Perhaps the rest of your life? I started out on MTB's and switched. I raced from day one on a 20" with clips and after a year I took them off and never went back. If your track is wide open with big stuff, maybe being clipped in would be a good idea, but if its tight (like indoor) I wouldn't bother, you won't see much benifit.
I never raced with clips (Cruisers26-30/30-34. Gave up racing about 3 years ago). I never felt that I needed to. I could keep up and/or win without them. I guess it's just a comfort thing. Many folks swear by them and insist that they are faster.
How long should you wait? That's up to you. Why do you think you need them?
Honestly, its all preference. Its like asking what tires/bars/stem length/many others should you run... If you know someone who might have a set of clips/shoes that are your size, ask if you can try them out for a run or two... see if you like them or not.
more experience is why they pull from you there, not the clips. i can gain or pull on almost anybody in a roller section. you will eventually learn how and when to adjust your cadence to constantly pedal around the track...
I personally think that clips and BMX racing don't mix and is one of the things wrong w/ racing these days. Sew-up tires for the little guys is one thing but putting a 6 novice in clips just seems wrong to me. As bad as a dog-piss air looks it's saved my ass a bunch of times on jumps and it seems you don't get that chance when clipped in.
hahahaha, dog piss air, great visual, I can see it exactly in my head in the scramble to recover.
I've never ridden clipless on a bmx, nor 24 cruiser, so I shouldn't really speak here.... but from my experience with clipless on other bikes, I could see how they may help you lay down the power with a more balanced pedal stroke, with the pulling up while pushing down at the same time keeping the bike a bit more calm when you're spinnin' your jazz off over some rollers... but like WCH said, not much replacement for experience.
And yeah, putting a child on clipless peds is just feeding bad form as it grows from the start! The kid could be handicapped for life without knowing what a real bike should be ridden like!
Before they went to a random gate, if you had good timing the difference was less pronounced then it is now. Clips are really an advantage over the first three full rotations out of the gate, after that they are negligble.
Speaking of kids and clips... One night at the track, there was a little kid, maybe 7-8 years old, riding clips. I noticed he was riding into the side of the berms and laying the bike (and himself) over on the uphill side. Then he would yell for one of his little friends or his Dad to come and pop his foot out of the cleats. If nobody was around he would take his foot out of his shoe to get off the bike. I helped him once, it wasn't that the release was too tight. The kid just had no clue how to unclip.
WTF was his Dad thinking? This is OK? I felt bad for the kid and Dad deserved a kick in the nuts.
This is all about timing. You power wheelie over rollers and if you do it to late or to early it will feel really awkward. The key is practicing it, but I pedal hard at a roller, pull up and hammer over it. Tons of speed, especially on the back side where lots of people will just be pumping. This will definitely make you faster.
Now if your talking about in a rythm section, get your pump and jump on. If you know how to ride flats there should be no problem with that.
Just as a side note. I think for some DH racing there is a benifit of clips. Really rough courses where your feet won't stay on the pedals can make for bad situations. Or on fixies, but thats another story.