OP, believe it or not

I used to ride "gas-pipe-quality" hybrid bike, its made from cheap grades alloy

Its strong and durable, I use it as beater bike but there problems . . .

Whenever I try to sprint hard or dash from zero at red-light, my chain will occasionally "slippage", its happened, I almost fall because of this

I try to check chainset, drivetain, chain, all NORMAL, I even decided to throw some money and change new whole drivetain

Problems still exist, everytime I sprint out of saddle so hard, its slipping so I am mad

I dunno what the heck wrong until I have someone check it for me, he told me "this bike is broke, the frame is twist like ****, its also too flex, you better buy new one that stiffer"

He explains to me why is that, he do hard out of saddle and told me to look at chainstay, I don't believe it! my frame is flex so much!

Then he told me "you better not sprint hard, if you loved to do sprint, buy a proper bike for the cause, buy good one Chromoly or good grades aluminum instead of this stupid gas-pipe-steel bike"

That's it, your frame maybe . . . too weak for your