17" - wheels, sizes, tires

17" - wheels, sizes, tires

Author
Discussion

GermanCerb

Original Poster:

39 posts

35 months

Monday 7th June
quotequote all
aka_kerrly said:
clap very good looking TVR !!!!!!!!!!

Fantastic choice of wheel, significantly better than your original ideas & looks like you got the sizing pretty dam spot on to.
Thanks! smile It took me so long to decide and I was really afraid that they might not fit but now I'm really happy! biggrin

Byker28i

35,858 posts

185 months

Tuesday 8th June
quotequote all
GermanCerb said:
Byker28i said:
Why 45 profile front and 40 profile rear, are these the sizes that were available or through choice?
That came from the discussion above. 235/40 is difficult to find - there are just a few choices. 225/45 is standard size for lots of cars so also lots of choices.
The rolling circumference is still a bit lower on the front compared to the rear (original 235/40 & 255/40 is 188,4cm vs. 193,3cm and now it's 192,8cm vs. 193,3cm).
Love the choice of wheels, they really suit the car.
I have the original RL7's with I think 235/40 front and 255/40 rear, as you say 235/40 is hard to find...
Still only did 900 miles in mine last year...

DuncanM

4,357 posts

247 months

Thursday 10th June
quotequote all
If you're a 4.2 owner, the original sizes were 235/50/16 and 225/45/16

I have RL7s now, and have decided to go for 245/45/27 and 225/45/17

The rears are nice and close to original diameter, the front to rear ratio changes slightly, in favour of the fronts (a good thing imo).

I'm happy with this, and both sizes have good availability of choice and stock.





FarmyardPants

3,707 posts

186 months

Thursday 10th June
quotequote all
Going a bit smaller in rolling radius gives you a free brake upgrade smile

DuncanM

4,357 posts

247 months

Thursday 10th June
quotequote all
FarmyardPants said:
Going a bit smaller in rolling radius gives you a free brake upgrade smile
Yes indeed, and reducing the front/rear ratio, moves the bias in the favour of the fronts also, which is a good thing on a Cerbera (certainly mine anyway) smile



Edited by DuncanM on Thursday 10th June 16:56

Byker28i

35,858 posts

185 months

Friday 11th June
quotequote all
DuncanM said:
If you're a 4.2 owner, the original sizes were 235/50/16 and 225/45/16
Didn't the later cars come with 17" RL7's?

DuncanM

4,357 posts

247 months

Friday 11th June
quotequote all
Byker28i said:
Didn't the later cars come with 17" RL7's?
I believe the RL7s were the original 4.5 wheels, but don't know for sure. Mine came with 16s, I changed to RL7s when tyre choices became too scarce in 16".

The tyre sizes are from my handbook (235/50 225/45 16).

Edited to correct sizes in handbook:

Rear 235/50/16
Front 225/45/16

Edited by DuncanM on Friday 11th June 11:48

ukkid35

5,570 posts

141 months

Saturday 19th June
quotequote all
My 928 also came with 16" wheels, and they needed 225/50-16 F 245/45-16 R

The rears were an absolute PITA to find, especially when abroad in emergencies (Spa and Florence)

Now I'm using 17" wheels on my 928, which means I can use exactly the same size tyres on both cars

235/40-17 F 255/40-17 R

Makes life so much easier now that both are on the awesome AD08R

The only fly in the ointment is that they are now NLA and the new AD08RS are reputed to be far less impressive

DCerebrate

281 posts

78 months

Sunday 20th June
quotequote all
For those running 235/40 17’s at the front, what do we think of Toyo Proxes Sports, now listing on MyTyres?

gruffalo

6,664 posts

194 months

Sunday 20th June
quotequote all
DCerebrate said:
For those running 235/40 17’s at the front, what do we think of Toyo Proxes Sports, now listing on MyTyres?
Very average tyre, I use Michelin Pilot 4 in 255/40/17 all round as a road tyre and Cup 2 or R888R for track or summer months.

Putting 255 on the front gives slightly more tram lining but otherwise no issues for me and the Michelins offer immense grip and durability.

DuncanM

4,357 posts

247 months

Sunday 20th June
quotequote all
gruffalo said:
Very average tyre, I use Michelin Pilot 4 in 255/40/17 all round as a road tyre and Cup 2 or R888R for track or summer months.

