When to go for bigger tyres.

[JamesZ]

I'd always planned to avoid starting a thread on tyres, but I've just been on the phone to Scholar, who are building my new zetec and there was a slight problem with the power: I'd asked for 185, but when they had it on the bench this morning it came out at 213! 😬 😬 😬

 

Alongside the hassle of having to tell the insurers that the power is more than expected, I am also wandering whether I should put some slightly bigger rubber on the back than my 185 70 13s.

 

Is it going to be more slippery than the cars Caterham use for their slalom days on a teflon coated ice-rink, or will it still be driveable with caution?

 

James

[Manxseven]

James,

 

Was not your figure of 185 bhp at the 'wheels'?

 

The 213bhp is at the Flywheel, so that's not far off the 185 at the wheels.

 

Your not live axle are you?

 

 

 

 

 

Edited by - Manxseven on 13 Nov 2007 15:24:05

[Stationary M25 Traveller]

Is that live axle or lively axle

 

7 related photos

[Sheds Moderator]

I think that for insurance purposes your car generates approx 199 bhp. You have set a 6000rpm redline, of course.

 

The other 180-199 bhp (ahem) boys tend to fit 205s at the back as far as I know.

[JamesZ]

Was 213 on the bench, it's not in the car yet - but then it was only meant to be 185.

 

And yes - it is live axle - but English, not Ital - hopefully it'll cope.

 

James

[Manxseven]

Ah full English 😬 cope with loads of power 😬

 

enjoy

[Big Brother]

I've run a 2l Zetec for a while now.

Yes, the rear end will be a lot more lively than your crossflow!

However, once you get used to it, it's not too bad.

You need to learn how to drive the car again

Mine is more of a "slowly round the corners then as soon as the road is straight....nail it" type of car 😬

 

I'm about to swap from 185/70R13's to 205/60R13's on the rear with the aim of getting a bit of the rear end grip back.

 

 

Steve

 

 

SE7EN-UP!

---

_{Build a man a fire, and he'll be warm for a day.}

Set a man on fire, and he'll be warm for the rest of his life!

---

 

[Shaun_E]

When I upgraded from 135 bhp to 227 bhp, I found that 185s were a little lacking in the traction department (wheelspin in 3rd if being brutal ) so moved to 205s. This improved traction but also introduced some unwelcome understeer which it took a bit of set-up tweaking to eliminate. So, if you bear that in mind, a move up in tyre size is probably a good idea at that power level.

 

Yellow SL #32 - member of Drowned Rat Racing

[Mickrick]

You could even go to 245/50 X 13's in a CR500 (8 to 10 inch rim)

 

The older I get, the faster I was!

[JamesZ]

Sounds like a step up might be a wise choice then.

 

Next Numpty question. Will my standard 13" 1996 caterham minilites take a 205 - or do i need wider wheels too?

[Mick Day]

Standard 6 x 13" will be OK for 205/60/13.

[Julian Thompson]

Yes, and remember that if you DO go up to the wider wheels like 8's or 10's with the 205 section tyres you will get less sidewall flex - and poorer traction on bumpy roads with the Live Axle.

 

I have found that the 6 or 6.5 wheels with the 205's works really well on the road with a Live Axle - you get a much smoother ride!!

 

On the track it's fine on the wide ones.

[Mickrick]

Recomended rim size for 205/55 X 13 CR500's is 6.5 to 8.5 inches.

 

The older I get, the faster I was!