I'm looking at getting a Mongoose Massif which I believe is a 2003 model. It is dually with a sid rear shock and Duke front. I checked some tech documents on the shock and it said max air pressure was 250. How does that translate to rider weight. Does that mean a max rider weight of 250. Also I think I remember something about a blow off, does that mean that the shock will blow out air before the seals blow?