Crash means a major or critical dip which can cause death of a curreny. I think you mean a dip, yes we can expect a dip but not sure, at first i was expecting that the price will increase after fork but soon i realized that the price is pretty much high now before fork so it is possible that after fork the whales will try to cash out from the market and there could be a fall of price. BTW this is just a prediction and as we know that bitcoin is unpredictable.