Tyres

A special tool is needed to quickly install a tyre band, otherwise it’s a labour-intensive time-consuming hassle

Tyre bands are no longer an interesting gimmick. What's a tyre band? It's a metal band fitted inside a rim to prevent the tyre from coming off the rim in the event a blow-out or total tyre failure. And why has this been elevated above gimmick status? Two factors are driving demand for this product, namely accelerating crime and deteriorating road conditions. Any vehicle stuck at the roadside appears to be a target for the picking and the time of day, especially the dark hours, aggravate the possibility of personal injury as well. Changing a wheel- if you can and if you have a spare - means being stuck on the road and in SA today there are some places you just don't want to stop. In other words fleet managers, how flat can you afford to be? Dave Scott reports

I have friends who have been shot or mugged at the side of the road. Especially if you are female you do not want to find yourself stranded with a flat wheel where the car cannot be driven on a tyre that has come off the rim. Enter SSR tyre technology - the 'Self Supporting Run-flat' tyre. SSR is now standard on all BMW cars and pressure sensors are part of the kit as something has to caution a driver on SSR tyres that pressure has been lost, otherwise total loss of pressure on SSR tyres could lead to catastrophic failure without warning. Website info indicates that a SSR tyre can withstand around 50km at 80kph. One sure thing is that total pressure loss on a standard tyre is felt immediately and if it's a steering tyre then total loss of steering control and direction when the tyre comes off the rim - not unless of course it's equipped with a tyre band to keep it on the rim.

The SSR debate
The problem with SSR technology is that it costs. SSR tyres are priced around 15-20% more than a standard tyre, and then add in one pressure sensor per tyre at approximately R2000 - the essential Tyre Pressure Monitoring System, or TPMS, that adds another acronym to the tyre Tower of Babel. This all means that 4 rims, tyres and sensors on a car quickly total a R30000 investment. Apart from a harder, more-sporty ride, SSR tyres cannot be repaired after being driven on when deflated and a vehicle owner could be in for a massive replacement surprise. And the final downside is that tyre fitment centres are reported to need a R20000 investment in special tools to handle SSR tyres - not everyone has this, especially in remote areas where a puncture may occur. Leeugamka, between Laingsburg and Beaufort West, is a good example of where not to experience tyre failure.

The great SSR debate has clearly not been thought through and vehicle buyers are really not aware of the implications when buying new cars equipped with this technology. It's great stuff but it has a serious cost of ownership implication that will not necessarily be found in a budgeted maintenance plan.

Heavy truck tyres are not in line for commercially-viable SSR technology yet or the foreseeable future. Apart from the cost implications, the load factors that truck tyres must endure - up to 3750kg per tyre at 850kPa - make SSR design requirements very difficult. TPMS pressure sensor technology is very much available for trucks and as the price of this equipment drops with increasing demand and volume it could be as universal as ABS brakes in the future.
 

This is a typical modern tyre band ready for installation into the well of a passenger car rim - you can travel at 60kph for around 20km depending on the road surface on a flat tyre with this installed because it prevents a tyre from coming off the rim. The tyre will be destroyed but the rim should not be damaged and you can reach a safe place for a spare wheel change – if you have one!

Spare wheel - what's that?
Spare wheels are a soft crime target. Just look at all the bakkies on SA road with a dangling chain where a spare wheel is meant to be housed under the rear tailgate. Where a van body is fitted the spare is most often carried loose inside the van - it also disappears from here. South Africa's bakkies are particularly vulnerable to a run-flat scenario as the tyres are not SSR design and the spare wheel is very often under-pressure - if it's there at all. 

Cars are being sold into the market without a spare wheel - certain French car models for example - where they are not equipped with SSR tyres and offer a 'tyre-goo' inflation kit in place of the spare. The problem with 'tyre-goo' is that it cannot repair a run-flat blow-out and will only temporarily seal a leak. The goo does not prevent a tyre from coming off a rim. It's easy to understand why sales people selling cars not equipped with spare wheels avoid this subject as the absence of a spare wheel, no SSR tyres and a bottle of goo could be a total customer switch-off! 

When it comes to trucks the 'goo-route' appears to be exhausted. Inserting the stuff to prevent leaks has not been a market success story and the pressure required to re-inflate a truck tyre takes a very large bottle. Large truck fleets operate without spare wheels and have an emergency recovery plan in place should they experience a run-flat. 
 

Ian Flint – National Sales & Marketing Manager for Protectall – "It’s time to openly discuss the risks that a driver faces on the road when a tyre runs flat. Sales people are selling cars and not telling their clients that it has no spare wheel and what the implications of this may be. Some trucks are prime crime targets because of their very highrated value cargo. Disabling a truck through a tyre failure that comes off the rim is the easiest way to plunder the cargo. Crime and deteriorating road surfaces make tyre integrity a real issue when a run-flat occurs."

Tyre bands - an affordable option?
According to informed sources the development of the tyre band has its roots in the Irish 'troubles'. The IRA would shoot out British Army tyres that collapsed in the rim and made the vehicle un-driveable. In a combat situation army vehicles equipped with tyre band could still be driven even though the tyres were beyond repair. 

Off-road vehicles that deflate tyres to travel at low speeds in loose underfoot conditions will find that tyre bands will minimise the chance of a tyre bead from slipping off the rim into the rim well. Total tyre deflation in off-road areas is an extremely aggravating situation.

A modern tyre band can accommodate sensors (TPMS) if required and has matured in design. It's now available in corrosion-free T5 hardness aluminium and at 250gm mass it becomes part of the rim and does not interfere with wheel balancing. On a truck one is looking at an investment of R2000 plus VAT to equip a steering axle with tyre bands - run flat countermeasures are not as serious an issue on a rear axle, dual-drive tyre set. 

ABS may prevent wheel lock-up and retain vehicle steer-ability but if a steering tyre has left the rim then even ABS doesn't save the day. That's why bus fleets such as PUTCO on long-distance operations and Gauteng Coaches are equipping buses with tyre bands. And when it comes to dangerous goods, companies such as Unitrans Fuel & Chemical have standardised on tyre bands for steering axle tyres. OILKOL, an 'ISO 14001 Certified Collector' of used oil even state on their brochures that they are fitting tyre bands because they are 'Serious about your risk and the environment'

Conclusion
You cannot ignore the fact that you may experience a puncture. If you are running a fleet then the probability has a multiplying effect and one has to commit some form of policy to paper as to how a run-flat situation will be handled. When call comes in from the field to deal with a run-flat there must be a procedure to avoid a crisis. Here are a few questions - 

• Do we buy vehicles for operating field staff that have no spare wheel?

• Do drivers of fleet cars with SSR tyres fully understand the implications of how to handle a run-flat scenario - speed and distance limitations

• Should we consider tyre bands for the light vehicle fleet - and if so, which vehicles?

• Should all female staff cars be equipped with tyre bands - is this not a discriminatory practice?

• Do people know how to treat a car equipped with tyre bands - distance and speed limitations?

• Should we consider tyre bands for truck steering axles - which trucks, routes and goods types would drive this decision? 

• Are there some routes that expose our vehicles and goods to risk and tyre bands should be fitted to all vehicles operating in these conditions?

• What is our spare wheel policy for the different fleet vehicles - is it practical?

• Do we audit what is happening to the spare wheels in our fleet and have we maintained detailed records on punctures and run-flats?

• Is our run-flat policy well considered against the risks we run?

It all raises more questions than answers - be prepared to take a stand on the issues. How flat can you afford to be?