HI, i don't know anything about pro-jump and don't actualy have a pair i've just this evening been trawling through the forum to learn a bit about it/tem all before i buy a pair, however, having said all that i am an engineer and the white line you've talked about sounds like a stress fracture or the beginings of one.
When you bend a piece of metal past its elastic limit, white lines will form eminating from the highest point of stress. The fact that you have said that this line runs through two bolt holes enforces my concern, although a circular hole is the best way of avoiding concentrated stress it does however localise stress to some degree, especialy if there is a nick/cut/wear around the hole which may produce a point of stress.
I do not know the position of this line nor how much stress is placed apon this point of the pro-jump and as i have not seen it in person i can not say for sure and i may be completely wrong, i hope i am, but i would advise caution and would recomend that you take it to any decent engineering company and ask them to have a look at it. I can imagine a failure at high speed or whilst landing a large jump could prove very painfull.
The most likely cause of a stress fracture i would have thpought is that the gear has been overloaded as it will have been designed to take into acount the stresses involved under normal use.
I hope i haven't put the fighteners on you, i am most probably wrong and pro-jump's are i'm sure designed and manufactured to extremely high standards, i just wanted to pass on a concern.
Do e-mail me with pictures and i will try and give a more informed opinion, my e-mail is afclewis@yahoo.com
