Using different tyres when set up for ACB 10

[nicksev172]

My Caterham has been set up for Avon ACB 10 tyres and need new ones. As I understand it, when a Caterham is set up with theese tyres that is all that should be used? The problem I have is that in May Im going to the 'ring and know theese tyres arn't the best in adverse weather (ie are dangerous!) so I was wondering if there are any alternatives that I could get that dont need the setup changing but are good if the weather turns bad?

[Red Seven]

nicksev172 said:

My Caterham has been set up for Avon ACB 10 tyres and need new ones. As I understand it, when a Caterham is set up with theese tyres that is all that should be used?

ACB10's are crossplies and require less camber than radials.

nicksev172 said:

The problem I have is that in May Im going to the 'ring and know theese tyres arn't the best in adverse weather (ie are dangerous!)

The difference between wet and dry with any tyres is much greater in a Seven than a tin top!

nicksev172 said:

so I was wondering if there are any alternatives that I could get...

CR500's offer about the best compromise between wet and dry performance

nicksev172 said:

.... that dont need the setup changing but are good if the weather turns bad?

Ah, that's the tricky bit!
You don't say what sizes of ACB10's you have, or anything else about the specification of your car.


I'm sure there will be a few who will say that CR500's work just fine on ACB10 settings, but if you push cr500's on track with ACB10 setings, then you'll wear the outside edges off the tyres.

If your ride height at the front is already on the low side, then fitting CR500's will make it even lower, and you'll have a greater risk of sump damage.

However, if you don't need it until May, then you have plenty of time to get it sorted out. As long as it has adjustable ride height, then resetting it to suit different tyres should not be too expensive.

Tell us some more about the spec of your car.

[rubystone]

ACB10s are crossply tyres as you may know. I personally don't like them on the road as they tramline terribly...in fact if you are driving through Belgium to the Ring, the huge ruts in the Belgian motorways are downright dangerous to a Caterham shod with ACB10s IMHO.

ACB10s need less negative camber than radials and thus you may well have to change the de dion ears if you switch tyres, but to be honest, I have run ACB10s and CR500s on the same de dion ears and they seem quite happy.

So what tyres to use? IMHO Avon CR500s - they are a good wet weather tyre for trackdays and whilst not as "sticky" as an ACB10 or slicks, they are nicely progressive on-track and ought not to get too hot at the 'Ring.

I haven't tried the Toyo 888s though, but hear good things about them too. I'd not waste time with Yoko 32s or 48s though as in my experience, they are not good tyres if the weather is bad.

Again, all IMHO and others may want to chime in with their own experiences.

[Tango7]

I'd go with the same suggestion as Ruby and replace the ACB10's with CR500's. Certainly as a general use road / track tyre they are very well suited. I have been on the Ring and tracks in the UK with CR500's and they have performed well across different conditions. Obviously in ideal conditions slicks and ACB10's will perform better if its dry and warm, but given that its not always like this, I would have your car set changed to radials (adjust settings at front and change de dion ears at the back if necessary), and then use the ACB10's when you can on the radial set up.

Speaking to Jonny at Bookatrack and commenting on the need for a different setup to optimise the ACB10's, the reply about most people not really being able to feel the difference would be quite true.

[nicksev172]

TBH I havent had the car long and havent driven it over winter or done a trackday yet.

The spec as I know it is '99 super 7 with vauxhall 2ltr redtop with SBD 250bhp kit that was 'flat floor' setup by ratrace motorsport with the ACB 10's on and It has adjustable bilstein shocks and adjustable anti-roll bars front and rear.

From what Ive read the ACB's are excellent on track as long as its dry so initially I was going to buy a new set of rears (the fronts are ok for now) and do some trackdays to get a feel for them and the car before I changed anything. But now Im going to the 'ring, hearing things like

" in fact if you are driving through Belgium to the Ring, the huge ruts in the Belgian motorways are downright dangerous to a Caterham shod with ACB10s IMHO."

it makes me think about getting a more suitable tyre and possibly changing setup.

So, considering this and from what you've all said I guess the best option is to get a full set of CR500's and get the setup changed to suit. Am I right in thinking the ACB's can be used on the same setup as the CR500's as a dry trackday tyre but just wont be optimised? This wouldnt be an issue for me as my limits are nowhere near the limits of the car with not having it long!

