When one of your old riding jackets or a favorite pair of pants starts to get old and worn out, you have to eventually come to the realization that you've either got to make some repairs to it or throw it away. The second option can be sad if you've had the jacket for years and worn it to many different events. The iron on patches you have on it may show a history of your motorcycle career. Sometimes, a few more patches on rips and tears can be a way of prolonging the jacket's life but sometimes there's just no saving the item.
Obviously, if the rip is small enough, you may not even need to patch it. This is especially true if it doesn't go all the way through the material. You could possibly sew it up or put a little bit of liquid adhesive on it to glue the edges of the rip down. If it does go all the way through the jacket, you could always put a patch on the inside. You can still show off the patch if it's on the inside front. In fact, that might be the best place for a few of the really offensive motorcycle patches out there.
For pants, you almost always have to patch up the major rips and tears. Sure, you can wear them with holes in the knees, and it's even fashionable to do so, but it's not the safest for riding. You want your pants to protect you in case you go skidding across the road. If the tear is on the knee or other area that needs to be flexible, though, a patch might not work. In that case, you may have to accept that those pants have seen their last days.