Exact wheel spec

[Chris71]

Hi,

This might be a trivial question, but what dimensions, front and back, would I need to order a set of 16" wheels for my Chimaera?

I presume it's PCD/hub type (standard I presume), offset, diameter and width? ... Is there anything else (if I order it as a generic wheel, as opposed to ordering from a TVR supplier)?

Cheers,

Chris

[JR]

Depends upon your exact tyre spec - not a trivial decision.

[Chris71]

Oh, that's a whole can of worms... I know I want 16" wheels (I'd prefer 15s on the front, but the ever decreasing choice of performance tyres in 15" means 16s sound like the best compromise) and I assumed that one wheel width (and diameter) would serve for a range of different tyre sizes?

Anyway, standard for a non-PAS car would, I believe, be:
205/55/15 FRONT
225/50/16 REAR

As I bought it, the car has:
225/40/18 FRONT
235/40/18 REAR

...And most of the PAS cars have 225 front and 245 rear.

So the likely range is 205 to 225 front and 225 to 245 rear. Would it be possible to cover that whole range with two pairs (narrower front pair and slightly wider rear pair) perhaps?

[JR]

Chris71 said:

So the likely range is 205 to 225 front and 225 to 245 rear. Would it be possible to cover that whole range with two pairs (narrower front pair and slightly wider rear pair) perhaps?

You can do that but it would be a compromise. 225f&245r would be great for summer track days with 7.5fET30&8.5rET35 rims for example. If you want the flexibility then you'd be better to move down half an inch on each although you could fit the smaller tyres anyway. What you really want is a 215f as per original spec for the chassis but no-one makes one in 16" AFAIK, that's life, lol.

BTW PCD is the Ford 3" square and you need the centrebore dim which I can't remember.

[Chris71]

There's a big choice in 215/55 r16, none in 215/50 and a few in 45 and 40% profiles (including the T1Rs, which I'm told might work well in very low profile due to their soft sidewalls?)

What's the OEM non-PAS 500 rear tyre width (to go with the 215 fronts)?

Back to the wheels, looking at the Pro Race 1.2 range, presumably I'd want:
front: 7x16" 4-stud ET25
rear: 7.5x17" 4-stud ET35

(They don't do the 7.5" x 16 and some argue that keeping the larger rear wheels maintains the proportions anyway?)

Edited by Chris71 on Thursday 30th December 21:33

[JR]

Chris71 said:

There's a big choice in 215/55 r16,

It's a little large though and

Chris71 said:

40% profiles

Are very small so what you want is

Chris71 said:

a few in 45

but I don't know any, eg no T1-Rs. Which tyre were you thinking about? This: http://www.toyo.co.uk/productdetail.php?identity=p... in 215/50/16?

Chris71 said:

What's the OEM non-PAS 500 rear tyre width (to go with the 215 fronts)?

AFAIK the 500s only ever had a 245 rear. The PAS/non PAS is a bit of a red herring BTW.

Chris71 said:

Back to the wheels, looking at the Pro Race 1.2 range, presumably I'd want:
front: 7x16" 4-stud ET25
rear: 7.5x17" 4-stud ET35

From that range you'd want the 8x17ET33rear&7x16ET25front

Chris71 said:

They don't do the 7.5" x 16 and some argue that keeping the larger rear wheels maintains the proportions anyway?

Pity and yes. Remember that there are so many aspects to choosing wheels and tyres: performance, cost comfort, availability, appearance that there are many best answers depending upon the weighting that any given onwers places on these and other considerations. Good luck. (BTW FWIW I wouldn't lose any sleep about adopting the 8x17.)

[Chris71]

Black Circles has Yokohama Advan A043/Neova AD08s, Continental Premium Contact 2s, Bridgestone RE040, Pirelli P7s and a couple of other options in 215/45 R16. I can't say I have any experience of these, so they may not be ideal, but they do exist.

Out of interest, how much reduction in steering weight do you think will come from reducing the radius alone? It really is very heavy on the 18s, but the radius contributes to the overall tyre area as well as the width, so maybe it'll lighten up even on 225s if I go down to a 16? Might be wishful thinking...

What range of tyres could I run on an 8" rear wheel? Could I, for example, go back to the 225, if I want to run a 205/225 combo?

[EggsBenedict]

I went with 225F and 255R. TR1s

16" on front, 17" on rear because I wanted to retain the proportions. Think this looks best of the combinations I've seen. Went with compomotive MO6 from these guys http://www.performancealloys.com/wheel-details.asp... Reasonable prices and knew what they were on about. Give them a ring - they were friendly enough...

[Cider Andy]

JR said:

AFAIK the 500s only ever had a 245 rear. The PAS/non PAS is a bit of a red herring BTW.

I don't know what other 'standard' wheels and tyres were fitted over the years, but according to page 45 of the Owner's Handbook published by TVR in January 1997:

Wheels and tyres.

Front: 15" x 7J aluminium alloy wheels fitted with Bridgestone SO2 - 205/55 ZR low profile tyres (Chimaera 500 with P.A.S. 225/50)

Rear: 16" x 7.5J aluminium alloy wheels fitted with Bridgestone SO2 - 225/50 ZR low profile tyres.

