Bottom Bracket options.

vadarfone

Hi,

I have got my eye on a Cannondale CAAD 9, but have been reading online that there may be some BB issues with it, regarding BB30.

Now, the last time I was seriously nerdy about bikes was about 10 years ago, when most mountain bikes (my bike of choice) came with a standard Euro BB.

Can anyone who has the time, perhaps talk me through what the deal is with Bottom Brackets nowadays. I have not managed to find anything online that sums it up.

Need some info!

What are all the options available, and how to they work, basically. Some hints on which one to go for as well, would be ace.

Thanks in advance.

vadarfone

Anyone?

Mister W

I'll do what I can...............

There are basically two types of bottom bracket in use. Those with bearings that fit inside the BB shell and those with bearings that fit outside (external). The internal type then split into a number or groups depending on the thread in the BB shell and the spindle. The most common thread is "English" where the threads at each end of the shell go different ways. Then you have square taper spindles, ISIS and Octalink (have I forgotten any?). ISIS is an open standard and Octalink is Shimano specific.

Increasingly bikes now have external bearing BBs. The bearings come in a cartridge that fits into a shell that screws to the end of the BB shell. The spindle is part of the crank and fits through the middle of the bearing. Campag bearing shells are just an empty shell and the bearing cartridge is fitted to the spindle. if you remove the spindle the bearing comes with it. Shimano bearings fit into the shell and the spindle is fitted through the middle. Fortunately everyone has managed to agree on the same fitment for the shells so the same spanner can be used. Then you have BB30 which is an open standard developed by Cannondale. The shell is incorporated into the bike frame instead of being screwed on. The bearing cartridge then pushes into the shell.

That about sums it up I think. As for which one to use... it's up to you. If you're buying a new bike then you will almost certainly get an external bearing BB so it will probably come down to which bike you like and what kit it has. BB30 isn't very widely used yet but don't let that put you off if you like the bike.

vadarfone

Superb!

Thank you.

Answered pretty much everything.

Much appreciated!

So, the CAAD 9, which does not have BB30 is not really an issue then...

Cheers!