Bottom bracket/crank help!

[phantasmagoriana]

At the moment, two of my bikes have lots of "play" in the bottom bracket/pedal area. I've had this problem on one of the bikes before, and had it fixed at the time, but it's happened again.

I'd like to try fixing these, but I'm a newbie when it comes to cycle maintenance and I'm confused by the cranks and bottom brackets: I don't have any special tools for them, and I don't know what I need. The two also appear to be different types. This is what they look like (the first is on an early '90s Raleigh Pioneer; the second is on a Dawes Galaxy, age unknown but probably '80s). I assume a socket wrench is needed on the Galaxy, but don't know where to start on the Pioneer.

Any help on this would be very much appreciated! I may well end up taking them both to an LBS, but I'd prefer to learn how to do things myself at some point...

 

[RecordAceFromNew]

I believe both your bikes have traditional square taper bottom brackets. If you use a coin to release the cap shown in the left photo, you will likely see the same thing as that on the right.

This explains how to remove the crank, so that you can overhaul/replace the bottom bracket.

 

[phantasmagoriana]

Thanks - haven't had the chance to look at them in detail yet, but am quite relieved to know they're likely to be the same type! Looks like I'll be going shopping for a crank puller at the weekend...

 

[phantasmagoriana]

Well, I've taken the cranks and bottom bracket off the Galaxy (had wanted to start with the Pioneer as a test run, but there was an extra bolt that I couldn't work out how to remove, and the Galaxy seemed simpler!).

The bottom bracket was wiggling from side to side quite a lot before I removed it, hence wanting to strip that area down. It came out very easily once I'd taken the cranks off, and appears to be a cartridge rather than a loose bearing one.

I'm now not sure whether I need a new bottom bracket, or whether refitting the existing one will work. There are no numbers or identifying markings on the current one, so if it needs replacing I wouldn't know what size to get. Is there an easy way to measure?

 

[Mark_Robson]

You measure it from end to end and then you measure the Middle minus the tapered cranks, ie 110mm total and 68mm middle.
I hope that makes sense.