Decoded in detail: Pete McNally
Who is Pete McNally?
Pete McNally, 45, is a local lad made good. After a secondary school education in Melksham, Avon’s home town, he gained a degree in maths, statistics and computing from Bristol University and then came back to Melksham to join Avon Racing as a technical trainee in 1987. After 10 years as a GP tyre engineer and tyre designer he became design manager for Avon’s motorcycle road tyre range, reaching his current position of product and design manager in 2005. Pete is also chairman of the ETRTO (European Tyre and Rim Technical Organisation) motorcycle sub-committee which sets European standards for tyre and rims.
Married with two kids, Pete has his pick of Avon’s development bikes, ranging from CBR600s to R1s and Fireblades, ZZR1400s, FJR1300s and Harley tourers. Outside work he enjoys a spot of trail riding over Salisbury Plain on his own XT Yamaha, playing squash, scuba diving, listening to heavy metal, and playing ‘Call of Duty’ online – but not all at the same time.
His proudest moment
“Quite a few things make me proud, like the fact we’ve got ‘made in England’ on our tyres. About 10 years ago I was keen to have a little Union Jack flag on the sidewall but it was deemed that might adversely affect world sales so we left it. When I worked in racing through the ‘90s, we won a hell of a lot of Supersport 400 and 600 races, and plenty of TT races with the likes of Jim Moody and Dave Leach. When these guys won on our tyres, and I was able to put the ‘Race Winner’ caps on their heads, that made me feel pretty good. Whenver I walk to the back of the factory and I see piles and piles of tyres and they’re all my design, that makes me feel good. In fact I feel like that every time I see a bike with an Avon tyre on it.”
Every Avon road tyre produced since 1997 was designed by this man.
What makes a good tyre good?
Development. All our sports and sport touring tyres like VP2 and Storm go through constant, ongoing development. Every couple of weeks we’ll have some new variants for our guys to test, maybe a new compound or a slight constructional change.
There’s been a lot of talk about dual compound and triple compound recently, but we’ve shied away from that for a number of years because for us that was old technology 10 years ago. Instead, we’ve got A-VBD, or Advanced-Variable Belt Density. A tyre is basically a platform on which to put the tread compound. The tread reacts differently depending on how the platform is built. The variable spacing of the belts in our tyres – close at the centre of the tread, more spaced out towards the tread edge – gives you the riding characteristics of a multi-compound tyre with a ‘hard compound’ feel in the middle for longer wear and a softer feel on the edges for more cornering grip.
We think VBD is a higher-tech way of doing things because it’s a gradual change, but it takes 20 minutes to explain VBD to people in bike shops, and customers like a yes or no answer to the compound question, so our latest tyres have got two compounds as well as VBD.
With bike top speeds growing faster than a banker’s pension, is there still a big window of safety built into sportsbike tyre design?
Yes. We rig-test most of our radial tyres, and certainly the W-rated ones, to about 220mph. The drum rig test is much more severe than normal riding. The rig tyre just sits on its centre patch which heats up. Any failure is always a small tread blister in the middle of the tyre. In normal riding of course you’re spreading the heat around the tyre.
For the German market we have to do TuV testing, which does involve high-speed cornering. Our testers go to a track at Idiada near Barceona which is basically a long straight with a curve at the end. It’s a pretty gradual curve. On a flat-out Hayabusa you barely have to ease down for it.
Every year all the main tyre companies spend two weeks down there with all the new models from all the main bike manufacturers. The main test is stability at full speed. We’ll induce a weave at full speed and note how long it takes for the weave to decay. There’ll probably be about 100 different bikes to test over the two weeks.”
Sounds like a dream job – or a nightmare. Have there ever been any nasties?
Fortunately no, not while I’ve been here, because so much testing has gone on before we put the tyres anywhere near a bike. Besides the drum testing and high-speed tests we’ll do endurance tests where the tyre will run at 60-80mph for 34 hours, with quite a high load on it. That will prove its fatigue resistance; 34 hours or 1700 miles is the pass mark, and then after we’ll just keep going, increasing the load and the speed. We’ll normally run them on to at least 4000 miles, which is equivalent to 180 per cent of the maximum load, and even then they’re usually all right.
