News

Ferrari 275 GT tyres

Discussion in 'Vintage (thru 365 GTC4)' started by Longstone Tyres, Aug 20, 2013.

  1. Longstone Tyres

    Longstone Tyres Formula 3
    Sponsor

    Feb 2, 2006
    1,360
    Full Name:
    Dougal
    We have recently come accross a situation with Ferrari 275 GTB where some cars were unable to fit the 205VR14 Michelin XWX which of course seemed strange as this is pretty much accepted to be the tyre for that car. When you see a 275 fitting the 205/70VR14 Michelin XWX you can see the difference because the wheel arches seem quite empty. the difference in diameter is 42mm (1 5/8 inches).

    I now think that the early cars were fitted with a 185R14 tyre. does anybody know for definate what these early cars fitted. i would also be interested to know what make of tyre they fitted.
     
  2. To remove this ad click here.

  3. Ferrari_250tdf

    Ferrari_250tdf Formula Junior

    Mar 3, 2005
    379
    According to the factory documents the 275 GTB have been fitted with either Dunlop 205 HR x 14 SP or Pirelli 210 x 14 HS.
     
  4. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    I was quite surprised to see the HR rated tyres recommended and used for a 275 GTB as they are only rated for speeds up to 130 mph but perhaps that was the highest rating in 1964? The VR rating was 130 MPH +.
     
  5. per904

    per904 Karting

    Feb 28, 2009
    79
    switzerland
    For info 275GTB/4 09355 was delivered with Dunlop tyres 205x14 HR according the "foglio montaggio autotelaio" dated 21/12/66.

    rgds
     
  6. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    Perhaps the HR rating was different in 1964 and not just up to 130 MPH but had a higher speed rating? Could it have been that the tyre industry changed/regraded the ratings when they brought the VR 130 mph + rating out?
     
  7. To remove this ad click here.

  8. per904

    per904 Karting

    Feb 28, 2009
    79
    switzerland
    or, may be,the VR rating doesn't exist in 1966!...
     
  9. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    That is what I suspect. As I said above, perhaps the HR rating was the highest and the recommendation for very high performance cars until the introduction of the VR rating? Does anyone know when the VR rating was introduced?
     
  10. lancia

    lancia Formula Junior

    Jan 18, 2004
    370
    Early brochures show both 195-14 and 205-14, though I do not know if the 195 was used in application; Dunlop SP Sport 205-14 or Pirelli 210-14 seem to be the norm on data sheets. 185-14 is simply too small for a 275, no references to this size used to my knowledge.
     
  11. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    #9 miurasv, Aug 20, 2013
    Last edited by a moderator: Aug 21, 2013
    The Ferrari web site states tyre sizes for the 275 GTB of 195 x 14 or 205 x 14. No speed ratings given.

    See here: http://www.ferrari.com/english/gt_sport%20cars/classiche/all_models/Pages/275_GTB.aspx

    For 275 GTB/4 the Ferrari web site states 205 x 14. No speed rating given. See here: http://www.ferrari.com/english/gt_sport%20cars/classiche/all_models/Pages/275_GTB4.aspx

    Ian Webb's book Ferrari 275GTB & 275 GTS states Pirelli or Dunlop 195 x 14; then 205 x 14 often Michelin.

    The 195 x 14 size was probably just found on the Starburst alloy wheels which were of 14" x 6.5" size. The later slotted alloy wheels introduced on the Long Nose cars were of 14" x 7" size.
     
  12. To remove this ad click here.

  13. DWR46

    DWR46 Formula 3
    Honorary

    Jun 19, 2012
    1,380
    275 GTB's and GTS's were mounted from the factory with Dunlop 195x14 tires up to about chassis 6900. From there to about chassis 7200, the factory mounted both Dunlop 194x14 and Pirelli 205x14 tires in no particular order on both GTB's and GTS's. After chassis 7400, Pirelli 205x14 and Pirelli 210x14 tires were mounted. The last high 8000 range cars were built with 205x14 Dunlops.
     
    miurasv likes this.
  14. Longstone Tyres

    Longstone Tyres Formula 3
    Sponsor

    Feb 2, 2006
    1,360
    Full Name:
    Dougal
    #11 Longstone Tyres, Aug 21, 2013
    Last edited by a moderator: Sep 7, 2017
    I would suggest that a 275 these days fits the 205VR14 Michelin XWX. nobody makes a 195R14 or 210R14 that i am aware of. the Michelin XWX tyre in this size are only made with a V rating in the description because thats what they were called in the day and V speed rating in those days meant 149>mph. This tyre is now actually W rated which is 170mph.

