Tyre choice for road (again)

[vertew]

The CR500s on my CSR260 are on their last legs, so I've finally decided to grasp the nettle of looking at other tyre options, given that CR500s are discontinued (though new old stock seems to still crop up here and there).

I'm sorry to see the CR500s go.  Even though they're ancient tyre tech by today's standards, they were designed specifically for our cars.  I've read a lot of comments on how the heavier / newer tyres have stiffer sidewalls, which can make the car feel less nimble and worsen the ride over poor surfaces.

Here's the little journey I went on …

My requirements are:

• I just use my 7 for occasional early morning blats, with no touring and a very occasional track day.
• I don't go out in the wet, so don't need a tyre to have wet capabilities.
• Due to the early mornings blats, temperatures can be quite low, even in the summer months.  I do need a tyre to get up to temp on the road, when ambient temps are often below 10deg.
• I don't want to change the wheel sizes, so I'm restricted to tyres which fit the unusual 245/40r15 CSR rear.  Front is the relatively common 195/50r15 (should be 195/45r15 but Avon have seen fit to not produce this size).

After a good old trawl of the forums, unless I change wheels, CSR options are quite limited and seem to be:

• Road tyres: source almost extinct CR500s, or ZZS
• Track tyres: ZZR or Nankang AR-1

These are all great tyres, so not a particular problem, though the Kumho V70's are very highly rated as are the Yoko AO48.  Given free rein on sizes, I'd have probably gone with the Kumhos.

I had a good look at the Nankang AR-1s that (ok I admit it) have a cool, minimalist tread pattern (!), but seem to be even heavier than the ZZ/R/S which themselves are significantly heavier than the CR500.

In the end, my dilemma came down to just tyre temps.  I really wanted to try semi-slicks, but I couldn't ignore all the comments about how hard it is to get heat into ZZRs and keep it there.  My 7ing is all early morning blats, where ambient temps are low - even in south east, often not much above 7 deg until well into May.  There was a risk I'd be constantly dropping in and out of the tyres working temp range, possibly giving weird grip effects.

So, I went for the safer choice and got a set of ZZS.  They're highly rated as a track tyre as well as road tyre, they come up to temp relatively quickly and have a lower working temp.  Should I get caught in some serious rain, there's no need to be too concerned - the ZZS is the selected wet weather choice for some race series.

I'm still very curious about ZZRs though.  If my balance of use switched more to track, I might have a change of heart, or better still, just buy a set of ZZRs for track.  If anyone is using semi-slicks / ZZRs for mostly dry road use / in low temp conditions, would be good to hear how more views.

I'll try to remember to add a comment on how I get on with the new tyres, as well as making the fronts fit under the cycle wings.  (Easiest solution looks like slotting the hole for the front wing-stay bolt, which would allow the cycle wing to be simply be pivoted up slightly).

I've attached a pdf here with some of the info I gathered from my forum trawl, hope that's useful to some.

tks, Andrew.

[Jonathan Kay]

Really impressed with the homework. Andrew.

How about turning that into a Guide/Wiki?

Jonathan

[vertew]

Thanks very much Jonathan 

I've had a look at the Guides area, is this what you mean?  Can't seem to see info on how to submit some content, could you point me in the right direction?

tks, Andrew.

[Jonathan Kay]

I think that you start here.

Jonathan