Replying to 270 off rails- how?

So i've finally started doing rails harder than straight ones so i decided to start trying 270 off on the ones i get all the time now.

But when i tried, i didnt know if i actually had to pop, or let myself 'slide' off if you know what i mean... I always found myself going too backwards like when i was starting my first 360s a few years ago(now i can do them).

Any help?

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If you saw two guys named Hambone and Flippy, which one would you think liked dolphins the most? I'd say Flippy, wouldn't you? You'd be wrong, though. It's Hambone.