Avon ZZR vs ZZS - longevity.

[rotorwings]

ol said:

Did you end up getting the ZZS?

I ended up going for the ZZRs against the better advice on here. If I'm really honest, it was probably the cool look of the ZZRs that made me do it.

And I can now say from experience: they are too much for the road. I did one track day on them and once they are up to temp, they're in a different league to anything you can achieve on the road.

They have lasted well, but are feeling like they've lost their initial stickiness.

When I replace them, I will definitely get some ZZSs.

[mcerbm]

framerateuk said:

I've been told that the ZZS and ZZR are the same compound, but thanks to the ZZRs pattern, they last longer on track due to less movement in the tread blocks. Actual lap times would be very similar if not the same, but the ZZR would be able to do lap after lap while the ZZS will eventually overheat.

I'd imagine on the road you'd be looking at very similar wear between them both. I am surprised you've worn your CR500 out so quickly, I've done 3 trackdays at Llandow on mine (which is very hard on tyres) and one at Pembrey (in 30+ degree heat), lots of road miles and still have lots of tread left.

not sure who told you that but its not true. ZZR was offered in 3 compounds, the tyre sold by caterham originally was a "medium" and had the code A60 i think, there was also a soft in compound A24 not available from caterham but used for sprints and hillclimbs but has now been moved to MSA list 1c in the blue book. There is now a new compound which I think is A64 which was developed with avon for the 620R and I think is the only compound caterham now sell. it is slightly harder than the original "medium" but is eligible for sprints and hill climbs as it is in list 1b. The ZZS was developed to replace the CR500 and I think it is only available in one compound. Its ultimate grip is less than the ZZR A64 compound but will heat up quicker and is much better suited to road use.

[craig2003]

I have just changed on to ZZR's on my 620R, it is the third set of tyres both previous being the ZZS, they lasted a little over 4000 miles a set. Absolutely brilliant in proper flooded road wet as I found out coming back from Knockhill in a thunder storm. The new tyres have done twenty miles so too early to say how they are but they look awesome!

[mcerbm]

craig2003 said:

I have just changed on to ZZR's on my 620R, it is the third set of tyres both previous being the ZZS, they lasted a little over 4000 miles a set. Absolutely brilliant in proper flooded road wet as I found out coming back from Knockhill in a thunder storm. The new tyres have done twenty miles so too early to say how they are but they look awesome!

You will enjoy the ZZR's at knockhill Craig, they should be worth a second at least once up to temp. What sort of times are you getting out of the 620R round knockhill? I have a k-series Caterham with 213bhp that I use at Super Laps Scotland and I always wondered what sort of times the bigger power caterhams with sequential's could do.

[framerateuk]

So on the theme of ZZS and ZZR...

I currently have two sets of wheels, one with some old CR500's that are due replacement soon, and another with ZZS.

Big difference between the two on track, my question is, do I replace the CR500 with another set of spare ZZS tyres, or go with some ZZRs? The car is a 140 Sigma. With that amount of power will I really notice the difference or will the ZZS suffice?

[upsidedownmark]

No answer, but are you saying there's a big difference between zzs and cr500, in which case I'd be interested to know (as my cr500's are on their way out).. thanks.

[framerateuk]

upsidedownmark said:

No answer, but are you saying there's a big difference between zzs and cr500, in which case I'd be interested to know (as my cr500's are on their way out).. thanks.

Way more grip on the ZZS. You can really lean on them in fast corners. Arguably the CR500 are more progressive in the way the grip starts to slip, but I think this is quite common with slicker tyres from what I've read.

[mcerbm]

The ZZS is a good all round tyre and is the replacement for the CR500 from Avon, I personally think that it is an improvement in almost every way, however I think I read the weight is slightly up on the CR500 affecting in-sprung mass.

On a 140bhp sigma you could get a lot of fun out of the ZZS, Although a set of ZZS will help your ultimate lap time and I also think its quite progressive for its ultimate grip, but I wouldn't go with ZZR as my single tyre. its good to have a set of alloys to interchange. If you have both ZZS and ZZR you have all combinations covered.

I'm also sussing out getting a set of CR28sports for doing competitive events when its chucking it down. Which at Knockhill it usually is!

[upsidedownmark]

Cheers. Didn't think the CR500 was lacking in grip, loving the car in fast corners

[craig2003]

mcerbm said:

You will enjoy the ZZR's at knockhill Craig, they should be worth a second at least once up to temp. What sort of times are you getting out of the 620R round knockhill? I have a k-series Caterham with 213bhp that I use at Super Laps Scotland and I always wondered what sort of times the bigger power caterhams with sequential's could do.

