BMX - Just curious...coming from MTB+road biking and all

I went to ride one of my friend's BMX bikes the other day and I noticed a few differences from my MTB.

For one thing...why is the bike so freakin' heavy!? I tried to bunny hop it, and almost gave myself a hernia! its half the size of my huffy, but weighs twice as much! Is there freakin' lead in the tubes? The guy whose bike I rode said he put a several hundred into the bike, so I don't think it is cheap...

Also, why do the brakes suck? I think they stopped using u-brakes on MTBs becuase they didn't work. wouldn't V's make more sense? like somehting that will at least lock up the wheels?

I went to my LBS and looked at some more BMX bikes, and they were heavy and had bad brakes too.

Honestly, this isn't a total bash on BMX bikes, but seriously, what are the reasons for the crummy brakes? Also, are there BMX bikes under 30 pounds?

If I was to buy a BMX for under 300, would I just get a POS like I would get for a road bike or MTB?

BMX bikes are heavy for several reasons. One thing is for the most part they use thick walled 4130 frames. Equally as well for the forks. The cranks if they are 3 piece are like the frames 4130 cro-mo. most good bikes will use thick triple walled rims and 14mm axles in beefed up hubs. Bars are equal to specs of frame and fork for the most part.
To put it all short they are made around the idea to hold up to being jumped and trashed in the street, ramping, grinding etc. So with that you cannot have a buch of wimpy lightweight parts and expect it to hold up to this type of abuse. As far as the brakes go well some simple setup work will fix any problems they initially have.
To answer your question, NO.

some U-brakes work well, like the odessy evolver and the dia-comp 990, i've ever heard that the dia-tech brakes are failry decent as well. tektros will never work as well as dialed 990s, they flex too much. V-brakes...on a bmx bike...i've seen them on racing bikes, but i think for the most part, due to brake positioning (some companies put the brakes down on the chainstays, and others put them upside-down on the seat stays) V-brakes would not fare very well. also they look stupid. i use dia-comp 990s mounted on the chainstays and as long as they're dialed, i don't have problems. i pull abubacas, and fufanus and i hardly ever worry about whether my brakes are going to fail. another issue as far as braking is concerned is what type of rim is being used. if it's a chrome rim, with decent U brakes, everything works fine, if it's a black or silver rim, there's gonna be trouble. the V-brakes on my trials bike on the other hand...i'll just say i'd rather have 990s or hydraulics and leave it at that.

BMX bikes that are under 30lbs are race bikes that will not hold up for very long under street conditions, because they're either aluminum or thin-walled steel.

oh yeah, bunnyhopping on a BMX bike isn't about how strong you are, or how heavy the bike is. it's about the geometry of the frame and knowing how to use it...leverage is your friend.

and yes, phatman, you will get a POS for under 300, or you could get a decent frame for around $270.