I drink coffee all morning with my last cup about 11 a.m. I ride on weekends and drink two big mugs of coffee before my pre-ride fruit and protein smoothie. I have no idea if it helps my riding, but it's the way I like to start each day. I don't have jitters or other side effects, or at least none that I know of.

Caffeine Levels in coffee, et al . . .

COFFEE CAFFEINE (mg)
Brewed, drip method (6 oz.) 115
Brewed, percolator method (6 oz.) 80
Instant, one rounded teaspoon 65
Flavored, regular & sugar-free (6 oz.) 25-75
Espresso (1.5 to 2 oz.) 100
Decaffeinated (6 oz.) 2
Decaffeinated Espresso (6 oz.) 5

OTHER CAFFEINE (mg)
Tea, brewed (6 oz.) 35
Mountain Dew (12 oz.) 55
Baking chocolate, unsweetened (1 oz.) 60
Chocolate ice cream (1/2 cup) 2
Excedrin (per tablet) 65
Excedrin PM (per tablet) 0
No Doz, regular (per tablet) 100
No Doz, maximum (per tablet) 200

Source: Men's Fitness June 2000