IIRC the 'ring is technically a non-speed-limited toll road these days, so you can do round it on anything road-legal you like. Whether cycling on it is all that wise, I don't know. Given the numbers of wannabe Touring Car heroes thrashing ineptly round it I'm not sure I'd want to try, but I'd be interested to hear from anyone who's tried it.
IIRC the 'ring is technically a non-speed-limited toll road these days, so you can do round it on anything road-legal you like. Whether cycling on it is all that wise, I don't know. Given the numbers of wannabe Touring Car heroes thrashing ineptly round it I'm not sure I'd want to try, but I'd be interested to hear from anyone who's tried it.