Metric to 18", but did I get the right size wheels? | FerrariChat
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Metric to 18", but did I get the right size wheels?

Discussion in 'Boxers/TR/M' started by SOFTWAREGUY, Oct 17, 2007.

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  1. SOFTWAREGUY

    SOFTWAREGUY Karting

    Oct 20, 2004
    153
    #1 SOFTWAREGUY, Oct 17, 2007
    I ordered new 18" wheels from SL in July for my 1985 Eurospec Testarossa to replace my old Metric TRX rims.
    While I expected them to arrive with tires on, I just got wheels. But, no problem, Tire Rack has them is stock.
    I placed an order with Tire Rack who had them in stock and can get me them by Friday.

    An hour later I got a call from Tire Rack asking me to double check the size, they seemed too big. I double checked the specs that SL sent, and I ordered what they told me to.

    Nevertheless, I am concerned. The old size width was 210 in the front and 240 in the back. They said to get 235/40/18 in front and 295/35/18 in the back.

    Since the wheels are based on the F50 wheel I am wondering whether they got confused when they gave me the sizes.

    Has anyone upgraded their wheels and if so to what size. Does anyone know if this will rub?
    I called SL, but of course they are closed now.

    Thanks in advance for all input.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,663
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Oct 17, 2007
    I think that you are confusing wheel widths and tire widths. The "old"/stock metric wheel widths are 210mm front and 240mm rear, but the stock metric tire widths are 240mm front and 280mm rear -- so a 235mm wide tire is no problem up front, and the 295mm rear isn't that much wider than the stock rear tire (I wish that I could get a 295mm wide tire for a 16" wheel -- 255mm is just too puny!).

    What are the widths of your new 18" wheels?
     
  3. SOFTWAREGUY

    SOFTWAREGUY Karting

    Oct 20, 2004
    153
    #3 SOFTWAREGUY, Oct 17, 2007
    I am now confused. But you may have answered my questions and calmed me down.

    The sizes I was told to buy for the tires are as above - 235/40/18 in front and 295/35/18 in the back.
    I don't know what the widths are on the wheels. Nor do I know how to find out. Aside from taking out a ruler.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,663
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Oct 17, 2007
    That works ;)

    I can't imagine a F50 wheel being narrower, but measure the inside bead to bead distances on your old and new wheels -- if the new rear wheel is significantly narrower than the old rear wheel that might warrant further worry/investigation, but if it's the same, or a little wider, seems like the 295mm tire would be no problem.
     
  5. Tifosi66

    Tifosi66 Formula 3

    Nov 30, 2004
    1,786
    Jiang Jia Jie
    Full Name:
    Li-Ge
    #5 Tifosi66, Oct 17, 2007
    235/40FF and 295/35RR are stock sizes for the 512TR on the stock 18". That should be ok. BUT, do check yer offset because a few (10) mm here and there is not so much that can cause the the 'rubbing' issue(s) but most critical is the offset of said new wheels. Width wise, fronts should be 8" and rears at 10.5" or slightly more...
     
  6. Hawaii

    Hawaii Formula Junior

    Jan 28, 2007
    847
    Maui
    Full Name:
    Emery
    #6 Hawaii, Oct 18, 2007
    Last edited by a moderator: Sep 7, 2017
    I'm running 235/35/19 front on a 8" wheel and 275/30/19 rears on a 10" wheel. The front rubs just a bit when full lock and hitting a bump like coming onto a drive way too fast but fine other that that. The rears probably could go wider.
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  7. johng

    johng Formula 3

    Oct 23, 2004
    2,298
    northern va
    Full Name:
    john g
    #7 johng, Oct 18, 2007
    i have 295/18 on the back of my testarossa. you should be fine too.
     
  8. SOFTWAREGUY

    SOFTWAREGUY Karting

    Oct 20, 2004
    153
    #8 SOFTWAREGUY, Oct 18, 2007
    Well, I got the tires today - boy those 295's look big.
    So the new tire is 15 bigger.
    But we will see. The rims and tires are out for mounting. Hopefully tomorrow I can get the car over there and put my angst at ease.
    Thanks for all the feedback. Johng, thanks for the comment.
     
  9. RoccoM

    RoccoM Formula Junior

    Oct 6, 2007
    421
    Richmond Hill, ONT
    Full Name:
    Rocco M
    #9 RoccoM, Oct 18, 2007
    I was wondering how much those wheels cost and did you have to change over the hubs to the new rims?. They look amazing. How do I get in contact with SL.
     
  10. SONNY

    SONNY Rookie

    Nov 13, 2003
    18
    #10 SONNY, Oct 26, 2007
    How did you eliminate the knock-off? Is there a conversion kit available for the changeover?
     

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