New tyres and geo - sizes?
New tyres and geo - sizes?
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Discussion

T40ORA

Original Poster:

5,177 posts

248 months

Sunday 20th June 2010
quotequote all
As the title says, I need new rubbers and a geo set up. So I thought that I would take the opportunity to think, once again, whether or not it is worth changing the size of the boots.

My main reason for considering this is that it might offer a bit more protection to the edges of the wheel rims and I may get slightly better traction at the rear.

However, I don't want to foul the arches in any way or compromise the handling - I've heard that fatter fronts can cause more tramlining. "Time's is 'ard" at the moment, as they say, so I can't afford to also uprate the shocks and bushes (bloody tyres and insurance renewal will see to that).

Anyone on here got any good advice, or experience of changing sizes?

TIA

fredd1e

783 posts

249 months

Sunday 20th June 2010
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From a few searches on here and from checking out cars with SP12's there seems to be a few who have fitted 255/35x18 rears and 225/40x18 fronts. Whether or not these will work on your car probably depends on what setting /state your spings and shocks are, from you pic your're probably on factory Bilsteins which seem to ride a little higher than the old HB shocks and springs. But I doubt theres a definite answer until you try.
You could check how much clearance you have between top outside shoulder of rear tyres and arch to see if theres leeway for a wider (though smaller diameter) tyre, and for the front check out how much clearance the inner/outer shoulders of the front tyres have at full lock.
This site http://www.rimsntires.com/rt_specs.jsp gives a good comparison between different tyre sizes, but remember its only a guide and often the same size from different manufactures can have different physical sizes when compared.

-Jamie-

175 posts

217 months

Friday 25th June 2010
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255/35/18 rear and 235/35/18 front? or run 40's front and back, seems to give a slight better ride with the bigger profile
Very much doubt it will scrub under compression but could always raise it alittle
If i remember correct it has nitrons

Edited by -Jamie- on Friday 25th June 18:00

T40ORA

Original Poster:

5,177 posts

248 months

Friday 25th June 2010
quotequote all
NOt sure what it's running Jamie, they're still factory fit; would Nitrons have been standard or Billies?

grumbledoak

32,571 posts

262 months

Friday 25th June 2010
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Nitrons weren't factory fit, for sure. Plenty of threads here with owners upgrading.

TVR_owner

3,349 posts

220 months

Saturday 26th June 2010
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T40ORA said:
NOt sure what it's running Jamie, they're still factory fit; would Nitrons have been standard or Billies?
Stick with standard profiles - lots of agro messing about with profiles for very little or no reward. You car may have had billies from the factory it being a late car and all that. If not Billies, it would have been Harvey Bailey.

T40ORA

Original Poster:

5,177 posts

248 months

Saturday 26th June 2010
quotequote all
More than just geo set up agro John? If I can protect the wheels a bit it would be good, but not if, as you say, it's loads of agro.

willtvr

1,099 posts

226 months

Saturday 26th June 2010
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T40ORA said:
More than just geo set up agro John? If I can protect the wheels a bit it would be good, but not if, as you say, it's loads of agro.
Would have thought the best way to protect the rims would be to stay away from kerbs Lee confused

T66ORA

3,474 posts

286 months

Saturday 26th June 2010
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I don`t normally disagree with John,but I have used 255/35x18 on the back of my Tamora for the last 4 years, no problem with clearance/scrubbing, no problem with the Speedo,they lower the ride height by 5mm and they lower the gearing slightly, so in theory, should make it slightly quicker through the gears.You will get slightly better grip, in the dry. Going to 35 profile i was expecting the ride to suffer slightly, but in the end i couldn`t tell any difference.
When i need to replace the rear tyres again i will be buying 255/35s again.
I run standard 225/35`s on the front.

T40ORA

Original Poster:

5,177 posts

248 months

Saturday 26th June 2010
quotequote all
willtvr said:
T40ORA said:
More than just geo set up agro John? If I can protect the wheels a bit it would be good, but not if, as you say, it's loads of agro.
Would have thought the best way to protect the rims would be to stay away from kerbs Lee confused
Crikey. I never would have thought of that Ian.

