"Slipping" front brake

Hey!

I just installed a front brake on my Peugeot yesterday and had a real problem with it actually slowing me down.
I used the old Weinmann brake that was originally on the bike, but bought new Shimano brake-pads.

The wire is tight and the lever works and only goes about 1/4 of the way to the bars before I can't pull it anymore, and the bike still rolls. I can even overpower the brake by keeping the lever in and pushing the front wheel with my hand.

I had to use both of my hands to get that extra pull for the brake to really bite.
Any suggestions on what the problem might be? =

steel rims ? long pull levers for short pull calipers ?

I think the rims are alu, they're Weinmann LP18s.

Might be, the levers are some noname-mtb levers I got at a cheapo-mechanics-store. Got some other levers as well, from a bike store, so maybe I should try those out.

But it's weird, I've never had this problem with my old mountain bike before..

I have a brake like that and it's shit TBH. What brake lever are you using?

It's some noname thing, I'm not quite sure. I couldn't find MTB-style levers to fit my drop bars (all the levers were too small) so I had to forcefulle "open up" the lever-mount (if that's what it's called?) and use a longer screw.
I didn't know if it'd work so that's why I used the cheapo lever, in case I totally screwed it up.
The good bike-shop lever I have is Tektro.

I seems that it is the problem of short pull brake/long pull lever, since the "symptoms" are the same.
Found this just now (http://www.jensonusa.com/store/product/BL309A02-Tektro+319Ac+Rh+Bmx+Short+Pull+Lever.aspx) and it looks decent enough to have on my bars. I'll see if I can get a hold of it here in Oslo..

Brake cables rusty inside outer cover?

Try spraying lots of WD40 in from both ends or replace them?

MTB levers aren't meant to work on road brakes, if that's what you're saying, its a different pull than the road levers, same as road levers on V brakes aren't too good, and need an adaptor to make work effectively- and I've recently been there :-((((((

Also, if they are old weinmann single pivot calipers, and especially if they are longish drop then the flex in the arms will be hideous. Brake technology has moved on a way since then - a relatively modest investment in a modern dual pivot caliper will deliver a vastly superior brake set-up.

AUSHTA
http://www.sheldonbrown.com/gloss_bo-z.html
Wrong ratio

Zippie: the cable is brand new, bought it just some days ago!

I've accepted the fact that the brake is old and "outdated". I thought I might keep it original, but I don't care now, I just want to ride.
I found this brake at VeloSolo, it's cheap and I trust VeloSolo when they say it's good:
http://cgi.ebay.com/BN-Shimano-Exage-SINGLE-Front-BRAKE-Caliper-FIXED-fixie_W0QQitemZ380121496825QQihZ025QQcategoryZ27949QQcmdZViewItem

They also have Dirt Harry-levers which I might pick up as well, also because they recommend it. I think my bars will be too fat for the lever though, I'll measure it before I buy..

I just hope this will work finally, I'm very bad at stopping breakless.

Freezing: Thanks for the link, SB is the king! I didn't even think about checking out his explanation for this.