Wheel/Tyre cock up.

[STE VR]

I've just fitted some 7x17" Jorden R's. The tyre people said i could only fit 215/45/17 max (i have 215/40/17 on front and am happy with them) I needed the car in a hurry so reluctantly agreed. I have to say they look bloody awful on the rear. Does anyone know if i can put 235/45/17 on rear or what alternatives I have???? Many thanks, Steve

[300bhp/ton]

STE VR said:

I've just fitted some 7x17" Jorden R's. The tyre people said i could only fit 215/45/17 max (i have 215/40/17 on front and am happy with them) I needed the car in a hurry so reluctantly agreed. I have to say they look bloody awful on the rear. Does anyone know if i can put 235/45/17 on rear or what alternatives I have???? Many thanks, Steve

Only a 215 section on a V8 sports car???

Aren't the stock tyres 235 or something?? Anyhow, as long as you've not alter the offset so they tyres foul the body work you should be able to run at least the same width as before. And as long as you haven't made the over wheel height any greater or buy too much.

I don't want this to sound patronising so please excuse anything which is, I'm just trying to help, lol

Tyre sizes. The profile height, the second set of numbers are a percentage of the width.

So in your case a 215/40 means the sidewall height is 40% of 215mm. Which is 86mm.

From here we can get an idea of how tall the tyre is (only an idea, as different makes vary a little due to lug/tread design and other factors).

So a 17" rim, + the sidewall height twice (for the top and bottom of the tyre).

25.4mm to an 1"

431.8mm = 17" + 86 + 86 = 603.8mm total height


A 215/45 R17 would be:

431.8 + 96.75 + 96.75 = 625.3mm

Sidewall height of 96.75mm

So it would be about an 1" taller overall with about 1/2" chunkier sidewall. It would look better, but it's still way too skinny IMO.

I'm not sure but personally I'd want a 235 or maybe even a 245 width tyre on the back of a V8 TVR. But even with a low profile percentage, you'll still have a chunkier tyre.

However a 235/40 R 17 would only have a 94mm side wall. So actually wouldn't be as tall as a 215/45 by 3.5mm overall. Personally I'd have thought this a better size to look at.

[STE VR]

Trust me, i need patronising sometimes!!!!! .... Many thanks for the info, its very useful. I think i will heed your advice and go with 235/40/17 as long as they will sit ok on a 7J rim. The 215 rears are just far too poor handling wise. Oh well thats what i get for being impatient.. Cheers, Steve

Edited by STE VR on Saturday 4th October 10:18

[300bhp/ton]

STE VR said:

Trust me, i need patronising sometimes!!!!! .... Many thanks for the info, its very useful. I think i will heed your advice and go with 235/40/17 as long as they will sit ok on a 7J rim. The 215 rears are just far too poor handling wise. Oh well thats what i get for being impatient.. Cheers, Steve

Edited by STE VR on Saturday 4th October 10:18

With such a low profile and a comparatively wide tyre you might struggle on a 7J alloy.

A taller sidewall would allow the width, but might be an oddball size and hard to buy, plus it'll make the tyre taller.

Only other option is to drop the down on the width so maybe a 225/45, either that or look at buying a wider alloy.

A useful source for such info is BFG's website. They carry a table of stats for most tyres which give you width, profile, over height and rim widths.

http://www.bfgoodrichtires.com/specs/g-force-t-a-k...

Profile has almost as much bearing on rim width as the width of the tyre does. For example you can run a 225/55 on a 6J rim, but a 225/45 requires a 7J rim.

[STE VR]

Have spoke to a few people and tyre places... I've gone for the 235/45/17 as they all say they will go on a 7J as long as they don't foul the car which i don't think they will. I did have 225/55/16 which is 653mm tall, the 235/45/17 are 643mm tall(i think).. but it will probably all end in tears as usual when i start messing with her!!! thanks for the advice.

[S7Paul]

And don't forget that fitting any tyre with a different overall diameter to the OE fitment will affect both speedo and mileometer accuracy.

[STE VR]

I've never deemed either of them to be accurate on a TVR anyway

Edited by STE VR on Saturday 4th October 11:47

[GreenV8S]

STE VR said:

Have spoke to a few people and tyre places... I've gone for the 235/45/17 as they all say they will go on a 7J as long as they don't foul the car which i don't think they will.