TVR_owner

3,349 posts

220 months

Sunday 27th June 2010
quotequote all
T66ORA said:
I don`t normally disagree with John,but I have used 255/35x18 on the back of my Tamora for the last 4 years, no problem with clearance/scrubbing, no problem with the Speedo,they lower the ride height by 5mm and they lower the gearing slightly, so in theory, should make it slightly quicker through the gears.You will get slightly better grip, in the dry. Going to 35 profile i was expecting the ride to suffer slightly, but in the end i couldn`t tell any difference.
When i need to replace the rear tyres again i will be buying 255/35s again.
I run standard 225/35`s on the front.
Seems like you already knew the answer Lee. Take it you had the geo revised last time you fitted the new boots to account for the change in rear ride height.

T40ORA

Original Poster:

5,177 posts

248 months

Sunday 27th June 2010
quotequote all
TVR_owner said:
T66ORA said:
I don`t normally disagree with John,but I have used 255/35x18 on the back of my Tamora for the last 4 years, no problem with clearance/scrubbing, no problem with the Speedo,they lower the ride height by 5mm and they lower the gearing slightly, so in theory, should make it slightly quicker through the gears.You will get slightly better grip, in the dry. Going to 35 profile i was expecting the ride to suffer slightly, but in the end i couldn`t tell any difference.
When i need to replace the rear tyres again i will be buying 255/35s again.
I run standard 225/35`s on the front.
Seems like you already knew the answer Lee. Take it you had the geo revised last time you fitted the new boots to account for the change in rear ride height.
That's not me John! That's Tony (T66 ORA rather than T40 ORA).

TVR_owner

3,349 posts

220 months

Sunday 27th June 2010
quotequote all
Sorry Lee, advice stands.

T40ORA

Original Poster:

5,177 posts

248 months

Monday 28th June 2010
quotequote all
T66ORA said:
I don`t normally disagree with John,but I have used 255/35x18 on the back of my Tamora for the last 4 years, no problem with clearance/scrubbing, no problem with the Speedo,they lower the ride height by 5mm and they lower the gearing slightly, so in theory, should make it slightly quicker through the gears.You will get slightly better grip, in the dry. Going to 35 profile i was expecting the ride to suffer slightly, but in the end i couldn`t tell any difference.
When i need to replace the rear tyres again i will be buying 255/35s again.
I run standard 225/35`s on the front.
No more pothole damage on the 35s at the rear? A bit thinner so less protection than the standards.

Madmatt V8

478 posts

221 months

Tuesday 29th June 2010
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Sorry to jump in on this but I am also considering going to 255s for more grip than anything else. Some have no problems and some have some scrubbing, must all be down to the set up I guess. I have been thinking hard about going onto toyo 888's but can't find them in 225/35?! Does everyone go 235/35 on the front or 225/40 with the toyos?

GT TVR

1,627 posts

311 months

Tuesday 29th June 2010
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Like discussed various times before: go for Toyo R1R's, 255/35 rear, 225/40 front.
Or leave them as standard.

Barry Ashcroft

1,958 posts

250 months

Tuesday 29th June 2010
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GT TVR said:
Like discussed various times before: go for Toyo R1R's, 255/35 rear, 225/40 front.
Or leave them as standard.
Thats what is fitted on mine.

Madmatt V8

478 posts

221 months

Tuesday 29th June 2010
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Sorry have not read them all. Why the R1R's over the 888's ? Sorry again for my ignorance lol

Barry Ashcroft

1,958 posts

250 months

Tuesday 29th June 2010
quotequote all
Madmatt V8 said:
Sorry have not read them all. Why the R1R's over the 888's ? Sorry again for my ignorance lol
R1R's much better in the wet

T40ORA

Original Poster:

5,177 posts

248 months

Tuesday 29th June 2010
quotequote all
Did I hear that one of the Toyo types have softer sidewalls so you get more wear on the edges of the tyres?