[Chris71]

Does anyone know the comparative weights of the usual alloy choices? I'm thinking something like the Team Dynamics Pro Race 1.2 and I know they're significantly lighter than the OEM units, but wondered how the other after market 16/17" wheels compared.

Going with 16 front, 17 rear I think.

Post-drive edit:

Just took the car out for a brief potter. As you can probably tell I'm having something of a dilema here. I'm wary about 'under-tyring' something with the Chimaera's grunt, but also reluctant to turn it into a bicep builder. But I hadn't actually driven it for a while, so I decided to take it round the proverbial block, and two things sprung to mind:

Firstly, it's maybe not quite as bad as I make out. Although it's definitely on the heavy side a degree of MTFU could be applied.

Second, and far more surprising, was something that dawned on me while shuffling it back into the garage: I think the steering is actually lighter at manoeuvring speeds... I reckon the 'weight' on this particular example might be due to those sodding 18" wheels and their gyroscopic effect.

Edited by Chris71 on Tuesday 4th January 16:00

[JR]

Chris71 said:

Yokohama Advan A043/Neova AD08s, Continental Premium Contact 2s, Bridgestone RE040, Pirelli P7s and a couple of other options in 215/45 R16.

The answrs to most of your points is going to be dependant on what you want from the car. A043s and AD08s are good trackday tyres, the latter being more road orientated; didn't know that they did CPC2s in that size and don't know whether they would work well on a light high performance car - speak to Continental? RE040s may work well, P7s were the default choice in the 70s, I suppose that they have been developed but I wouldn't bother.

[JR]

Chris71 said:

Out of interest, how much reduction in steering weight do you think will come from reducing the radius alone? It really is very heavy on the 18s, but the radius contributes to the overall tyre area as well as the width, so maybe it'll lighten up even on 225s if I go down to a 16? Might be wishful thinking...

Quite a lot, not just wishful thinking.

[JR]

Chris71 said:

What range of tyres could I run on an 8" rear wheel? Could I, for example, go back to the 225, if I want to run a 205/225 combo?

215/45 would be your normal narrowest for an 8" wheel and 245/40 the widest.

[JR]

Cider Andy said:

JR said:

AFAIK the 500s only ever had a 245 rear. The PAS/non PAS is a bit of a red herring BTW.

I don't know what other 'standard' wheels and tyres were fitted over the years, but according to page 45 of the Owner's Handbook published by TVR in January 1997:

Wheels and tyres.

Front: 15" x 7J aluminium alloy wheels fitted with Bridgestone SO2 - 205/55 ZR low profile tyres (Chimaera 500 with P.A.S. 225/50)

Rear: 16" x 7.5J aluminium alloy wheels fitted with Bridgestone SO2 - 225/50 ZR low profile tyres.

I have heard of lower cc cars with 225 all round but not 500s. It may have been in the handbook but did any ever get that fitted in production? A footnote really - fit what works best for you.

[JR]

Cider Andy said:

Rear: 16" x 7.5J aluminium alloy wheels fitted with Bridgestone SO2 - 225/50 ZR low profile tyres.

Also note that the rear rims are sized for 215 or 225 tyres and not 245.

[JR]

Chris71 said:

I'm thinking something like the Team Dynamics Pro Race 1.2 and I know they're significantly lighter than the OEM units

So what are the weights? The Spiders on later models are weak and heavy but for Chims I'd be surprised if the 15" wheel was significantly heavier than a 16" PR1.2, similarly for the rear.

[MischaVisserv8]

first best wishes to you all for 2011!


hello chris71;

ref yr post maybe i can help a bit?

two years ago i have changed the wheels from my griff for team dynamics pro race 1.2 (unfortunately with the nasty letters but you can order them without - pro race 1.2S if you want).

only disadvantage rear wheels look different but not with 16 / 18 inch i believe only 17 inch?

i went for the following sizes;

front 205 - 50 - 16zr with toyo's / 7 x 16 et 25 / 63,3 ford sierra bore
rear 235 - 45 - 17zr with toyo's / 8 x 17 et 33 advice from team dynamics!

the weight of the wheels with tyres is a lot lighter than the original estorils with tyres!

i don't know exactly but i think almost 0,5 - 1kg each side but not for sure but significantly lighter!!


good luck

cheers

mischa

[SILICONE KID]

I still have these sitting in the garage 2 of Pro Race 1.2 17" 4x108 ET 25 7.5J Tyres Falken 452`s 215/40/17 Both like new..

[JR]

MischaVisserv8 said:

i have changed the wheels from my griff for team dynamics pro race 1.2 ...
front 205 - 50 - 16zr with toyo's / 7 x 16 et 25 / 63,3 ford sierra bore
rear 235 - 45 - 17zr with toyo's / 8 x 17 et 33 advice from team dynamics!

the weight of the wheels with tyres is a lot lighter than the original estorils with tyres!

i don't know exactly but i think almost 0,5 - 1kg each side but not for sure but significantly lighter!!

Pro race in those sizes is about 7.2kg and 9.1kg AFAIK, say double that weight with tyres. So wheel weight saving is about 10% and overall is about 5%. Probably about cancels out the increase in inertia.

[MischaVisserv8]

hello jr,

driving with the set feel's also very light-footed and
handling is also perfect altough i'm thinking about upgrading to 17 / 18 but not for sure yet.

brgds
mischa