BSA, or English threaded bottom bracket, is the most common threaded standard in use today. It uses a 68mm wide shell for road bikes, 73mm on mountain bikes, with a 34.8mm diameter shell. A few bike brands use an Italian threaded bottom bracket but these are rare.
How do I know what 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 a 68 73 bottom bracket?
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.
Are BB30 and PF30 the same?
A PF30 frame has a shell slightly larger than BB30 (46mm compared to 42mm). The bearings are pressed into cups which are then pressed into the frame. In the case of the PF30 systems the bearing cups rely on flanges to ensure that both cups are pressed the proper depth into the frame.
What is the difference between BB30 and BB86?
Measure your BB shell width - BB30 shell is usually 68mm wide whilst BB86/90 is 86.5mm i.e. you may need a spindle 18.5mm longer. For press-fit BBs for 41mm dia shells and 30mm spindle, the bearings are very small so don't expect them to last very long.
35 related questions foundWhat cranks fit BB86?
SRAM's GXP cranks are well suited to BSA and BB86 bottom brackets, hence the company has hardware to suit. These cranks can be fitted in larger shells however owners will have to look elsewhere for suitable hardware. BB30 cranks are best suited to large diameter shells such as BB30, PF30, and T47.
How wide is BB86?
The road standard has an 86.5mm shell width (hence BB86) whilst the mountain bike standard has a 91.5mm shell width. A number of other shell widths may also exist, though they all use the same bearing cups. More recently, bearings have shown up that allow a 30mm spindle to be used.
What cranks fit PF30 bottom bracket?
This bottom bracket fits any Shimano crank on a PF30 frame.
What cranks fit PF30?
The PF30-SHIM adapts 24mm Spindle Cranks (Shimano, FSA, etc.) to work on Pressfit 30 frames. Simply tap the adapters into the 6806 bearing in the BB shell, install the spindle and cranks.
What is dub groupset?
In 2018, SRAM introduced mountain bike cranksets which use a new technology name DUB™ (Durable Unified Bottom Bracket). Meant to simplify frame BB and crankset compatibility across their product lines, it brought about yet another standard to understand.
Can I use a 68mm bottom bracket in a 73mm shell?
You could install it, but it will shift your chainline, shift the centerline of your feet, clearance issues might arise on the non-drive side, and you might be leaving some BB shell threads exposed on the non-drive side as well.
What does the 90 in BB90 refer to?
BB90 and BB95
The numbers 90 and 95 refer to nominal shell width. This unique bottom bracket shell is not a straight bore but has an internal bearing retainer built into the shell, similar to an integrated headset. Bearing outside diameters are 37mm. BB90 shell and bearing with spindle and bearing removed.
What is BB 92?
BB92 refers to the bottom bracket shell width, specifically: 41mm BB shell diameter. bearing with a 24mm internal diameter. 24mm diameter spindle on the crank.
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.
How do you know when to replace bottom bracket?
To check if your BB needs replacing, drop the chain off of the smallest chainring and spin the cranks. If there's a side-to-side wobble, or feeling of grittiness, it's time for a new one.
Are bottom brackets all the same size?
There are 4 widths available with BSA bottom brackets; 68mm, 73mm, 83mm or 100mm.
Are all hollowtech BB the same?
Since the spindle is part of the right crank, there's no issue of compatibility. All Hollowtech II cranks work with all Hollowtech II bearing units. Any crank that fits on one type of spindle will fit on all spindles of that type, but if the length is incorrect, the chainline/clearance will vary.
Can I use BB30 instead of PF30?
Yes, just switch out the crank. The frames are constructed differently. BB30 uses bearings that sit in the bb shell and are held in place with snap-rings. PF30 uses a one piece bearing and composite cup that presses into the bb shell.
What bottom bracket does Cannondale use?
Cannondale Ceramic Bottom Brackets
Cannondale are the inventors of the BB30 bottom bracket standard. Over the years they have used PressFit30 in their carbon road and mountain bike frames to reduce the weight. Most recently, most of their frames follow the BB30A or PF30A standard, which is exclusive to Cannondale.
What is a press fit 30 bottom bracket?
PressFit 30 (PF30) bottom brackets have a frame shell width of 68mm for road bikes and 73mm for mountain bikes. Inner diameter is 46mm. The PressFit 30 has been widely used by many manufacturers over the years. From Cannondale and Specialized all the way to the small scale frame builders.
Are SRAM and Shimano bottom brackets compatible?
SRAM DUB bottom brackets aren't compatible with Shimano cranks either. DUB bottom brackets are designed for a 28.9mm spindle. And since Shimano cranks rely on a 24mm spindle, a combination of the two results in a non-secure fit.
Is PF86 and BB86 the same?
BB86 and BB92 are much more commonly used, as is the identical PF86 and PF92. Shimano's naming convention for its press-fit bottom bracket parts is confusing, to say the least.
What size are BB86 bearings?
A BB86 shell is 41mm and a 6806 bearing is 42mm on the outside diameter.
What size bottom bracket do I need for my BMX?
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. This size of your bearing will be depending on the brand of your cranks as some brands will make a specific size only.
