BB & crankset question

time for some recursive forum navigation...

[QUOTE=highboy_coupe;1496578]
Whats the deal with BMX BB + cranks, my tiny mind says if it's a Euro BB then the bearings/cups and crank axle will fit into a 68mm MTB BB shell, even allowing spacing of the chainring? So it just a matter of staying away from Mid and Standard BBs, Or is there some other magic going on?
I have a 107mm square taper in at the minute, and chainline issues mean it's going to have to stay that length, any ideas on spacing a coaster hub sprocket out?

[QUOTE=propeller;692198]there may be a thread about this that i cant find I HAVE SEARCHED !
if there is please link me to it.
if not, what do you guys think about having bmx crank arms and stuff on fixed/single speed bike? or is it just fashionable to have it?

[QUOTE=mdizzle;1124764]I used the search and found some things, but i need some advice from the ex/current BMXers out there.
I live in Brasil, and the availability of any kind of fixed gear/track frame is not that good, so to counter this i have collaborated with a BMX frame builder to produce a prototype frame.We used a track frame for the template, but have made it from 4130, it weighs in at 2kgs.....the only problem is that it has a mid sized bb.
This means i can only use BMX cranks, apart from the chainring pinch bolt unscrewing and the obvious weight dis-advantages, what other problems will i encounter using a BMX crankset?
As i have said this is a prototype frame, and anu ones that go into production will have a standard threaded bb, we just built with what we had available....
Thanks for any help......

[QUOTE=vinylvillain;1124774]http://www.londonfgss.com/thread21907.html

I am sure i heard Profile are making a Fixed specific crank now?
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There's loads of info in other threads about this, but yeh your basically right. BMX cranks are completely adjustable (profile 19mm / primo 22mm). You can change the shell width (cut the tube spacer) and chainline to suit anything.
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