Identifying correct bottom bracket for a bike

[Korschtal]

Greetings from Germany...
I followed a link here from bikehacks.com, it's a great resource, thanks...
I'm getting back into bike maintenance after a long time of taking it to a shop because of a lack of confidence on my part. I'm about to tackle the bottom bracket, It's an unsealed, cup and bearing type, and I was wondering how I can find which cassette would be the best to replace it. Is this a standard size, or does it depend on maker and age of the bike?
Thanks for any help received...

[Alex Ramon]

Bottom bracket spindles come in a lot of different sizes. Once you get the spindle out of the bike, take it down to your local shop where they should be able to match it up with the right replacement spindle.

[cschauerj]

So... If one was upgrading from a cup and cone type bottom bracket to a cassette and didn't want to take it to a local shop what measurements besides the threads would one need. This is a do-it-yourself website after all, isn't it?

[Alex Ramon]

While I can explain how to replace the spindle yourself, sometimes it's a little trickier to size up replacement parts without having them in front of you. This is especially true for bottom bracket spindles. That is why I recommend taking it to a shop that has a good selection of replacements to choose from. When I worked in bike shops this is how I did it. Perhaps someone else has a better method?
Sheldon Brown has a <a href="http://www.sheldonbrown.com/bbsize.html">bottom bracket sizing database</a> that might help.

[cschauerj]

Ok. Thanks Alex. I'll check out the Sheldon Brown website as well as Pricepoint.com's product help page. If I can't find the answers then I'll end up taking it in.

[DaveM]

When you pull out the old spindle, there will likely be a code stamped on it that identifies the size. Something like "D-EL" or a similar short code. Searching for this code should help you identify the exact specs. The two main issues are total length and offset (meaning how much longer the drive side is than the non-drive side measured from the bearing surface). You can hand measure these, but the stamped code should contain this information.

[cschauerj]

The spindle was labeled with D-3H and G-8. I was hoping they identified something. I'll do some hunting. Thank you.