    Michelin are the only manufacturers to make a 205Vr14 (full profile) tyre.they only fit a few Ferrari, a few Maserati and a MK10 Jaguar.

    here's what you get if you fit 205/70VR14 tyres
    Image Unavailable, Please Login
     
  15. SteviePPS

    SteviePPS Karting

    May 11, 2013
    66
    EU
    Full Name:
    Steve Warson
  16. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    The 89W lettering relates to the load rating not the aspect ratio. Michelin XWX 205R 14 89W will be full 80% (or 82%) aspect ratio and are not taller.
     
  17. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    #14 miurasv, Aug 21, 2013
    Last edited: Aug 21, 2013
    The V speed rating up until 1991, when the ratings changed, was recommended for speeds of 130 MPH +.

    H up to 130 MPH.

    S up to 112 MPH.

    http://en.wikipedia.org/wiki/Tire_code#Speed_rating
     
  18. BIRA

    BIRA Formula Junior

    Jun 15, 2007
    895
    Who drives his GTB above 150mph?
    Specially with original Cromodoras in magnesium that can desintegrate in one second?
     
  19. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    It's not just for high speed that the tyres on a 275 GTB and similar cars need to be V rated, but also to cope with the higher forces of acceleration, cornering and braking that the car generates. :)
     
  20. SteviePPS

    SteviePPS Karting

    May 11, 2013
    66
    EU
    Full Name:
    Steve Warson
    I'm quite aware of what the 89W stands for, thanks. And yes, the 205R14 shown is those pictures is quite a bit taller then the 205/70R14 shown in the picture Dougal (Longstone tyres) posted.
     
  21. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    Sorry, I misinterpreted your post. Nice alloy 4 cam in the link you posted.
     
  22. 275GTBSaran

    275GTBSaran Formula Junior

    Mar 5, 2012
    966
    Zurich, Switzerland
    Full Name:
    Le Monde Edmond
    I wonder when Sheehan had that 275 GTB/4 allloy for sale.
    To think that today you put a 1 before that price and it probably
    still would not be enough for this car. My guess is around 2002, 2003, or 2004.
     
  23. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,797
    London
    Full Name:
    Mark
    #20 275GTB, Aug 30, 2013
    Last edited by a moderator: Sep 7, 2017
    well for me the tire debate is over - the Michelin 205 x 14 full profile (80) tire fits perfectly on my car, they fill the wheel arch and look fantastic!

    Note - the 205 x 14 does not fit in the spare wheel space of the shortnose car, you need a small 190 or 195 x 14.

    Supplied by Longstone - THANKS
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  24. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    Would deflating the spare XWX 205 x 14 tyre, making it slightly narrower for the spare wheel space, and carrying a foot pump or a small compressor powered from the cigar lighter be a solution?
     
  25. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,797
    London
    Full Name:
    Mark
    it may work, but happy with a smaller tire fully inflated. Imagine it as a vintage space saver!
     
  26. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
    8,038
    Cardiff, UK
    Full Name:
    Steven Robertson
    Is the XWX available in 195 x 14 (80) size or are you using a different tyre?
     
  27. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,797
    London
    Full Name:
    Mark
    dont know - Longstone?

    I have not fitted the smaller tire yet, but not that bothered about matching, make etc - given it is only to get me home in the event of a puncture.
     
  28. Longstone Tyres

    Longstone Tyres Formula 3
    Sponsor

    Feb 2, 2006
    1,360
    Full Name:
    Dougal
    I have had a reply from Michelin incidentally:-

    "You are right when you say than early 275 GTB was fitted with 195 VR 14 on his early days ( 1964 ), then moved to 205 in 1966, if my informations are correct..."

    They say that the 205VR14 Michelin XWX is made in the same mold as before "so diameter is the same. They are wider when unfitted, but after their mounting, they shoud be as wide as before."

    The laws that determine what we are allowed to use when manufacturing tyres change so there is a slight possibility that that might effect the dimentions. Next time we fit a set of 205VR14 Michelin XWX i will measure the width. However this will generally be on Ferrari 275 GTB Borrani Wheels RW 4039 which is also 7" rim so it should give correct measurements.
     

Share This Page