Many thanks for the replies

[Tango7]

nicksev172 said:

So, considering this and from what you've all said I guess the best option is to get a full set of CR500's and get the setup changed to suit. Am I right in thinking the ACB's can be used on the same setup as the CR500's as a dry trackday tyre but just wont be optimised? This wouldnt be an issue for me as my limits are nowhere near the limits of the car with not having it long!

Yes, that's about it.

My cars have been set up for CR500's and I swap on on to ACB10's or slicks when I do trackdays and the conditions are dry enough and you can have loads of fun. I have used ACB10's on the road (and have a new set waiting on some Barmby rims) and I find them very tiring to use on the road. The car tramlines terribly and follows any contours it can find which can be slightly disconcerting if you are going round a fast bend let alone a straight. In the rain, having them tramline and then with their light grooves going through standing water, I think you might have a few interesting moments. Put them on the track though and its like night and day as they are brilliant with a progressive nature so I'd keep them for track use until you have a bit more experience of the car

T

[Mars]

You can use ACB10s in the wet as long as you watch for standing water. On normal wet roads they retain their grip - in fact if it wasn't for their tramlining (in all weather) I might have stuck with them all the time.

Even in the wet you can get them up to temperature quite easily and as long as you remain "spirited" with your driving, they shouldn't cool. When warm/hot they're exceptionally grippy but the lack of deep tread blocks means they don't pump water away very effectively. If you read the road well, and take appropriate action when you encounter standing water, you should be OK.

If I were going to the ring, I'd probably keep the ACB10s on. Whilst it might mean a less relaxing drive there, you'll have more fun with them when you are on track.

[CatMatt7]

I too have recently bought a seven with ACB10's. The car is set up for them and I haven't found them too bad so far, certainly not as bad as I had heard they would be. I think that the right set up helps.

My previous seven was shod with AO48's so I was a little used to some tramlining now and again.

Haven't had the car long enough to have had the weather to have done any serious miles but have my first track day with the car this weekend.

Ideally my plan is to have two sets of wheels for track use and one for road use. That way I can get some cr500's for the road / wet track and keep slicks / ACB10's for track use. I have a couple of sets of ACB10's to get through.

Good luck

[nicksev172]

Mars said:

If I were going to the ring, I'd probably keep the ACB10s on. Whilst it might mean a less relaxing drive there, you'll have more fun with them when you are on track.

But if it was a wet weekend at the 'ring do you think the ACB's would struggle? It will be the first time on track in a Caterham and im just thinking I dont want to drive all that way and end up not being able to go out much because its sliding around unpredictably. From the couple of trackdays I have done in other cars it seemed that most of the Caterhams didnt go out when it started raining. Ive driven it in the rain and it didnt seem too bad but that was on the road at completely different speeds to on track.

[Mars]

nicksev172 said:

Mars said:

If I were going to the ring, I'd probably keep the ACB10s on. Whilst it might mean a less relaxing drive there, you'll have more fun with them when you are on track.

But if it was a wet weekend at the 'ring do you think the ACB's would struggle? It will be the first time on track in a Caterham and im just thinking I dont want to drive all that way and end up not being able to go out much because its sliding around unpredictably. From the couple of trackdays I have done in other cars it seemed that most of the Caterhams didnt go out when it started raining. Ive driven it in the rain and it didnt seem too bad but that was on the road at completely different speeds to on track.

Yes, Caterhams tend to be fair-weather cars for a number of reasons, notleast that they are light and need a bit of familiarisation before you can predict how they'll handle in the wet. They also need a setup your comfortable with, and you might only arrive at a comfortable setting after some time.

ACB10s are so much MORE than ANY other tyre you can use on a Caterham (short of slicks which are a step change again). You will only be able to drive them hard enough to keep them warm when you're 100% happy with your car. You get **there** after "time".

First time out? I'd err on the side of caution. They are great tyres but they need some learning, particularly in the wet.

Then again, would I have tried the 'ring when I was new to Se7ening? Dunno. Probably.

[BertBert]

Problem with driving to the ring and back as well as lapping the ring is will one set of tyres do the trip?

