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... plus its dished, it was designed for a geared freewheel I believe and its threaded on one side only.
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Tomorrow I'll see how close I could get the crank to the BB without a mash of either. IIRC there's only about 4mm or so gap at the moment but I see your point re:- gettting the chainline in the right ball park by reducing the BB axle width further rather than relying purely on Stackbolt spacers at the chainwheel/Spider interface.
Thanks again for your guidance M_V (and everyone else), its much appreciated and is helping me a lot.
EDIT. A further question, are modern cartridge type BB's symmetrical? Is there usually the same amount of axle sticking out of each side when its fitted into a 68mm shell?
If the wheel was originally designed for a geared freewheel then it would almost certainly have been 126mm or wider originally. Sounds like someone whipped some washers out of it to make it ss/track frame friendly but went too far. Best be rid of it sounds. Wheel you linked to looks ok, I think Raleigh probably do a cheaper one but it might not be sealed bearing.
The reason I say using a shorter bb axle would be much better than spacing the chainring is that the crank arm supports the chainring and keeps it centred. Add spacers and I think you'll lose the support and not have the centring effect.
You can get the crank really close to the bb shell without it rubbing by the way. The cranks on my mountainbike are so close that I cannot see between crank arm and bb shell/cup. In fact, I suspect the crank arm is probably sitting inside the bb shell and cup if you see what I mean. You can get things a lot closer together at the bb than you can between the end of the crank arm and the chainstay as there is relatively very little flex at the bb.
As for your last question, the majority are yes. There are a few asymetrical bottom brackets out there but a regular Shimano UN5X or similar will be symmetrical
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M_V
@FatManOnAFixie
Thanks for the input M_V, I appreciate it. I would keep the wrong OLD rear wheel but unfortunately its pretty much pooped. It was the cheapest the original owner could find by his own admission and boy oh boy does it look it! Single wall and buckled enough to make setting up the brakes 'interesting' I've found, the rim is also damaged where he's ridden it with low tyre pressure and it's contacted the road in places by the looks of it plus its dished, it was designed for a geared freewheel I believe and its threaded on one side only. The front is fine, its a modern double walled deep rim and its still true but the rear is bleeeuuugh! I've got one of these on my other bike -> http://singlespeedcomponents.co.uk/wheels/700c-flipflop-black-549.html and it done really well so I'm tempted to buy a 120mm OLD variant and be done with it.
Tomorrow I'll see how close I could get the crank to the BB without a mash of either. IIRC there's only about 4mm or so gap at the moment but I see your point re:- gettting the chainline in the right ball park by reducing the BB axle width further rather than relying purely on Stackbolt spacers at the chainwheel/Spider interface.
Thanks again for your guidance M_V (and everyone else), its much appreciated and is helping me a lot.
EDIT. A further question, are modern cartridge type BB's symmetrical? Is there usually the same amount of axle sticking out of each side when its fitted into a 68mm shell?