I got a couple of hours on this yesterday and decided to dismantle it so I can basically go and grab a small bit to work on when I get a bit of time. Also measured up a few bits I'd forgotten about.
Head tube is 185mm which is consistent with how tall the frame is. This should be fine with me with a 32" inside leg.
Chain is indeed 3/32". I took a bit of 1/8" chain round with me and it's definitely wider.
Switching to mm now, other measurements:
Stem: 21.8mm (22mm)
Seat post: 25.0mm
Seat tube: 28.2mm, butted about 50mm down. I'll have to dig out my outside callipers to see what diameter the butting goes to.
Top tube: 26.0mm
Downtube: 28.2mm
Headtube: 32.5mm (bit scaly and crusty so might be 32.4mm)
Spokes: double butted 1.8mm/1.4mm. 36F/36R
Fronts: 276-278mm
Rears: 272-274 on both ds and nds
Front wheel is similar to rear but not the same and has stainless spokes, so it's been replaced at some point.
Misc stuff:
Pedal flats: 16mm
Canti bolts 8mm diameter x 11mm long. M6 thread.
I didn't post this yesterday because it mostly came apart nicely except for a couple of items. One slotted screw on the underside of the rear mudguard didn't want to shift. That was never going to undo nicely tbh. The slot mashed up and the head sheared off when I got a grip on it. I can get the screw part out later with an Easy Out or just drill it and easily re-tap it since it's metric. The derailleur put up a bit of a fight and I'll have to chase the threads on the mounting stud before it goes back on. Last up was the cranks. My crank puller is at work but I'm 90% certain the internal threads are bigger diameter than usual. I got the non-drive side to shift with a small windscreen wiper puller, which is a bit like a slim balljoint breaker. It was on pretty tight and went with a right bang! But I couldn't move the drive side crank. The puller went behind the spider ok but it was just on the taper too tight and was bending the legs open on the puller. The head on the axle bolt then snapped off with an almighty bang because it had worked off-centre and I stopped at that point before I damaged anything else. I'm annoyed at breaking the bolt, but it's not the end of the world. I have an idea how I can reinforce the puller, by welding on a piece of 5mm thick angle carefully cut to the same shape as the underside of the crank and puller. It'll stop it opening up and I'll make up a small square packer to go on top of the axle with a divot drilled into it to locate the bolt in the puller. A bit of controlled heat from the heat gun will help too, since it's alloy. I'll get it off.
My hands are trashed. That thin flaking chrome is like a million little razor blades. But to end the post on a more positive note, here are some random dreadful pics.
Remnants of the Vitus logo on the fork:
Where the internal wiring goes through the fork and into the frame:
(The 36 is the frame number I think. I haven't found any numbers anywhere else yet)
Pedals need adjusting and re-packing with grease but look pretty good inside:
Chainrings:
Can't remember why I took a pic of this for reference. It's no help whatsoever:
The frame out in the sun: