Avon ZZS vs Toyo 888r for the road

[slime bomb]

I've recently swapped my fantastic ZZS's for the 888r's on my 420r and noticed that the car seems to be a bit on the bouncy side. All are set at 18psi cold the same as the ZZS's were but they definitely don't feel anywhere near as good as the Avon's were.

The ZZS's were just planted but the Toyo's don't give me the confidence. I'm going to try 16 psi in the rears and see if that helps. It's only driven on the road but in a VERY spirited way.

Has anyone else experienced this? Any thoughts would be gratefully received.

[AWRacing]

My guess would be that its because the Toyos will have a bigger sidewall than the Avons. I wouldn't drop the pressures as that'll exaggerate the 'bounciness' you are feeling.
Are you on a staggered set-up? 185 from 215 rear maybe?
You may need to get the geometry reset, depending on the difference in profiles between the Toyos and Avons. If they work out the same you should be ok as the whole car will have raised slightly by the same amount, nothing you'd really notice on the road.

[WombleCate]

+1

When we swap between ZZR and 888 (non-staggered) we have to adjust the rake. There’s a head scratching moment, as you have to adjust the rear more than the front. Apologies, I can’t remember how much at each end…

[bosshog]

I’m new to 7s but i dropped the pressure to 16 and it definitely helps the ride. I need a new set soon - it seems the new ZZRs are for racing only, but theres nothing saying so on the side walls…

I do like how quickly they warm up on the road though.

[slime bomb]

Mine are the staggered set up and I have read about some people having to get the ride set up again. I'm just waiting for the roads to dry up so I can see what 16 psi is like. Apparently it's better because of the slightly bigger footprint, we'll see...

[WombleCate]

bosshog said:

I need a new set soon - it seems the new ZZRs are for racing only, but theres nothing saying so on the side walls

I do like how quickly they warm up on the road though.

The Toyos have their strengths (consistent level of performance for longer), however, once warmed up the grip of the Avon/ Nova are in a different league.

I believe the Nova ZZS and ZZR are the same tire as the Avon's and should perform exactly the same on the road, however, I guess getting homologation is expensive.

[slime bomb]

Well, I managed to get out yesterday for a few hours and I don't know if it's phycological or not but it did feel more compliant and slightly less bouncy with 16 psi in the rears and two people. What I did find after I got back home was there was only a change of 1 psi in all four tyres, is this normal?

[WombleCate]

Sounds about right on the road.

On a warm track I’d expect them to increase about 3-4 PSI over twenty minutes.

I think you’d want a warm temperature of 24-26 psi. Given the difference in side wall (especially when staggered) I’d recommend changing the rake angle.