can I fit a BB30 bottom bracket?

BB30 fits into a 42mm shell—a shell with an internal diameter of 42mm. PF30 bearings fit into bb shells with an internal diameter of 46mm.

Will a BB30 fit a 68mm bottom bracket?

While both standard BSA threaded frames and BB30 frames have 68mm shells for road bikes, the external bearings of the BSA frame when used with an outboard bottom bracket would render a standard BB30 crankset’s spindle too short to use with a BSA30 bottom bracket.

What is the difference between BB30 and BSA?

BSA is English standard and have screw thread inside the hole ,usually use in shimano,while BB30 is Italian standard and don’t have screw thread, usually use in CP.