motorcycle exhausts uk

What are the minimum specifications for a motorcycle to be ’street legal’ in the UK?

Hi – I’m thinking of customising some old bikes and I’d like to know what are (or where I can find) the minimum requirements in order to make a bike legal.

As it’s my first build, it’ll be an old 125cc. I don’t know whether engine capacity matters but I know that exhaust noise does. I am assuming headlamp, back light, turning lights…is a speedo/rev counter necessary?

You get the idea. Any help will be much appreciated

Cheers!

hi,if it passes an mot then its street leagle…hope this helps..ps,if its a trail bike [like xt500] then indicators arnt required for the mot….acctully you dont need any lights what so ever if you go for a daylight mot.