Quick question on tyres for bigger wheels

[thenick]

Right, got a new set of shiney wheels on order for the Chim, but I'm not sure if the same sort of tyres would still work well given the lower profile...

The perfect sizes for the wheels are apparently 215 40 17 & 235 40 18 though I could go to 225 40 17 on the front and 245 40 18 on the rear potentially... Would this be a good idea?

I currently run on Toyo T1-R's and have found them to be great tyres, though I shall be using the car less in the wet now and more for spirited driving on the road and track predominantly in the dry. Combined with the lower profile size, I'm not sure the Toyos would still be the best choice but I don't have any experience to go on so I was hoping someone on here might!

Tyres I've been looking at are as follows:

Toyo T1-R - Great but not sure I need the enhanced wet capability
Toyo R888 - Cost a fortune and not sure they're worth the extra
Bridgestone RE050A - Not sure about these but I'm told they're awesome and a better all around tyre than the Goodyear Eagle F1
Goodyear Eagle F1 GD03 - I have these on my Nissan and they seem to have nice characteristics, though I've heard tyre wear and wheelspin can be a bit of a problem with them (would tend to agree, but that may be the car and not the tyre in my experience!)
Dunlop SP9000 - Not used them but I know many TVR guys do and say good things about them
Avon ZZ3 - Can get these for a good price but have heard mixed reviews on them


So there seems to be far too many tyres out there to choose from, does anyone have any good advice they could share? The things I'm looking for predominantly are dry grip, progressive breakaway and reasonable wear. Not too bothered about wet handling, I'll just drive sensibly

[JR]

http://eu.goodyear.com/uk_en/tires/repository/Eagl...

[Johno]

Why have you gone for differen sized wheels front and rear ? Surely given the opportunity you'd want the same all round ?

Either way I reckon 17's are as far a you want to go, after that you're gonna need bloody good dampers

[T450t]

Without knowing what wheel widths you have purchased its hard to know what the correct parameters are for the tyres.

[thenick]

Sorry, wheel widths are 7" front and 7.5" rear... I prefer the look of smaller wheels up front hence the split sizes and am not bothered about a hard ride. I'll be sticking some uprated shocks on there soon along with bigger brakes so the damping can be sorted out then!

[JR]

You may have to re-think your rear tyre size: www.toyo.co.uk/productdetail.php?identity=products...

[thenick]

JR said:

You may have to re-think your rear tyre size: www.toyo.co.uk/productdetail.php?identity=products...

Why the rears?? They have both rear sizes, only 215 fronts though... I suppose I could go 235 front and 245 back, though I'm not sure they'd fit so maybe stick to 215 front 235 rear


Oooh I see - the rim width... That's odd, I was told ideal size as 235 rear...???

Edited by thenick on Monday 19th May 17:24

[T450t]

thenick said:

Sorry, wheel widths are 7" front and 7.5" rear... I prefer the look of smaller wheels up front hence the split sizes and am not bothered about a hard ride. I'll be sticking some uprated shocks on there soon along with bigger brakes so the damping can be sorted out then!

7" x 17" 215 tyre width

71/2" x 18" 225 tyre width

[Johno]

So you've bought wheels where you're going to have to run thinner tyres than you would with say 16" wheels all round to get a stiffer ride ?



Can you change the order for 8" width being wary of the offset ?

[thenick]

That's a bit odd...! Well I currently run 225s at the back, so that would be the same size tyre, but the rim would be wider and the profile less... I don't really know much about tyres but wouldn't the contact patch be stretched wider given the wider rim if I was to use that width tyre? I thought about an 8J rear but I don't think a 7.5J fits on the front, so I'd end up with more grip at the back than the front which would introduce understeer wouldn't it?

[Chimjunkie]

JR's link was to point out that with 40 or even 35 (which i run) profile on the rear your rim must be a minimum of 8J. To maintain same rear wheel diameter you need to run 245/35ZR18. I run this but feel the toyo is a bit too soft for 35 profile. Watch out for rim bashing on the potholes!

[JR]

Chimjunkie said:

JR's link was to point out that with 40 or even 35 (which i run) profile on the rear your rim must be a minimum of 8J. To maintain same rear wheel diameter you need to run 245/35ZR18. I run this but feel the toyo is a bit too soft for 35 profile. Watch out for rim bashing on the potholes!

Yes, really TVR should have fitted 8.5" rims when they went from 225 to 245 wide tyres.

thenick said:

That's a bit odd...! Well I currently run 225s at the back, so that would be the same size tyre, but the rim would be wider and the profile less... I don't really know much about tyres but wouldn't the contact patch be stretched wider given the wider rim if I was to use that width tyre? I thought about an 8J rear but I don't think a 7.5J fits on the front, so I'd end up with more grip at the back than the front which would introduce understeer wouldn't it?

Hold on. This is turning into an 'I wouldn't have started from here' type answer. There's no perfect answer since people's motoring requirements vary.

You've got the wheels so, similar to your original idea, how about fitting 215/40/17 front (they were 205/60/15, 205/55/15 or 225/50/15 originally) and 225/40/18 rear (they were 225/50/16, 225/55/16, 235/50/16 or 245/45/16 originally) which would be fine IMHO. Narrow rims and tyres are lighter, cheaper and less likely to tramline. If you want to track the car a lot buy a cheap set of 16" all round and have fun with 888s.

Edited by JR on Monday 19th May 19:52

[thenick]

Hmm thanks for the info JR, I'll have a word with the company supplying the rims and see whats what... I'll be keeping the Imolas anyway so I could very well put some R888s on those for track use, depends how much I do really. I have a couple of trackdays booked this summer so I'll see how it goes!

[Groomvroom]

My SP12s came with 215 40 17 front and 245 35 18 rear, both still look a bit skinny to me, no idea what the rim widths are but the tyre fit the rim very well.