Sigma sport is your best bet.
Cheers, although I probably should have mentioned I'm in Hackney. Sigma Sport is quite a trek away.
Do you have a bike? It's not that far!
You could stop at sigma on your way to giro cycle cafe. They normally have attaquer and a few others
@Jezston started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Sigma sport is your best bet.