So, maybe it is time for 13" wheels, but what size tyres?

[rotorwings]

Currently - R300D 6Sp w/ 195/45 R15 x 4

I'm considering moving to to 13" inch wheels because of the good things I have heard and the fact that ZZRs & A048s are not available in the right 15" size for me.

So, what size should I be going for?

The car has so far not seen a track, so I am not concerned about lap times.
I don't want the car to feel 'over tyred', so I want to avoid having wide rubber as much as possible.
I also do not want to reduce the circumference of my rears at all, as the gearing, and ground clearance, is low enough already.

I was thinking about the following options:
ZZRs
Front - 185/55 R13 on 7" Wheels
Rear - 215/55 R13 on 8" Wheels

Will this be just too much rubber for an R300?

or
A048s
Front - 185/60 R13 on 7" Wheels
Rear - 205/60 R13 on 7" Wheels

All feedback or further suggestions welcome.

[framerateuk]

Why go for ZZRs if you're not intending on going near a track? I'd stick with the ZZS instead as they're made from the same compound but offer a tread pattern that will perform far better if you're caught out in the rain - plus they're still fantastic on a dry track.

Your sizes look fine to me. You could probably use the smaller size all round if you wanted (I do on my 140). Depends what sort of ride you're after. The smaller wheels at the back make the ride a bit more fussy, but the car does feel very alive, and you save some weight too.

However, whichever set you go for (small or large on the back) you'll need to adjust the suspension again.

Edited by framerateuk on Monday 5th October 19:40

[Gingerbread Man]

I have the second set of sizes mentioned:

Front - 185/60 R13 on 7" Wheels
Rear - 205/60 R13 on 7" Wheels

I guess these aren't tyres for the road, as A048s aren't legal any more unless old stock, Toyo 888's though are available in that size and are legal.

[rotorwings]

Thanks for the input.

I am not concerned about performance in the wet at all, as I never drive in the wet. So I think the ZZRs would be better for me (I've nearly used up a set of 4 CR500s in about 1600miles). Plus they look 'cooler' with less tread.

I hadn't heard about the A048s not being legal. Is this a UK thing? I am in Germany, so perhaps they could still be legal here?

@Gingerbread Man - how do those sizes sit on the 7" rims? Would there be any sense in going for a wider rim at the back (or narrower at the front) if I was starting from scratch? Or do they fit perfectly fine?

What would be the limit for tyre width on a 7" wheel?

[tomwoodis]

When I bought mine (same engine as yours) I opted for the 13inch wheels from the outset. They are staggered, 7inch at the front, 8 at the rear. The tyres are staggered too so wider at the rear (I'll check sizes for you later). The rims are currently wearing CR500 and I'd have to say the combination is very good. Certainly not overtyred at the rear, I was breaking traction quite easily exiting corners on the last track day I went on. I think the diff (which I presume you have?) makes sure of that.

[fergus]

I'd echo the comments about waiting for the ZZRs to warm up before really pushing on the road. They have a lot of rubber and a very small land:sea ratio, so tread block movement isn't really going to help get heat into the carcass.

I think they're overkill for the road. However, once warm, even with an LSD, they need a big right foot to unstick them, assuming your suspension is somewhere near sensible settings!

[framerateuk]

rotorwings said:

Thanks for the input.

I am not concerned about performance in the wet at all, as I never drive in the wet. So I think the ZZRs would be better for me (I've nearly used up a set of 4 CR500s in about 1600miles). Plus they look 'cooler' with less tread.

I hadn't heard about the A048s not being legal. Is this a UK thing? I am in Germany, so perhaps they could still be legal here?

@Gingerbread Man - how do those sizes sit on the 7" rims? Would there be any sense in going for a wider rim at the back (or narrower at the front) if I was starting from scratch? Or do they fit perfectly fine?

What would be the limit for tyre width on a 7" wheel?

That's fair enough, the ZZR should be fine then (thought I must admit, I do prefer the CR500 to the ZZS on the road as they're much lighter).

Why not go for a 6" front and 8" rear as Caterham would supply?

[mharris]

framerateuk said:

Why not go for a 6" front and 8" rear as Caterham would supply?

Agree with this. Not sure where everyone is getting their 7" wheels from because 6" is the norm from Caterham. 7 inches puts you right at the upper end of what will fit an Avon ZZR 185. Whereas 6 inches puts you comfortably in the middle. The 6 inchers will be lighter as well - think of all the unsprung weight savings!

Personally I'd get 185 front and back, but then I enjoy lively, playful handling rather than lap times.

[Hooch747]

I would stick with 185s all around, unless you have an engine upgrade you will have a much better handling balance.

[framerateuk]

Just to add, if you're worried about a loss of grip going from 195 width CR500 to 185 width ZZR, don't be.

I noticed the step from 195 to 175 profile CR500 (so, 15" to 13x6 all round) gave me a far more predictable handling balance, while going from the 13" CR500 (175x13) to ZZS (185x13) gave me far more grip, but still predicable on the limit.

All in all, whatever you do, I'm sure you won't be disappointed. I sold my 15" wheels as soon as I bought a set of 13's and then got a spare set of 13's as well.

[Farlig]

Gingerbread Man said:

......as A048s aren't legal any more...

eh..?

[HurryUpAndWait]

Farlig said:

Gingerbread Man said:

......as A048s aren't legal any more...

eh..?

I believe there are legal and illegal ones floating around - there are those that are 'E-marked', which I believe are fine. Some retailers have not caught on to this, so caveat emptor.

[rotorwings]

During my online searching I have come across the following deal:

185/60r13 & 205/60r13 TOYO R888 TYRES (2 front, 2 rear)
4 x 13x7 Team Dynamics Pro Race 1.2 Wheels.

All new, tyres fitted and balanced, £700 for everything

888s are not my first choice, but as a package deal this seems pretty good.

Thoughts?

[Gingerbread Man]

HurryUpAndWait said:

Farlig said:

Gingerbread Man said:

......as A048s aren't legal any more...

eh..?

I believe there are legal and illegal ones floating around - there are those that are 'E-marked', which I believe are fine. Some retailers have not caught on to this, so caveat emptor.

Many have lost their E mark, so roadworthiness. Fine for track, but the tyres that have affected me were the Yoko 21's (which I currently have on) and the Yoko 48's.

I'll be switching to the new Toyo 888R's when I need to. A shame as I use my car daily, so the we weather capabilities of the Yoko 21 was nice to have. 48's and 888's came a bit dangerous come ice and standing water in the winter.

[Gingerbread Man]

Gingerbread Man said:

I have the second set of sizes mentioned:

Front - 185/60 R13 on 7" Wheels
Rear - 205/60 R13 on 7" Wheels

I guess these aren't tyres for the road, as A048s aren't legal any more unless old stock, Toyo 888's though are available in that size and are legal.

Sorry I might have got the 7" bit wrong. So excuse my stupidity.