chain hits stay with new wheel/gearing

So I'm building up an old mixte and get to putting on the chain and then the top side of the smallest cog is making the chain rub on the middle stay.

Normal.

Rub.

I'm not great at cassette spacing so just went with 8 speed as a good number, should I have gone with 7, 9?

Parts.
http://www.grahamweighcycles.com/gwcshop/product.php?id_product=890 - wheels
http://www.amazon.co.uk/Shimano-Acera-ECSHG418130-Speed-Cassette/dp/B00518SHQA/ref=sr_1_2?ie=UTF8&qid=1411753365&sr=8-2&keywords=cassette+8+shimano - cassette 11-34

hmm, did you have to spread the rear to fit the wheel? what is the natural width of the rear dropout 126mm 130mm? and what does the hub measure? is the dish of the wheel right so the wheel rim sits centrally? seems odd an 11t wont clear the stay, i could understand if it were a bigger cog.
Maybe spacing of the hub needs adjusting and then maybe redishing the wheel.
Maybe theres a spacer behind the cassette.
but overall it looks like the freehub or freewheel whichever it is is just too long. Maybe it can only take uniglide not HG?. Youre going to have to do some kind of hack if you want to fit the wheel.

130mm from what I can tell but the frame when I got it had done the rounds a bit so might have been made wider in the past. Was originally 27 inch wheels.

Wheel sits fine, I'm using an adapter claw which moves it forward a little in the dropout but that shouldn't matter as I think all the other options would do that?

No spacer behind the cassette or any weirdness going on there.

I dunno if it matters/helps but it's the middle stay on the mixte so the bar that runs from the back to the headset.

8 and 9 speed cassettes are the same width but different spacing, a 7 is the same spacing as an 8 but one cog less. On a 7/8/9 hub you use a spacer for a 7 speed instead of the 8th cog.
Can you put a spacer instead of the 8th cog? Depending on your cassette it might be riveted together and you won't be able to.
Would need to adjust the limit screw on the RD so you don't shift off the cassette by accident.
Or just adjust the limit screw so you can't use the 8th cog... Effect is the same as making it 7 speed.

I'm thinking buy another pair of track wheels like on my bike and just tell her to live with picking 1 speed...

Can think of a handful of bodges but rather it all worked perfectly as gf will be riding it and so "don't shift all the way up" will be followed with forgetting and stuff broken.

Nah, you can set the limit screw so it won't go on to the tiny cog. she'll never miss it unless she starts promuting down the big hills!

Adjusted with no cable on(moving mech by hand) to do limits and the no top gear option seems good. What will happen with the extra on the shifter? When it gets to the end gear will it throw them out of index?

My choice would be to index the gears 1 gear out of sync so that top gear on the shifter (cable all way out) aligned with 2nd from top gear on the cassette. This would avoid the cable going slack if you 'shifted' to the gear you won't be using. At the other end the limit screw on the mech will prevent you shifting I to the spokes.

@mechanical_vandal yeah I'm guessing she will be at that end of the gearing more might never ever use the lowest 24/34 MEGARANGE!!!!!

Also with changing the handlebars, saddle and stuff it now looks more like a bike just have to wait on some cable outers to be delivered, find a little |_____| shape plate thing to fit a pannier, borrow drill for the front brake, get some brake levers that fit/feel nice with the triggers and away we go.