Rat Bikes! Pub Bikes Beaters! Frankenbikes!

Front mtb bolt on cog disc hub conversion thing, half links in the chain for tension

vertical dropouts?
If so, buy a single half-link and round file, choose your gear carefully, get a worn-in (i.e. pre-stretched) but solid 1/8" chain to the closest possible length, only a bit too short (you may or may not need the half-link to do this), and then file the dropout the rest of the way. You'll only be filing <0.25" (6mm) from the dropout so it won't really weaken the frame.

wheels
If you're really lucky and it's a very crap MTB you may have a screw-on freewheel in which case you can use Loctite and a BB lockring to do the job. If it's a cassette freehub, you might be better off swapping out the hub....
I've heard of people jamming up the ratchets of a free-hub body with jb-weld, in which case you'll need a single-speed cassette adaptor.
If the back wheel is of high quality you may also consider a Surly fixxer which cost about £40 (IIRC) and converts a shimano free-hub wheel to fixed.
another potentially cheap fixed wheel option might be to get a cheap front wheel with disc brake bolts and swap out the axle/cones for the ones in your MTB rear wheel.
Hope this helps - I've done the dropout filing, the BB lockring ghetto-fix, and also the front disc-hub-to-rear-fixed too.

the photo has been rotated 90degrees clockwise

Bizarre way to lean your bike up then.

And the other one confuses me still, looks like the wheels are right in at the bottom of the wall but then how is the bike upright? Maybe wall slopes away?

@ rogan: It's a small, in white with green logos

@ rogan: It's a small, in white with green logos

let me know if you do..
not arsed on condition...

Love the Peugeot build, But is the seat tube warped from welding? Cant tell...

Love the Peugeot build, But is the seat tube warped from welding? Cant tell...

I think its just an illusion from the burn marks.

Why am I into this so much? And the peugeot?

Cheers Rik, I might make that my spring/summer project! I don't even have a frame yet but I'm watching a few on eBay with not long left and very low bids. If I could make the whole thing cost less than £50 I'd be happy.

the seattube on the deathtrapeugeot is straight, just checked cause it looks a bit weird in the photo. have just been to a short ride with some mavic bullhorns fitted. could be nice with a bit shorter stem. frame feels not overly soft, pretty decent for a homemade frame made with hardly any measurements. wheelbase is 97cm...

My new beater. Still haven't had a chance to ride it though, there's 3ft of snow here (Finland). :)

Cant stand that if I'm honest :/

Nerged for racism.

Fins are good with bikes it seems

Nerged for racism.

Pffff.....seriously? whatever.

Yes seriously, it's not acceptable man.

@mancesco froser

Did you weld it just with electronic welding or did you use special tools?[URL="http://www.dict.cc/englisch-deutsch/electronic+welding.html"][/URL]

Looks like MIG. Not the best, but it does the trick for cheap steel

mig welded. i think (hope) it will work, wont file or sand the welds so theres plenty of material.

I've migged a few frames together. Filed the welds on the one to make it pretty, so long as the joints are mitred nice and you've achieved good penetration there's nothing to worry about.

Got anybody also experience with arc welding frames? Its not really suitable for these purposes?[URL="http://www.dict.cc/englisch-deutsch/welding.html"][/URL]

Not really. Too much heat. You could if you had solid bar instead of 1mm wall tubes.

It's rattier now.

Malvern Star by Verbs & Nouns, on Flickr

It lives on!

^^ fan of both of those. good work SadR

That blue one's an absolute banger!