Fred Henderson assesses the Endurance Rallying tyre situtation
Dear All,
I don't know whether to feel frustrated or whether it is just disappointment at the way the tyre situation is evolving in relation to Endurance Rallying. After the demise of Colway I was asked to help to find a suitable replacement tyre leading up to this year's Lombard Rally. I went round to all of the available manufacturers and remoulders and it was immediately obvious that getting a replacement tyre with the same features of a Colway was going to be difficult.
The parameters were simple; minimum damage of the road surface, suitable for tarmac and gravel, possessed of good puncture resistance and, most importantly, available as an equal tyre in at least three diameters with one width. I excused the smaller sizes as these are aimed at cars of 1000cc. The Silverstone reared its head as an eminently suitable tyre. The fact that it was partly intended for gravel was not a big factor once I realised the gap between tread blocks was much less than 10mm and the compound selected was of a fairly hard and durable nature, meaning that once the shoulders were rounded, which the manufacturers duly obliged, the tyre would be suitable for all surfaces with minimum damage to gravel roads.
A comprehensive test programme was carried out under the watchful eye of the MSA and the Forestry Commission, the latter being hard masters to please. The performance was considered more than adequate on both surfaces and the wear on the gravel road surface was considered negligible under the watchful eye of all parties. In my view this sort of evaluation far exceeds the hearsay and rumour that now surrounds the tyre selection and gives very little credibility to those people who have stoked unsuspecting land owners to refuse cars with this tyre. Although the tyre was higher priced, it is anticipated (and no one has yet said that this is not the case) that this tyre will last much longer than a Colway.
Kenny Owen, being a man who can make a quick and positive decision, went with the Silverstone tyre immediately (in all honesty having no other option) and it was assumed that other Endurance events would follow suit, certainly for the foreseeable future until a different tyre entered the arena and proved its worth.
What has actually unfolded beggars belief. We now have cars running on a mish-mash of different tyres with none of the competitive sizes being the same. While I can understand competitors wanting cheaper tyres, in the overall scheme of things tyres in Endurance Rallies are not an enormous part of the budget. The most important aspect is having all competitors on an equal footing with no driver being seen to take a tyre advantage. Balloting competitors on what tyres they would like, shows a complete weakness of organisation direction. It is like the Government asking motorists how much tax should be on petrol. A good organiser will set his parameters, create his own rules and see that they are followed (like Philip Young always did).
I am aware of the impending arrival of a range of Sportway remould tyres as I was a party to some of the design at an early stage and I have every reason to believe that they will eventually have a future. But the product is unproven in many ways and unless some of the changes I have suggested are made, the tyre may not be suitable on all occasions and the thought of it being in different compounds makes me shudder with disbelief.
So, come on chaps, get your act together before Endurance Rallying goes the same way as other branches of Motor Sport which have suffered no leadership. Stick to the Silverstone tyres or, should I say, give it a fair chance, then evaluate the Sportway when it is a proven product and then make another bold decision and select one or the other.
Fred HendersonTyre Notes from Jerry at Service and Sport
Jerry is the Silverstone Tyres expert at Service and Sport and he's ready to deal with your tyre questions.
Give Jerry a call on 07789 392080 if you have any tyre questions
To answer some tyre size and price FAQs
The Silverstone size you see, for example 15/60-14, this is an engineering "dead" measurement, the 15 refers to the cm width of the tread, the 60 refers to the cm diameter of the tyre and the 14 is the wheel size. This type of sizing is used to help people determine their gearing properly as using aspect ratio tyre sizes, in engineering terms can vary by up to 10% between makes.
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Hope this helps. The size conversions are approximate and bear little resemblance to any other manufacturer sizes. All the technical info, including pictures and a brochure download can be found on www.serviceandsport.com.
JerryTYRE TESTING DAY 18/12/2007
The tyre testing was carried out by an impartial and regular competitor on Endurance rallies, Paul Flinders. Paul used to work for a major International tyre company and understands everything tyres. Paul stated, "I am extremely impressed with the testing, these tyres will do at least two rallies, grip better and cause no more damage to road surface that the previously used Colway tyre". The photographic evidence and report findings (below) reiterate this.
