Depends where in London you are/are going and what you are after.
Sondel Sport at the top of Islington is friendly but mostly high-end stuff.
http://www.sondel.co.uk/ J&S in Greenwich is quite an aladdins cave.
http://www.jsaccessories.com/ Rivetts in Leytonstone is okay. Not very big though.
http://www.rivetts.co.uk/ Harpers in Romford okay as well. Also pretty small.
http://www.harpersraceshop.co.uk/cat14_1.htm Of the four, only J&S is worth going out of my way for (unless I want something Dainese, which is about every 3 years).
Hybrid Mode
