Kumho v70 tyres... (again)

[Eugene7]

Ok, I've been using Yoko A021R tyres for years, but as we all know they are no longer road legal...
With Eugene I prefer 185/70/13 tyres - they handle far better on an older 7, and I need the ride hight as we do a lot of fast road miles.

But, the actual question is, what compound to go for with the Kumho v70's?

All the reprobates in Le BOG Club would simply say soft, or even super soft, and smile wide until the tread ran out...



I'm trying to be a bit more thoughtful on what's best for fast road use, especially as we do a lot of hard miles in the summer across/around France/Spain, etc.

(Feel free to look at previous blatts: http://www.7-dna.com/forums/index.php?action=vthre... and the year before: http://www.7-dna.com/forums/index.php?action=vthre... )

I guess the choice is soft or medium?
Eugene is a 210BHP Zetec, with Ital live axle, and wide-track front.

Thoughts?

[Eugene7]

I'm trying to check road legality...
The info available via different suppliers is rather confusing...

[Eugene7]

From Camskill:

Yes they are road legal, but you do need to inform your insurance company you are using them on the road as they are primarily a track tyre. and the E mark on track tyres is really so you can use them to and from a race track.

So that should be fine, as most Caterham insurance companies will understand their use.

[Eugene7]

And from Demon Tweeks...

Yes they are road legal.

With no comment on insurance, or any other comment at all...

[Eugene7]

Mmmm - seems 70 profile Kumho's are a bit like rocking-horse st...

So, what alternatives?
Should I just go 60 profile???
What about 60 profile 185/60 13 NANKANG NS2R? They are a lot cheaper too...

I really would rather stick with 70 profile, but if I have to I'll give 60's a go - but what tyres to suggest?
(Something other than Kumho, just as a suggestion...)

[Eugene7]

Have spoken to a number of the Kumho suppliers now, and it seems stock will be available beginning March...

Think I'll probably just wait.

[Eugene7]

Price is around £100 per... depending where you manage to source them.
I'm still faffing about soft or medium compound.
I don't expect to get that many miles out of a set, but intend to have fun!

[Eugene7]

Some Gump said:

Why not Avon's? Great tyre that lasts for ages.
Kuhmo v70 Better in the wet, but a decent drying session and they melt like butter...

Simple - because Avons do not come in the required size...

[Eugene7]

BigCol said:

at £100 a corner, not so different to these, Steve...
https://caterhamparts.co.uk/zzs/5246-tyre-avon-zzs...

which have got reviews in terms of both grip and longevity... or are they too thin at 55 profile for Eugene?

No way an I ever putting 55 profiles on Eugene...
With the suspension setup correctly I'd hit anything bigger than a fag-but!

[Eugene7]

BigCol said:

at £100 a corner, not so different to these, Steve...
https://caterhamparts.co.uk/zzs/5246-tyre-avon-zzs...

which have got reviews in terms of both grip and longevity... or are they too thin at 55 profile for Eugene?

You posted that already... and I replied

Way too bloody small!!!

[Eugene7]

Some Gump said:

Why not just wind the platforms down? Takes 15 minutes, tops.. We used to have to move them to move between CR500 and V70 for wet - became quite routine. It really makes a difference when we did a full year of track days on 1 set of CR500 fronts, but ruined our first set of V70's in a day on a drying track (before we realised turning a platform was more cost effective!)

As answered, for correct geometry you cannot just 'wind the platforms' up...
You need to set the correct front geometry first, and then set the back accordingly.
As a rule of thumb, the front lower wishbones need to the parallel to the ground.
(Just a rule of thumb, but that will get you close.)
I sent a lot of time getting my geometry right, and altering it just ti get more ground clearance is not something I want to consider...

[Eugene7]

So, the latest on this saga...

Kumho now say they are unlikely to make any more v70's in 70 profile...

I have looked at swapping to different rims, to allow lower profile tyres with a similar overall diameter, but that's difficult with my PCD.
(Ital)

So, at least for the next tyre purchase I'm going to go with a more 'standard' tyre of the correct size for me.
The options seem to be:

[i]Uniroyal RainExpert 3
Continental ContiEcoContact 3
Nankang Econex NA-1
Nexen N'Blue HD Plus
Kumho KH17[/i]

Does anyone have weight info for the different tyres?

So... what to go for???

Edited by Eugene7 on Monday 20th March 21:49

[Eugene7]

Unfortunately, you can't 'wind up the platforms, and sort out the handling later'...
The platforms must be positioned to set the handling, not the other way round.
(Rule of thumb, the lower wishbones should be parallel to the ground.)

[Eugene7]

Yeah, I can't argue with that!

[Eugene7]

Ok - tyres ordered!

Toyo Proxes R888R
2x 185/60r13 for the front - 2x 205/60r13 for the rear
The recommended rim size for the 185 is 5.0 – 6.5, and for the 205, 5.5 – 7.5.
I will be using 6 all round.

[Eugene7]

With around 210 BHP, and limited slip diff, the wider rubber is a choice I've been thinking of for some time.
With the 021Rs I could easily break traction at the rear...
I'm not 100% convinced, but feel I owe it to myself to try.

[Eugene7]

As Toyo recommend 5.5-7.5 rims for the 205 tyres I think my 6 rims will be ok.
I did also check with George Polly, and he also says they will be ok... if a little 'ballooned'.
(Little was his word. I have no idea if it will look too much or not, but I can live with it for the duration of one set of rears...)

I do have an issue as I run an Ital axle, and it is difficult to get different size rims of my type for that PCD now.

I did also check with this site: http://www.tyresizecalculator.com/tyre-wheel-calcu...
(Not sure if it is that accurate thought...)

[Eugene7]

We are also trying to collect info on different sump clearances here: http://www.7-dna.com/forums/index.php?action=vthre...
The more the merrier...

[Eugene7]

Got the tyres - will be fitting next week!

[Eugene7]

Not got around to putting the tyres on the 7 as yet...
Should happen in the next week or so - just a lot of other stuff happening at the moment...