Tyre sizes

[Woody4567]

Hi all, recently had front tyres changed during a service. Got loads of vibration through steering wheel at 60 mph. Took it back and they were rebalanced. Now it's happening at 70 mph. Think I remember the guy saying that they'd put bigger tyres on the front, but denied that when I took it back. What's the consensus, same size all round or not? Any thoughts on why the vibration is occurring, didn't happen before new tyres. Thanks

[Bob]

Many of us run with the same size tyres all round, that shouldn't cause any problems.

[Northern Bongolow]

does the bongo have alloys on, maybe with spigot rings fitted. or steel wheels.