Is it the wheel size or the Tyre Profile?

[61]

Having read a lot of posts about wheel and tyre preferences on here, it seems there's a lot of preference for 13 inch wheels. Avon ZZS are spoken well of, but they are a 55 profile. It's often been written that 13's provide a better ride.

I drive on the road and don't track my car. It's an older 88 de dion super sprint. I'm looking for a good ride quality. So should I rather be looking at a 14 inch wheel because I can easily buy an Avon ZT7 60 profile or even 65 profile tyre or is there something in the lighter unsprung dynamics of the smaller wheel and tyre combination that assists ride comfort more? I had thought a higher profile would produce a slightly better ride, but I read a lot of praise for the lower profile ZZS.

So I guess my question is whether ride comfort is about tyre profile or wheel size. 

[Tazio]

Decent dampers help with the ride..

[StevehS3]

Tyres really so seem to be a personal choice. I recently had 13" with ZZS, now 13" with R888R and also a set of 14" with Rainsports. In order of comfort Rainsports best (by a considerable margin) followed by R888R (60 profile) and finally ZZS. If comfort over pot holes and rough roads and excellent in the wet is a priority I don't think you could do much better. The trade off is dry grip which is nothing like a track day tyre but good enough for normal spirited blatting. All IMO of course and tyre pressure is obviously a factor.

[Wrightpayne]

What are you running currently? 
 

For ground clearance for solely road use I'd run 185/70R13 or 185/60R14

Uniroyal Rain Experts are available in these sizes. I've not used them personally but lots of recommendations on the forum for these as a good compromise for the road and safe in the wet.

 

Ian

[Bricol]

Check your tyre pressures - I've run around 16 psi most of time. 

Higher for long distance in high temps, loaded up - to the south of France etc in one long motorway hit.

[Golf Juliet Tango]

I have always favoured 60/65//70 profile 13" tyres on my Seven. These are becoming ever more difficult to source. Despite the post above, I was unable to replace the Uniroyal RainExperts in 13" which had worn out.

I had to settle for some Hankook tyres.

I do so miss Yokohama AO21Rs.      

[timb2117]

Gosh tyres are a  whole subject of their own. Generally;

I was always advised that never rely on your tyre/ low pressure for what is a function of the suspension (softness/ stiffness) 

A larger tyre/ wheel will roll over and through bumps better. - A heavier car will do the same.

However as we have one of the lightest cars and little load on tyres on the road, I would try the 16 psi with as large a profile tyre/ and wheel as you can squeeze in........But seriously consider some soft dampers/ springs.

The counters are huge and it is a huge trade off with no definitives - its lots of laws of complex physics....Way over my head and I guess that's why race teams spend gazillions on this aspect.

Sorry one other thingo make sure your tyres are as new as you can get, here in OZ they're cactus from heat and UV after 5 years!

[SLR No.77]

Good suspension really helps but it only counters the up/down movement of the wheels, contrast this to the tyres which will move and squirm around in multiple directions often at the same time. IMHO this is why tyre choice on a lightweight car is so important to the ride and handling characteristics. 

In my experience my favourite tyres have been ACB10s, AO21Rs and CR500s. Unfortunately the first needs a specific suspension setup and the other two are no longer available! However they were all designed for lightweight cars which few tyres are.

More recently I've been using Avon ZZS's  which felt good ... until I refitted my old CR500s which transformed the car! Until someone starts manufacturing something similar to the CR500s my preferred choice will need to be the ZZS. Just avoid anything heavy or with stiff side walls, or at worst both!

Stu.

[aerobod - near CYYC]

For track use only, Formula Ford sized slicks work well as they are designed for a car that is a bit lighter than a Caterham, otherwise there isn't really any current road tyre that was designed for a car the weight of a Caterham, now the CR500s aren't really available. The lack of weight of the Pirelli and Hoosier slicks on 13" wheels I've used is quite noticeable compared with the 15" road wheels with tyres designed for a 1500kg car.

[Golf Juliet Tango]

Do we know why the CR500s were replaced by the ZZR & ZZS? Of we were told, I have forgotten. (I should look in the archive).

[StevehS3]

I think it was said that CR500s wouldn't meet current regulations. The CR500 cracking was an issue which ZZS doesn't seem to suffer from. 

[Golf Juliet Tango]

And presumably that Avon could not/would not solve.