Springs do seem hard when you start
A couple of questions
How fit are you (be honest)
Have you ever bocked before
How determind are you
First one to give you an idea
In the old springs I use 114 to 117 and when unfit I can't bottom them When fit I wish they made 130's
New springs I use 107 and 112 neither of which I cam bottom but I get much more height
Second one
If you are hurting your back there are 2 reasons
1 you are not fit enough Bock more but gently to build condition
2 you are leaning forward/looking down or bending your knees during the compression bit (when the spring bends) this is technique get to some meets and people will shout at you to get you straight
3 (yes I know I said 2
) you have a bad back go and see a chiropractor
Third one
It takes a lot of practice and time to build up the right technique and enough muscle to do the high stuff
Most people get to the running/jumping and doing a few tricks then slow down (due to fear a lot of the time
)
Getting lots of height and big tricks takes time and hard work so stick at it and in a few months it will come
The best bit of advice I can give anyone is to go to meets (what ever level you are) you will learn much faster be safer and enjoy it more
Jason