I did a trackday at Rockingham a while back and had instruction from a top bloke called Darren, who also happens to work for Mark Holden Motorcycles (http://www.mhmotorcycles.co.uk/).
I took my ZX along for a 16k service today (valve clearance check and all sorts), dropped her off in the morning and picked her up this afternoon. She’s running absolutely fabulously now and has been MOTd to boot… all at a really reaonable price.
Both Mark and Darren are really friendly chaps and explained precisely what had been checked and done to my bike.
I’d recommend these guys to anyone - give em a buzz! They’re based in Bromley - contact details on the website.