Cheap and good MTB cycles are equally good for the purpose of calorie burning and belly fat reduction. In India except Firefox Cycles, other bike makers like Avon Bicycles, BSA Cycles (Hercules Bicycles), Atlas Bicycles, Hero Bicycles, are a few examples of bicycle manufacturers who make cheapest bicycles in the world with reasonably good qualty. They use steel instead of alloy to manufacture a bike. These companies' bikes are value for money. Most bikes in this category are priced between approximately Rs. 4000 to Rs. 6000. What bicycle worth this amount gives you in return is precious health which is a lifelong investment. In this range some bicycle models are designed similar to mountain bikes.
Now you decide: which bike gives you health: Hero Cycle or Hero Honda?
If you have any experience of these models please write a review through the comment section at the bottom. Hero bicycle specifications and prices are as per the Hero Cycles website.
While riding a bike for exercise, remember bike safety also.