Nylon washer, topped with a steel washer, then tighten up as tight as you like. If you can fit chain tensioners, then they will help to hold everything in place much better
![Wink ;)](http://www.radbmx.co.uk/forum/Smileys/smilies/wink.gif)
But one good tug with a normal size spanner is enough. No ratchets, no long bars or owt, just one good tug. A 'polite nip' as we would say in the motor trade
![Smiley :)](http://www.radbmx.co.uk/forum/Smileys/smilies/smiley.gif)