350x frames breaking

[ride.redatc350x]

I recently discovered a crack in my 85' 350x frame.
I have a parts bike for my 350x, and so I took my spare frame to get powder coated.
I read on a thread here that a 350x frame cracking is not abnormal.
if this is so, why?

[Xfile]

I have never owned a 350X, but it seems just about every sport/race trike has its weak spots. TRI Z's have weak foot peg mounts for example. There are people here who know how to properly gusset a 350X frame to prevent this problem but Im not one of them. Someone with knowledge on this may chime in.

[RapidRick]

This will get you started I think

http://www.3wheelerworld.com/showthread.php/137374-1985-350X-frame-repair-gussets?highlight=gusset