Do tyre designers design tyres with an eye on the limitations of a bike, weighing up factors like ground clearance, or do bike designers design for the capability of the tyre?
Some manufacturers will design for the tyres’ ability. When I’m designing a tyre, the first thing to establish is ‘what’s it for?’. We can make tyres that will allow for a 50 degree lean angle, in fact you could build a tyre with no sidewall at all. But there’s a problem with increasing the tread arc, which is that most people won’t get near the edge. We tried it once and got a ton of complaints from people telling us we’d designed the tyre wrong because they couldn’t get anywhere near the edge.
Are there any magic new compounds coming through that will deliver the holy grail of grip and endurance? One of the biggest recent advances has been the inclusion of silica, which has happened over the last couple of years. Silica effectively improves wet grip. When someone wants 15,000 miles out of a sport touring tyre, you’re not going to be able to use a very soft compound there. You’re going to have to have a medium to hard compound which isn’t going to be that good in the wet.
Silica improves a harder compound’s ability to work in the wet. It’s all about temperature. A hard compound might not really work between 10 degrees and 90 degrees, say, and if it’s raining it might never get to that 10 degrees. Silica brings the effective operating temperature down to zero or one degree, so it will work in the wet. Silica also extends the tyre’s performance at the top end of the range by reducing the effects of overheating.
The only trouble with silica is that it’s very expensive and very difficult to process. Some companies used to put a tiny amount in their tyres and then advertise them as ‘silica’ tyres. A lot of Avon compounds are stacked full of it, so we call ours Super Rich Silica Compound just to get across to people that it’s not just a gimmick.
If you could achieve one thing now for the betterment of biking, what would it be?
I’d like everyone to be on Avons. Quite genuinely I think that would be a good thing. There are fatalities in motorcycling, that’s inevitable, so as a designer you feel a big sense of responsibility. My philosophy is to try to keep all riders safe by giving them the best tyres. We’ll always put safety first. If it’s a case of wet grip or mileage, we’ll tend towards extra grip. Some might criticise us for that, but I can sleep at night knowing that they’ve got as good a tyre as we can give them.
Will we ever be able to ride as quickly in the wet as we can in the dry?
Given today’s technology, I don’t think so. Because of the very nature of how rubber grips the road, the minute you put water in there you’re adding a lubricant. So we can reduce the gap between wet and dry performance all the time, but whether we’ll ever get them both to the same level, I don’t think so.
When I say ‘rubber’, in fact there’s very little natural rubber in a tyre. It’s too expensive to process. It’s almost all man-made synthetics now.
Are sports tyre tread patterns more about fashion than physics?
No, the tread pattern is really important. If you wanted a tread pattern just to clear water, you’d have a racing wet. But a road tyre doesn’t just have to clear water on wet roads, it has to run on dry roads without irregular wear and tearing on the edges. If you put the grooves in the wrong place you’ll get high spots and low spots.
We came up with the ideal groove pattern by taking a slick and cutting fan-shaped grooves into it to establish exactly where the wear was taking place, then we set up our road-tyre grooves at ninety degrees to those maximum-wear grooves.
But isn’t there one ideal pattern that everyone should follow?
From a physics point of view the grooves do have to follow a certain design. At one point it did seem that everyone else had missed the point on tread patterns. Without mentioning any names, you’d get horrendous stepped wear on some of their tyres, the fronts in particular. You had to throw them away long before they were worn out, simply because the pattern was all wrong. Avon pioneered inverted front grooves on front tyres, recognising the fact that the rear tyre is about traction and the front is about braking. For years people told us we were putting our tyres on the wrong way round.
There is a cosmetic angle as well. You don’t want to put a horrible-looking tyre on your bike.
Can’t sports tyres have thicker tread for greater mileage? If the tread gets much thicker than it is, the compound would have to be too hard, because thicker tread ‘moves around’ and creates its own heat. If it’s thick, it would retain that heat and then you get blistering.