Venue: Epynt Ranges, Wales
Weather: Very cold and dry (-2 chill factor).
Tyre: Silverstone (505 M&S) S5 with E marking and (For Rally Use).
Tyre Compound: Medium, however, the hardest the company do.
Roads used: Twisty Forestry track and fast smooth Tarmacadam.
Forestry: 1.5 miles of twisty tracks with all sorts of bends both left and right and also both up and down hill. Some bends were damp where the wind didn’t get to.
Tarmac: 1.5 miles of fast smooth cold tarmacadam with a selection of tight bends to very fast and flowing. Uphill and downhill with a hairpin and lots of brows.
Car: Suzuki Swift (‘Endurance Rally’ prepared).
The road surface, Image 1, was a hard, forestry type with very fine loose dusty gravel on the surface. Image 2, shows the tyre as it is before the sides being buffed. Image 3, shows the same make of tyre with some buffing work done. This being on the very edge only. Image 4, shows the same make of tyre with full buffing, which now makes the tyre look like a proper ‘road’ tyre. This is the set of tyres that were used during the testing day.
Image 1 - hard, forestry with very fine loose dusty gravel on the surface
Image 2 - Silverstone 505 M&S before buffing
Image 3 - Silverstone 505 M&S with some buffing done
Image 4 - Silverstone 505 M&S fully buffed
The first test was carried out using a set of Colways competitively over the forestry roads. 4 times one way, and 4 times the other. The following images 5 to 10 are of various bends on the section after the Colways run through.
Image 5 - going into a 'Chicane'
Image 6 - out of a 90˚ left with soft ground
Image 7 - out of a 90˚ left with soft ground
Image 8 - a steep 90˚ left uphill and is quite wet on the exit
Image 9 - the approach to uphill left in Image 8 out of a 90˚ left with soft ground
Image 10 - going out of a 60˚ left
The Colways were removed, Image 11, and the Silverstones were put on, Image 12, and the section was used again, but this time the car went through 10 times each way, which would account for 20 runs through the section at ‘competitive’ speeds.
Image 11 - Colway as removed
Image 12 - Silverstone as fitted
Image 13 - same location as Image 5 above
Image 14 - same location as Image 6 above
Image 15 - same location as Image 7 above
Image 16 - same location as Image 8 above
Image 17 - same location as Image 9 above
Image 18 - a ‘close up’ of view between images 16 and 17
Image 19 - same location as Image 10 above
Image 20 - front tyre after gravel testing
After the gravel testing, Image 20 was taken of the front tyre. Image 21 is of the gravel road surface after the testing. The 1.5 mile tarmacadam section was run six times each way giving a total of 18 miles. The driver pushed the car to the limits all day and even in freezing conditions the tyre temperature was 40˚ at the middle part of the tyre. The final Image 22 is the same tyre after the tarmacadam test.
Image 21 - gravel road after testing
Image 22 - same tyre as image 20 after tarmac testing
Drivers comments:
The driver liked the way in which the vehicle was handling on the
gravel. The only difference was that the rear end of the car moved around more. On the tarmacadam test, the tyres held on to the road very well and only at high speeds did they give way, but that was in excess of 75mph. The driver was very happy with the way the tyre performed and the way that they lasted.
Observer’s comments:
All of the gravel road held up to the test, the only damage shown was the light gravel dust being swept away. At the chicanes where the vehicle was pushed off the ‘main’ road onto the lay-by, the larger loose gravel was moved, but the road remained undamaged. On the tarmacadam section the vehicle held on to the tarmac very well. The surprising part was how the tyres stood up to the testing. The Driver, who is very experienced, was informed to go out and try the tyres to his maximum capabilities. He was also asked to do as much damage to the road as he could. He informed me that he did try to cause as much damage to both tyres and road as possible, but failed on both counts.
Conclusion:
The tyres lasted well, and they did not damage the gravel road.
Andrew Thomson
Appointed MSA Observer (71788)