I have not actually timed myself going round, looking back at the gopro footage though shows it at around 57

[Order66]

mcerbm said:

I always wondered what sort of times the bigger power caterhams with sequential's could do.

I've done late 54s on some used slicks - but admittedly not the bravest driver, I reckon the car has 53s poss late 52s with a good driver

[DCL]

Here's what a professional can do with 265 BHP and a Sadev sequential on road tyres round Knockhill.

https://youtu.be/xcYWmrCkmT0

I have never matched that myself, but nice to know what the car can do it! Probably there's a 52 sec in there with some more practice.

Also Congratulations to Rory Butchers who makes his BTCC debut at Knockhill this weekend

[coppice]

Paddle shift? Pah !

[mcerbm]

That's still very reasonable order66, what is the spec of your car?

My best is a 55.1 on the ZZS, I feel a bit horsepower limited on the straights and the vbox shows a surpising amount of time lost on manual gear changes!

David (DCL) it would be interesting to compare your sadev vbox times to my manual to see theoretically what I am missing by swapping cogs myself.

To keep back on track though I was impressed with the ZZS on track and I thought the CR500 was a good road tyre but went off a bit quick on track and didn't have the ultimate grip of the ZZS. But the ZZS was still progressive. Apart from a slight weight increase the ZZS is better than the Cr500 in every way IMO

[Order66]

mcerbm said:

That's still very reasonable order66, what is the spec of your car?

That was a factory-spec 620R

[DCL]

mcerbm said:

David (DCL) it would be interesting to compare your sadev vbox times to my manual to see theoretically what I am missing by swapping cogs myself.

Some would argue that I'm the one missing out .

It's not as much as you think - half of them are down shifts, and there's no technical advantage. On the up shifts there is a tenth or two, but this soon gets swamped by aerodynamic factors (ie any advantage causes more drag) and the Vmax at the end of the straights is really down to BHP. The best way I found to analyse it was to look at the 'average percentage' throttle for the lap (I find that the most accurate parameter to predict lap times) and I would be lucky to see +1%.

In practice the real advantage is to be able to change gear anywhere without upsetting the balance, and an increased spacial awareness and precision. By having both hands on the wheel and not moving (to change gear) you can commit a little more, particularly during braking. That's probably worth more than the technical side.

Edited by DCL on Monday 14th August 10:44

[mcerbm]

Even if it's tenth I'll have 6 upshifts per lap. Half a second or so a lap would be healthly in the 54's for me. Like you say it's also less of a distraction on a lap especially on braking if you don't have to heel and toe and only have to concentrate on brake pedal pressure.

Too pricey for me to change but it's nice to have some extra excuses!

[Order66]

mcerbm said:

Even if it's tenth I'll have 6 upshifts per lap. Half a second or so a lap would be healthly in the 54's for me. Like you say it's also less of a distraction on a lap especially on braking if you don't have to heel and toe and only have to concentrate on brake pedal pressure.

On my previous megabusa I got an easy 1s a lap from changing from the "manual" sequential to a full paddle-shift system. There were 2 factors - first being left-foot braking, I never really mastered it but the ability to change the balance without lifiting off made a big difference to eliminating understeer. However the biggest diference I found was being a lot more confident and late on the brakes - I find it difficult in the 620 coming into the hairpin and trying to knock down 3 gears, heel/toe and confidently brake with 1 hand on the wheel, and have made an arse of it a few times to the point I now brake too early everywhere, leading to lower apex speeds as well.

I would love to fit a paddle-shift to the 620 but there is nowhere that will simply take the car+money and return it working. Lots of people want to sell "systems" but nowhere will take responsibility to get it working and in the car.

[DCL]

Order66 said:

I would love to fit a paddle-shift to the 620 but there is nowhere that will simply take the car+money and return it working. Lots of people want to sell "systems" but nowhere will take responsibility to get it working and in the car.

The problem is that engine response is as important as the paddle shift system itself. My paddle shift project started with the engine specification. I doubt the 620 Duratec would be easy, or cheap to get a good result. It would work, but it has just not been designed for that purpose.

[sfaulds]

DCL said:

The problem is that engine response is as important as the paddle shift system itself. My paddle shift project started with the engine specification. I doubt the 620 Duratec would be easy, or cheap to get a good result. It would work, but it has just not been designed for that purpose.

The 620 engine started life with paddleshift, long before it made it into a seven.