Any tips on how best to extend the life of a modern tyre?
Ease it in. On modern tyres you can almost go for it straight off the bat. Most of our sport touring tyres today will outperform our sport tyres of just a few years ago. But if you regularly put full power through a cold tyre you’ll start something called ‘cold tearing’. Instead of lots of little tears, or what we call high-frequency graining, which is quite a normal part of easing the tyres in, you’ll get big tears and you’ll lose a lot of mileage.
What are the main challenges facing today’s supersport tyre?
Horsepower. The chassis are getting better, though even now you still come across the odd one which you think needs chopping up and throwing away. But the power keeps going up, and it gets quite scary for the tyre designer. If the bikes were limited to 80bhp my life would be a breeze.
Are some bikes more sensitive to tyre pressure?
Yes, some tyre manufacturers will make several different versions of the same tyre, with slightly different damping characteristics to suit certain oddball bikes. We tend to make one tyre that will work on just about everything.
Will we ever have runflat tyres or pressure monitoring systems on bikes?
Pressure monitoring is just starting to be looked at. You can already buy aftermarket systems. If it works, it’s a good thing. Runflats aren’t on the drawing board at the moment, but they may come. There are a lot of difficulties there, especially with high-speed handling. With this kind of thing we tend to let the car boys sort it out and then we’ll borrow the technology.
Some riders don’t use their bikes from one month or one year to the next. Is there a use-by date on a tyre?
Yes, the British Rubber Manufacturers’ Association say that you should use a tyre within six years of manufacture, and that it should be removed after 10 years. We recommend tyres should be used within five years of build and taken off after seven. There’s a four-digit code on the tyre, if it’s 2307 that’s week 27 of 2007, so you can tell how old it is. I saw an Avon on a bike in Daytona that I didn’t recognise. When I looked it up later I found it was 50 years old. He seemed happy enough racing around on it, but I wouldn’t have been.
Does racing improve the breed for streetbike tyres?
Yes, I do think that. Even though we’re not directly involved in racing at the moment we do a lot of development on the racetrack with our Viper Extreme track tyres. The design of those feeds into our sports tyres. A lot of VP2 technology came from that Viper Extreme development. Track testing is essential. We can send a guy out on a bike and he’ll come back and say ‘nah, that tyre’s rubbish, it’s sliding everywhere’, but track testing will give you a better perspective and maybe show you that the problem lies elsewhere, like in the suspension.
Do you benchmark other manufacturers’ tyres?
Yes. When someone else comes out with a new tyre, we’ll cut it apart, analyse it, and check there’s nothing trick in there that we haven’t thought of. I’m sure all the other companies do the same with our tyres. In sports touring I’d say we’re as good as the best, if not the best, and I’d say the VP2 sports tyre is as good as anybody else’s.
Our latest VP2s have had about a year and a half of development. We track test our tyres regularly, and if they’re not good enough relative to the opposition we don’t release them. We go back to the drawing board. The product life of a sports tyres is only two or three years. It’s a very fast-changing market.
Have internet forums had a big effect in terms of helping people to know what’s the best tyre for them?
I get 30-40 emails a day asking for tyre advice. Quite often my responses will end up posted on a forum somewhere, with a dozen people commenting on what I’ve said. We look at some of those forums and it’s difficult not to get involved because you’ll see someone putting up a load of incorrect information. At least I know what I’ve said is true. If you write anything on a forum, you’ll get so many responses you could spend your whole day on there.
If you could achieve one thing now for the betterment of biking, what would it be?
I’d like everyone to be on Avons. Quite genuinely I think that would be a good thing. There are fatalities in motorcycling, that’s inevitable, so as a designer you feel a big sense of responsibility. My philosophy is to try to keep all riders safe by giving them the best tyres. We’ll always put safety first. If it’s a case of wet grip or mileage, we’ll tend towards extra grip. Some might criticise us for that, but I can sleep at night knowing that they’ve got as good a tyre as we can give them.
