any amount of exercise will help you lose weight, but it needs to be paired with a proper diet. The simple fact is that if you burn more calories than you take in, you lose weight. A 24 mile ride can help you do that, but there is a lot more to it than the distance you ride. The intensity that you ride matters a lot as well. Your best bet is to vary your rides. Do some longer slower ones, do some shorter harder ones, and definitely do some sprint intervals if weight loss is your goal. How many days a week are you trying to ride?
Weight loss is a matter of changing your food input and your excercise level from your current situation. If you were only riding 10 miles, then a 24 mile ride is a big increase and the sort of change that can help you lose weight.
Over the past couple of years I've doubled my mileage and improved my diet and lost some weight. It is surprising how little food one really needs to eat....I would suggest that food/eating is now more an entertainment activity for most people
Can anyone suggest a road cycle workout for losing weight??
Ride a lot.
While you will burn more calories doing hard efforts, you can't keep them up for long. For example a hard hour for me burns 900 calories, but then I am done, or wish to be. While I can ride at 600 calories/hr for five hours.
As long as you have the time and inclination, the more riding you can do, the better.