Can someone explain bump stops to me. I dont understand why after lifting 2-3" bump stops have to be used. Isnt the point to get more travel not just height?

 

The bump stops limit the up travel preventing over compression of the springs and rubbing.

 

as mentioned, you want bump stop extensions as they will help prevent the over compression of your coils. a lot of people also use them to help prevent rubbing at a full stuff.

 

More down-travel is good. Up-travel, as noted, puts the tires through the fenders and can cause over-compression of the coils. Some coils are designed to survive over-compression, some aren't, just depends on the coils and the mfg.
- (I was in contact with a tech supervisor for OME concerning this, who referred me to a senior design engineer down in aussie-land. He quoted some 'solid stress MPa' numbers, and said that OME coils will not be harmed by over-compression, but suggested adding bumpstops anyway.)