MGB GT WIRE WHEELS
Q I have a 1969 MGB GT and am in the process of purchasing and fitting a new set of tyres. My initial enquiries have led me to believe that the wire wheels cannot be balanced on the modern wheel balancer equipment that most garages now use. I have been advised that the wheels should be balanced using a system that can balance the wheels whilst they are fitted to the car, but I am having trouble finding a garage near me that can perform this type of balancing. Is it correct that this is the only way to balance wire wheels? Henry Wyper
A The short answer is no – although the on-vehicle balancing has always been recommended for wire wheels, this is not the only way it can be done. There are now a few companies who can supply a kit which will fit on the modern wheel balancer to accept the wire wheels. Specialists such as Longstone Tyres who cater to many pre-war cars will also have the equipment needed to balance wire wheels. The biggest problem with the modern machines is that they normally allow the back of the rim to sit on the flat bed of the machine, which prevents the wire wheel from centring correctly. This is because the universal cone supplied with the machines as standard is not suitable for the wire wheels.
As you are changing the tyres, there are a few points which are always worth checking on wire wheels before carrying out the tyre replacement. You should clean the centre splines on both the wheels and the hubs and check for any wear. Worn splines on either the wheel or the hub are one of the biggest causes of vibration when driving. If wear is detected, then the hubs and the wheels will need replacing, because once wear has begun it will invariable cause problems and get worse.
Once the wheels and hubs are thoroughly cleaned, the wheel should be refitted and the runout at the hub checked using a DTI (dial gauge) – the maximum run out on the MGB is around 1.4mm. Any more than this and the wheel will need to be straightened. Providing all the above criteria are met, then you can have the new tyres fitted and balanced.