heh, dogs just love things that move fast. either that, or they they hate them. both ways, you can expect your dog to chase stuff, so try training it to just stay with you and not fly off somewhere. there are dog camps for stuff like that.
Its a prey drive if something moves CHASE IT thats how a dogs mind works.
Also what dutchman said if you block this behaviour with a correction and exert your dominance (put your foot down...so to speak) then he should learn.
It is your dog - or rather you that is at fault, not the person or people riding the bikes.
You just don't allow your dog to chase bikes --- and he doesn't go offlead all the time there is the opportunity for him to do so.
For crikey's sake. Can you imagine what commotion there would be if I was walking four rotties and they decided to chase a bike. I'd have the police on my doorstep.
You reprimand your dog and tell him to LEAVE IT.
Have I got the wrong end of the stick here --- lol ..
No. Bike riding is excellent exercise for your dog. And, since not alot of dogs can ride a bike, you could probably enter him in a circus or sideshow and charge a fee.
You could put him on T.V. on the Animal Talent Show and maybe win a prize.
I'm sure lots of people would pay to see a dog riding a bike with a clown for an owner!
Have Fun!
EDIT: One more thing - you should learn how to spell TIRES!
EDIT: My answer was tongue-in-cheek since the asker is saying the dog rides the bike - get it? Only a few of you did.