Which bottom bracket do i need

Both of these pressfit style bottom brackets have their own issues, creaking and cost of manufacturing to name a couple. While working great, many compaies in the mountain bike world have gone away from BB30 or PF While having the large bearings and working great with 30mm spindles, riding in dirt, mud and harsh conditions cause failure much faster. Understanding everything about BB's in less than 1 minute A lot of road bikes and fat bikes use specialty sizes.

For example, some fat-bikes from Surly utilize a mm and mm shell width. These are all the more reason to make sure you are getting the correct brand and size when purchasing the correct bottom bracket. If you aren't confident you're buying the right size BB for your bike, please ask us. We deal with this stuff all day every day and are happy to help ensure you get the right stuff for your bike. The majority of crank spindles come in either a 24mm or 30mm diameter.

Below are some of the most popular brands and sizes. All in all, after reading this you've got some proof that bottom brackets are a confusing topic. While they certainly are not getting easier, we have tried to help clear up some issues and possible give some knowledge about picking what works for you. If you've found your answer here, awesome!

Go get yourself some fresh new bike parts. If you've still got questions, please don't hesitate to contact us. We can help you figure out your BB size, spindle size, what cranks fit your bike, etc. We eat, sleep and breathe bicycles so rest assured, we'll figure it out :. Home Menu Search. Continue Shopping Your Cart is Empty.

Shop Watch Read. It sits inside the part of the frame called the bottom bracket shell. The bearings are held in the shell by an adaptor or a cup. The spindle connects the two cranks to one another and to the bearings.

In order to service the bottom bracket system, it is necessary to know what type it is. Bottom brackets standards can be difficult to identify. There are many different models that look similar and several different standards. Additionally, we recommend reading the repair help article at parktool. Although in some cases, the bottom bracket type can be identified while the bike is together, it is sometimes necessary to first remove the cranks to perform a better inspection.

NOTE : There will always be new standards and new tool fittings coming out. You may need to contact your manufacturer or visit your local bike shop for more information.

Press fit bottom bracket systems use a frame shell with a smooth bore, without any threads. Adaptors or cups containing bearings are pressed into the shell. There will be no tool fittings visible from the outside in a press fit system. Some older frames may have Italian threaded bottom brackets, instead of the more modern English.

The bottom bracket is the bearing system between the cranks. It sits inside the part of the frame called the bottom bracket shell. The bearings are held in the shell by an adaptor or a cup.

The common threaded bottom bracket uses cups or adaptors with the thread specification of 1. As for a bottom bracket, on the low end, maybe miles. But sometimes you get unlucky and get a bottom bracket that lasts maybe miles. Road bikes usually have a BB drop of between mm. Most road bikes designed for racing and 23c tires fall between mm.

Do normal maintenance, keep things properly lubed and your BB should last for another 4, miles or more. The higher the bottom-bracket height, the higher the centre of mass of the rider, and so the more the bike tends to pitch when faced with bumps, hard braking or steep gradients. In this sense, a lower bottom bracket improves stability in much the same way as a longer wheelbase.