the brass is an entry level dirt jump bike and it will do the job. Weight is pretty much not important. Technique is what gets you in the air not a light bike. Just go to the trails and keep practicing. It takes time to get good at jumping and dont forget to help maintain the jumps they dont build themselves. The builders in anns and enniskerry will be glad of some help keeping there trails in good repair. Save your money and keep riding the bike you have for now. Once youve got a bit of skills it will make it easier for you to get a new bike as you will have more of an idea what your looking for in a dirt jump bike. They all look the same but different length top tubes, seat stays etc will change how the bike feels. You will understand this better once youve spent some time on your existing bike and are more aware of its short comings etc. Good brands are the like of ns, blackmarket, dmr, identity but theres no need to go and shell out a load of cash on a bike as its not gonna make it easier over night. Its all about spending time on the bike you have.