I don't think I'd do that. I'd not be going there with only one set of wheels. I'd probably have brand new CR500s for the journey and a set of ACB10s to use whilst there if it's nice weather (CR500's otherwse). If you are restricted to one set of wheels, then brand new CR500s would be the ones.

Bert

[fergus]

BertBert said:

Problem with driving to the ring and back as well as lapping the ring is will one set of tyres do the trip?

I don't think I'd do that. I'd not be going there with only one set of wheels. I'd probably have brand new CR500s for the journey and a set of ACB10s to use whilst there if it's nice weather (CR500's otherwse). If you are restricted to one set of wheels, then brand new CR500s would be the ones.

If you have the opportunity to trailer the 7 there, it gives you a lot more options with tyres. The 'Ring isn't too bad in the *damp* on ACB10s, but it's very slippery in places (even in the dry, where the surface has become very metalled), and CR500s will be the safe choice.

Don't attempt it in the wet on ACB10s. The off camber 2nd gear out of the schikane (corners after the hohenrain complex) caught me out there and the car span faster than Lord Goldsmith suggesting the Iraq war was legal.....

[nicksev172]

fergus said:

BertBert said:

Problem with driving to the ring and back as well as lapping the ring is will one set of tyres do the trip?

I don't think I'd do that. I'd not be going there with only one set of wheels. I'd probably have brand new CR500s for the journey and a set of ACB10s to use whilst there if it's nice weather (CR500's otherwse). If you are restricted to one set of wheels, then brand new CR500s would be the ones.

If you have the opportunity to trailer the 7 there, it gives you a lot more options with tyres. The 'Ring isn't too bad in the *damp* on ACB10s, but it's very slippery in places (even in the dry, where the surface has become very metalled), and CR500s will be the safe choice.

Don't attempt it in the wet on ACB10s. The off camber 2nd gear out of the schikane (corners after the hohenrain complex) caught me out there and the car span faster than Lord Goldsmith suggesting the Iraq war was legal.....

This is exactly what I've been thinking now have looked into it a bit more. Unfortunately, trailering the 7 there isn't an option and at this stage don't really want to buy a spare set of wheels, a new set of ACB's and a new set of CR500's. A couple of people I have spoken to said that they have worn a set of CR500's out in one trackday and Ive heard the ACB's are similar. So to drive over the ring, spend three days there and then drive back I'm not sure the one set of CR500's or ACB's will do it either.

Has anybody used Yokohama A021R or Avon ZZR tyres and if so how do they compare performance wise and durability?

I know they are much heavier so will reduce performance but will it make much of an impact to someone who isn't going to be pushing the limits of the car.

[Mars]

I know people who can destroy a new set of tyres in one trackday. On the other hand, on the Caterham-spec ACB10s (they're the hardest... least soft maybe), I can do 4000 miles including a couple of trackdays.

CR500s probably aren't as hardy on a trackday as ACB10s of a similar hardness. Put simply... there's more rubber touching the ground on an ACB10, so more to wear.

Something I overheard in a bar once :The ACB10 wear bars are a damning indication of your impending illegality. A sharp razor can eek the wear bar away making the tyre look as though it's got plenty of life left.

[rubystone]

I did half a Cadwell day (the wet part) on my CR500s and a whole day at Hethel in the dry last summer on them and there's plenty of wear left and I do drive the car hard too. We also put 80 or more laps on Caterham's DR300 last March at Brands Indy on a dry day and its CR500s stood up very well to the punishment. So I'd say you're fine with a set of new CR500s to drive ther and back and do the 'Ring

[jimmyslr]

I have driven to the Ring in a caterham, with no windscreen, a helmet, in the rain... This was with CR500s. I had more than enough "fun" on the wet roads as we neared the Ring. Seriously, there were many brown trouser moments as the back of the car stepped out at very modest speeds on the public road. I was travelling in convoy and all the Porsche blokes had to slow down for me and looked in the mirrors to see me sideways on the corner they'd just tootled around.

Caterhams in the wet have very modest grip. Fine to learn about that on a wide track, less fine on the road and not fun either. It can rain a lot and suddenly over there (well, anywhere actually), but Eifel mountains are famous for it. I would not contemplate driving to the Ring on ACB10s. It could be fine, but if it starts chucking it down just as you're on a twisty road with streams of water coming across an off-camber corner....

Call me Shirley, but that's my 2p

James