I know this gets asked alot but I'm asking about the older straight top tubed model.
M8 is 5'10" and I would imagine at 18" is the one to go for, but as I hadn't seen him for a while (years actually) when he emailed me yesterday I thought he was shorter than that so recommended looking at a 16".. which he's now doing… before he buys it on my (crap) advise, can anyone confirm 'probably' fit an 18 better than a 16?
(I know he should go and try one, but he's look at buying one offa fleabay.. so no chance to try before hand)

also are there any known problems with the 'older' 5's?

I'm 5'10 and my old 5 fitted spot on.

The old ones come up big, so, as Chunky says, it'll fit fine. Biggest issue is top tube length, but he'll be fine.

I'm 5.10 and I ride an 18 5' with straight top tube. Fits me fine, a 16 would be way small, my prefered size is 17 but you takes what you can get (mine was an ex-demo cheap deal).

cool thanks guys, I've re-stated he needs an 18, nice looking 16" (in brand new condition?) on fleabay if anyone want one.

Older fives were designed around shorter forks IIRC.

I'm 6ft 1in with a 32 inch inside length. So I'm stumpy of leg, long in body 🙂 My 18 inch 2006 model Orange 5 (the year before they went all trendy bendy), fits me just fine.

B.

I'm 5ft 10in with a 33 inch inside leg, so stumpy of body and long in leg 🙂 . My 18 inch 2004 model felt a wee bit large.