Same size all round

Same size all round

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QBee

Original Poster:

20,957 posts

144 months

Thursday 26th February 2015
quotequote all
Yes, I always recommend people to have bigger rear tyre diameters than front.

But then I got to wondering if anyone had run a Chimaera on track or fast road with four wheels/tyres the same size, and how it felt?

Only actual experiences please guys.


ClassiChimi

12,424 posts

149 months

Thursday 26th February 2015
quotequote all
I ran Peters 17's all round at Marham Anthony, compared to the original 15/16's
I'd say I had less bite turning in on the fronts with the 17's but then I'd not really set the car up or played with tyre pressures,, although I had the shocks virtually rock solid. Remember it's smooth and fast there Anthony,,
My instinct is to go 17f 18r but with a bit of ride height adjustment etc I reckon the balance is still really good when running "same all round "
Al

QBee

Original Poster:

20,957 posts

144 months

Thursday 26th February 2015
quotequote all
I run 17s all round now, but with bigger tyres on the rear than the front to make the 20-25mm difference in diameter.

What I mean, to clarify, is 17 inch wheels and the same size tyres all round.

ClassiChimi

12,424 posts

149 months

Thursday 26th February 2015
quotequote all
I'm a bit odd though!!!!
I like a rock hard chassis that's totally flat and no give,,,
Slides easier but if you ram the fecker into the corner you'll still Roll and get on the outside edge of the tyre unless you have full race springs on,

I think you have to go pretty damn hard to provoke the front into understeer,
I just wondering wether the brakes work better on a smaller wheel as it's travelling faster so heats the disc quicker,,,
Now't to do with size, heat and pad composition is what stops you I reckon, big powerful calipers can't do any harm though!
Just thinking aloud,,,
Many ways to get the same results maybe !


ClassiChimi

12,424 posts

149 months

Thursday 26th February 2015
quotequote all
Ah, got you.
What so run the same size on the fronts as on the rears,
To big and wide maybe, lack of bite on the fronts,, not enough weight on the footprint of the fronts but I sure it an be made to work, soft compound tyre and a bit more weight over the front and it might be the biz,,, are you still trying to stuff Peter,, hahahah, I love it, Hahahah .

QBee

Original Poster:

20,957 posts

144 months

Thursday 26th February 2015
quotequote all
Well, I have gone to big front brakes with racing pads.

I have been offered a set of tyres all the same size. Just wondering how they would drive/handle? I know of one guy who finds it fine, just wanted more opinions

brett84

1,291 posts

153 months

Thursday 26th February 2015
quotequote all
is yours PAS? Mine feels better now i've switched from 225 to 215 on the front but maybe thats partly because it hasn't got power steering.
If the geo is done after fitting same size wheels, it wouldn't have and ill effect over running larger rears would it?

SILICONEKID345HP

14,997 posts

231 months

Thursday 26th February 2015
quotequote all
brett84 said:
is yours PAS? Mine feels better now i've switched from 225 to 215 on the front but maybe thats partly because it hasn't got power steering.
If the geo is done after fitting same size wheels, it wouldn't have and ill effect over running larger rears would it?
Do those 215/45/17 catch on the front ? Mine caught on full lock and hard braking . They did feel better than the 215/40/17.

Be careful on some of the load ratings ,it could invalidate your insurance .

QBee

Original Poster:

20,957 posts

144 months

Thursday 26th February 2015
quotequote all
SILICONEKID345HP said:
brett84 said:
is yours PAS? Mine feels better now i've switched from 225 to 215 on the front but maybe thats partly because it hasn't got power steering.
If the geo is done after fitting same size wheels, it wouldn't have and ill effect over running larger rears would it?
Do those 215/45/17 catch on the front ? Mine caught on full lock and hard braking . They did feel better than the 215/40/17.

Be careful on some of the load ratings ,it could invalidate your insurance .
I really like mine (with PAS) on 215s all round. 40s on the front, 45s on the rear. Seems to have more grip than with 235 rears, oddly, and the fronts corner well.

mk1fan

10,516 posts

225 months

Thursday 26th February 2015
quotequote all
Well the two best handling TVRs have the same size tyres front and back.

That said, with the torque delivery of the RV8 perhaps wider rear tyres is a sensible step.

ClassiChimi

12,424 posts

149 months

Thursday 26th February 2015
quotequote all
If you play with your geo you'll get most things to work on a balanced car,,,
I'd be worried about locking the front brakes on the roads, tyre too wide and not enough give, just slide away rather than squatting and digging into the Tarmac, ride height change and more bias to the front might make the car a sticky thing,,

phazed

21,844 posts

204 months

Friday 27th February 2015
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Grahamm runs 255/40/17s all round on track on his cerb.

Don't sags run that size?

QBee

Original Poster:

20,957 posts

144 months

Friday 27th February 2015
quotequote all
phazed said:
Grahamm runs 255/40/17s all round on track on his cerb.

Don't sags run that size?
I'm not as Max Power as that - the tyres I have been offered are 225/45 17. I can see I just might have front catching issues on full lock, so need to do some thinking as I don't presently have any 225s to try. And I still have to persuade myself that 225s won't be worse than 215s.......I agree, why change, but my 215s will eventually wear out,. especially the way I drive on track

While tryping this I have realised I am thinking in sets of 4 - but I could always use my present 215s, both front and rear, as the fronts for 2 sets, and use the offered set of 4 as my rears for two sets of tyres.....

swanny71

2,853 posts

209 months

Friday 27th February 2015
quotequote all
QBee said:
I'm not as Max Power as that - the tyres I have been offered are 225/45 17. I can see I just might have front catching issues on full lock, so need to do some thinking as I don't presently have any 225s to try. And I still have to persuade myself that 225s won't be worse than 215s.......I agree, why change, but my 215s will eventually wear out,. especially the way I drive on track

While tryping this I have realised I am thinking in sets of 4 - but I could always use my present 215s, both front and rear, as the fronts for 2 sets, and use the offered set of 4 as my rears for two sets of tyres.....
Picked up my new RL7's from Quinny at the weekend and we got talking tyres, as you do. He'd tried 225/45/17 Federal's on the front of his Griff and had catching issues but the same tyres on his mates Chimp were OK - so might be alright.

I've gone conservative with tyre sizes for the RL7's because of potential arch catching issues, ordered 215/40/17 and 245/40/17 Conti Sport Contact 3's. Excellent tyre that I've done tens of thousands of miles on (old M3, current 130i and also the Chim).

My only concern is stretch on the front with an 8j rim but I'm lead to believe 215/45/17 would have been no better (for stretch)

Did look at 225/35/17 but tyre choice was crap and reduction in circumference was significant.

Ps. Thanks for your experiments with tyre sizes on the other thread thumbup

jesfirth

1,743 posts

242 months

Friday 27th February 2015
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You can comfortably fit 225 45 17 on the front and at a squeeze 255 40 17 on the rear. It is well balanced at least on mine.