Go to Vermilion city and go into the Pokemon fan club talk to the chairman he will ask you to listen to his story say yes then he will talk about his rapidash after he's done he will give you a bike voucher go to Cerulean city and go into the bike shop show the voucher to the cashier to receive a Bicycle.
There is not a bike voucher in Pokemon sapphire
You have to have the three starters to get a bike at the pokemon fan club
In Pokemon HeartGold (And Pokemon SoulSilver) The bike road is on Route 17 in the Kanto region.
By bike
The Bike Shop...........
You get a bike in ramion city
you need to go to Mauville to get a bike an Acro bike or a Match bike
heres only a bike no acro bike or mach bike
get the bike ticket and bring it to the bike shop and you will receive a free bike
Talk to the guy in the pokemon fan club at Virdian city. He will give you a bike voucher and then cash it in at the bike store
In cerulean city (You will need to get the Bike Voucher from the Pokemon Fan Club in Vermillion before being about to get a Bike)
the Pokemon fan club in vermilion has a guy that gives you a bike voucher