Being Captain of the ship has rewards and head aches.
I worked full time at my day job for 5 years while slowly building inventory and clients.
I worked 12-16 hours a day, 7 days a week.
Of course I had no money to start a business with so everything I made I invested back into the business.
So, when I quit my day job I was already rolling.
I understand from most of the bike shops in our area that new bike sales are dead.
Even repair isn't doing all that well, although that may be just a local problem.
My advice is be prepared to work hard and for many long hours.
Don't make a few bucks and then spend, spend, spend.
Watch all your expenses carefully, keep track of where the money is being made and focus on that aspect of your business (Records are everything).
Be good to your customers and learn how to say no without giving offense.
Train your employees carefully and pay them well.
Remember, it's not what you do, it's what you get done