That's a very wide tyre for such a narrow rim. The rears are 7.5J as standard, are you aware you've gone for narrower rims which will need narrower tyres? They might look nice, but from the handling point of view probably not good news.

[300bhp/ton]

You can fit stretch a tyre to fit the rim, it's in fact quite a popular thing among the chav and in Europe. It's not my taste personally but it appears to be perfectly ok otherwise.

I say go for the 235 if the tyre shop is happy to fit it. Take a good look before you drive away and make sure you are happy.

I think you should be ok though

[GreenV8S]

300bhp/ton said:

You can fit stretch a tyre to fit the rim, it's in fact quite a popular thing among the chav and in Europe.

You *can* do, that doesn't mean it's sensible. All the tyre monkeys will care about is that it doesn't blow off the rim before you have paid for it, they won't have any idea what effect it will have on the handling. In some ways stretching a narrow tyre on a wide rim is better than the other way round. You probably won't have any problems in a straight line, but under hard cornering you are likely to find that the tread tends to pick up on the inside. This reduces the grip and can even cause the tyre to 'hop' sideways when it is heavily loaded. It's not really something you want to be doing to the back of a powerful rwd sports car, even if Kevin from your local tyre 'n' exhaust place reckons it'll be fine.

[STE VR]

300bhp/ton said:

it's in fact quite a popular thing among the chav and in Europe.

Oh cr@p please don't call me a 'chav'..... I don't have an option to change alloys at the moment but will do when funds allow. in the meantime I will just have take it easy going round bends. I use it everyday and don't tend to drive it that hard into corners. I still think it's a better option than the 215 width as if feels really poor at the backend. I do have a good friend who is fitting the tyres and he wouldn't knowingly give me a bum steer and has been honest in saying it's not the best situation but shouldn't have too many problems... Cheers, Steve

[steve-V8s]

GreenV8S said:

even if Kevin from your local tyre 'n' exhaust place reckons it'll be fine.

Thought he was called Wayne.

[lwt]

Don't know if this will help, but I run 245 width on the rear on std chim wheels (i.e. std offset) without any fouling etc. I think it looks ok and certainly handles ok (as ride-drive showed me!).

Ian.

[STE VR]

I wish I could put 245's on the back but i'm restricted with the 7J width, i think the standard wheels are a 7.5J.. too late now anyway they are already ordered so i'll let you know how it goes for future info(hope my laptop can get a connection from a ditch)

[nicktowe]

[/quote]
Only a 215 section on a V8 sports car???


[/quote]

Sweeping statement. All depends on the weight of the car, the distribution of the weight, the tyre compounds etc.

My G33 runs 215's and most G33's run 205's (including the 325bhp cars) but they still outgrip an elise and a chim for that matter.

[300bhp/ton]

nicktowe said:

Only a 215 section on a V8 sports car???

Sweeping statement. All depends on the weight of the car, the distribution of the weight, the tyre compounds etc.

My G33 runs 215's and most G33's run 205's (including the 325bhp cars) but they still outgrip an elise and a chim for that matter.

I think you're being difficult. This is a Chim, so the claim was made with the chim in mind. Being that 215 is smaller than stock. It's also the torque not the HP that's the reason you want wider.

BTW - I run a 225 on a 3.5 Rover V8 in a car of similar weight to the Chim, so I thought I'd offer some help.

[ACT]

I can't get hold of Jordan Rs at present due to lack of production in correct offset , when we did sell them 17x7 fronts with 215 40 tyres, rear were 18x7.5" with 235 40 which is as wide as you should go with a 7.5" rim , 7" on the back will mean you'll be limited to narrower tyres.

[akkabit]

Ok guys would be gratfull for some help this tyre thing is frying my brains.
I have just bought some 108 x 18 x 7.5 j Wheels with 40 offset for my 5ltr chim what size tyres do i need --currently have a standard set of estorils with 245-40 - 16 on the back and 225-45 -15 on the front

[spend]

225x35 & 245/255x35 would be the norm for 18" rims.

[akkabit]

thks spend will i assume i will need spacers on the front , looking at this thread would i be right in thinking 15 ml would work?