Honestly, if you want to take the bike on the loan, it will be calculated on a flat rate. Stop dreaming that somebody is going to change this. if they quote 1% interest per year, it will become 2% on the total loan amount for 2 years and not the reducing amount. The bank is not cheating anyone. If you think they are, then don't take the loan from them, because no one is forcing it down your throat. Besides, the bank is never going to give you the loan, till you agree and sign for all the calculations. That is certainly not called cheating. Also, they tell you the exact amount you need to pay, your interest and your EMI. That is also not cheating.
Solution: You want to take a bike on a loan, then check banks calculation, if you are not satisfied, don't take the loan, nothing more simpler than that! If you still think they are cheating, then you are only letting them do so, coz they always tell you all the details and exact payments.
PS: Private banks and other laws in the country have their own problems. If you think something is misused, don't buy it, or report it!
But why should they charge at a flat rate of 18% when they charge all other loans ex. four wheeler loans at a reducing rate.
Because bikes loans are bike loans and car loans are car loans!