Runflat CBR is a new product so has been subject to a very rigorous testing regime.

At the design stage each Runflat CBR type is assessed through Finite Element Analysis (FEA) and Failure Mode and Effect Analysis (FMEA), then static laboratory tested, endurance and longevity tested, followed by track testing, environmental and durability trials.

FEA is used at the design stage to assesses overall strength and weight carrying capacity, shock resistance, cornering load and kerb strike effects and beadlock effect and forces.

Once the design of each Runflat CBR model has been adjusted in line with the findings of FEA and FMEA testing, prototype components are manufactured in order to continue to static trials, which are carried out at Boeing’s Advanced Manufacturing Research Centre. Strength, weight capacity, shock absorption, kerb strike and beadlock force and effect are measured.

Results are then analysed and components are fine-tuned and re-tested until the required parameters are met.

At this stage, assembled wheel, tyre and runflat units are longevity tested by one of the UK’s leading OEM wheel manufacturers. Continuous test runs simulating 10,000 km at 90mph (144kph) followed by brake and acceleration simulations, prior to stripping down and inspection.

Further trials Runflat CBR has passed include laboratory impact testing to ensure sufficient shock absorption to help protect vehicle suspension and to resist runflat damage during off-road runflat.

In addition to validation trials carried out at IDIADA, Spain and Bruntingthorpe, UK, further performance trials are to be carried out by MIRA. Also, military vehicle OEMs and other bodies throughout 2018. These results will be published once completed.

Runflat CBR was designed with the intention to provide all-tyres-down drivability on the normal single piece drop-centre wheel and to significantly increase performance in runflat speeds and distance over any current system. Better drivability, to include evasive tactical driving and off-road abilities with one or all tyres down, was another primary target.

Runflat CBR Off-Road has passed in-house testing exceeding FINABEL A.20A 150km with all 4 tyres deflated and high speed runflat and slalom trials have met targets that we believe exceeds any other runflat insert previously tested. These tests include ‘escape’ and figure 8 g-force trials and rig based impact testing.

Tested at IDIADA, Tarragona, Spain, in February 2018. Distance recorded 251.19km. Tests were concluded at the expiry of track time, with runflats still operational (tyres were re-inflated following each trial)
Note; Applus IDIADA test facility is the most comprehensive independent proving ground in Europe.

Further performance trials are to be carried out by MIRA and military vehicle OEMs throughout 2018. These results will be published once completed.

A specially extended variation of this test was carried out at Bruntingthorpe Proving Ground, UK, on 8th August 2017.

Variations to the standard FINABEL test included:

• All tests were carried out with all 4 tyres deflated.
• Both tarmac and off-road trials were carried out on the same set of tyres and runflat CBR inserts (FINABEL allows for a different set for each trial).
• Tarmac tests covered 150km
• Both tarmac and off-road tests were carried out at higher speeds than defined by FINABEL.

Vehicle: Toyota Land Cruiser, laden to maximum gross weight.
Wheels: Standard Toyota 17×7.5
Tyres: Standard size; 265/65 R17 Michelin.
Runflat insert: Runflat CBR Off-Road
Ambient temperature 16°C

Test conducted with all 4 tyres deflated
Two hours were completed at an average of 41kph (Finabel requirement is 30kph).
Tyre temperature at start of trials; 16°C
Tyre temperature at end of trial: No change.

Run Flat Systems Ltd is currently working with military organisations and vehicle manufacturers with the intention to continue developing a range of products designed to meet far more exacting requirements than traditionally expected for any runflat insert for the single piece drop-centre wheel.

Verified at Bruntingthorpe Proving Ground, UK; excellent high-speed control through cornering, steering, traction and braking – with all tyres deflated.

Test conducted with all 4 tyres deflated
Vehicle was taken to 90mph (144kph). Total distance 1.88 miles (3km).
Then immediately driven for 22km at 40mph (64kph). Finabel requests 31.25mph (50kph)
Followed by 176km (110 miles) at 25mph (40kph). Finabel requires 175km at 25kph.
Tyre temperature at start of trials 16°C
Tyre temperature and end of trial 25°C

Tyres and runflats were inspected after these trials. Tyres were unmarked and looked ‘as new’. Runflats showed a small amount of wear on the anti-friction roller, but were still serviceable. The main body of the runflat showed minimal wear and these components were used again on subsequent trial.