Is the rear sprocket a standard part available anywhere?

I'm planning out some touring, feel this part is worn, so I'm looking to understand if I should buy one in the UK and get it sent out, or if I can rely on foreign mechanics having access to such a part.

I guess what I mean is, is the part standard or not, ie. used on many bikes, or specific to the CB?

thanks

http://www.jtsprockets.com/catalogue/sprocket/JTR1332/

All these bikes use the same sprocket as the Cb500, the only difference is tooth size, you can run upto a 42 tooth on a standard length chain, and maybe a 39 tooth depending on how much adjustment you've got left. A 42 tooth will bring the adjustments more towards the engine as a 39 will be more towards the end of the adjustment

Right. that looks like a moderately specialised piece of kit, worth bringing along...

So, would I be right that 42 teeth is a good call, since it would give the longest chain life, as the thing has longer to stretch?

Also hope your Bavarian escapade went / is going well. I am part way through Spain, had to fly back for family reasons, bike locked up in madrid. Have to say, Spain is an absolute dream. Roads pristine, long, straight, empty, enough mountains to keep things interesting, beautiful culture.... recommend it.

In a certain way I think a chain-oiler and oil might be a better investment/better thing to carry with you. Ignore me if you've already thought of that.

Having a few spare stashed at home that can be mailed out sounds like a good idea if you are going on 'that kind' of long trip. Assuming you plan on keeping the bike after the trip you'll use the chain/sprockets at some point...