Putting 255 on the front gives slightly more tram lining but otherwise no issues for me and the Michelins offer immense grip and durability.
A square setup sounds interesting, no issues with running then?

gruffalo

6,664 posts

194 months

Sunday 20th June
quotequote all
DuncanM said:
gruffalo said:
Very average tyre, I use Michelin Pilot 4 in 255/40/17 all round as a road tyre and Cup 2 or R888R for track or summer months.

Putting 255 on the front gives slightly more tram lining but otherwise no issues for me and the Michelins offer immense grip and durability.
A square setup sounds interesting, no issues with running then?
Nope, some tyres rub on the inner wing on full lock but not the Michelins or Kumho V70 as they seem to have a slightly smaller diameter than the Bridgestones I tried which did rub but harmlessly, just rubbed some of the paint off the inner wing.
The biggest noticeable thing is slightly more tram lining but I do run 3deg of negative camber to get the front into tight corners on track days without the under steer the Cerb is prone to in standard set up.

DuncanM

4,357 posts

247 months

Sunday 20th June
quotequote all
Nice, and good to hear about alternative setups working on these cars smile.

I hope to have more to say on the matter soon, I've fitted new suspension and tyres, but need to sort the temp gauge (bloody thing!) before doing a real test drive.



gruffalo

6,664 posts

194 months

Sunday 20th June
quotequote all
DuncanM said:
Nice, and good to hear about alternative setups working on these cars smile.

I hope to have more to say on the matter soon, I've fitted new suspension and tyres, but need to sort the temp gauge (bloody thing!) before doing a real test drive.
Drop me a call if you want a real chat 07920 494667.

Jhonno

4,040 posts

109 months

Monday 21st June
quotequote all
DCerebrate said:
For those running 235/40 17’s at the front, what do we think of Toyo Proxes Sports, now listing on MyTyres?
Average at best. I'd rather run 225/45 in PS4 flavour.

GermanCerb

Original Poster:

39 posts

35 months

Tuesday 20th July
quotequote all
Hi all,

just to add a comment: I'm really happy with my choice of tires! biggrin
The PS4 are great in the dry as well as in the rain. Been a week in the Alps and had some heavy rain one day. Traction was very good, even on the curvy roads. Of course you'll have some aquaplaning due to the size of the tires and the weight of the car - this cannot be avoided. But I hadn't one turning which I easily had with my old Hankooks in the wet. wink

Cheers
Michael

FarmyardPants

3,707 posts

186 months

Thursday 22nd July
quotequote all
Glad you’re enjoying your new wheels and tyres, they really suit the car.

I have finally got mine fitted and am also very pleased. A couple of rubbish photos:





I also went for PS4’s on the front.

What I’m most pleased about is the way it drives and the weight saving: my 9.5J 18 rears are 5Kg lighter than the ET33 8.5J spiders, for example. I haven’t yet weighed the spider ET42 but expect to save more than 20Kg of wheel weight and it really shows. I’ll add to a wheel weight thread with my findings smile

Edited by FarmyardPants on Thursday 22 July 19:29

GermanCerb

Original Poster:

39 posts

35 months

Thursday 22nd July
quotequote all
Nice! They fit also perfectly to your car! cool
Why not PS4 on the rear too? Not available?

Cheers
Michael

FarmyardPants

3,707 posts

186 months

Friday 23rd July
quotequote all
No it’s just that I reused the 255 tyres I had on the spiders as they were almost new.

Jhonno

4,040 posts

109 months

Friday 23rd July
quotequote all
FarmyardPants said:
Glad you’re enjoying your new wheels and tyres, they really suit the car.

I have finally got mine fitted and am also very pleased. A couple of rubbish photos:





I also went for PS4’s on the front.

What I’m most pleased about is the way it drives and the weight saving: my 9.5J 18 rears are 5Kg lighter than the ET33 8.5J spiders, for example. I haven’t yet weighed the spider ET42 but expect to save more than 20Kg of wheel weight and it really shows. I’ll add to a wheel weight thread with my findings smile

Edited by FarmyardPants on Thursday 22 July 19:29
Love those wheels! What are they?