Help clarify tire and rim sizes | FerrariChat

Help clarify tire and rim sizes

Discussion in 'Boxers/TR/M' started by Surge74, Jul 13, 2017.

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  1. Surge74

    Surge74 Rookie

    Jul 6, 2017
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    Surge
    Hi,

    I've tried to figure this out, but it's confusing. The early TRs (~1987 and earlier) came with Michelin TRX tires on 15" single bolt wheels, correct? And it's hard/impossible to now source the rear tires...
    When I see cars with what appear to be OEM single bolt wheels wearing BFG tires, aren't those 16" and non-OEM tire sizes? So did they also make factory 16" single bolt wheels?
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    30°30'40" N 97°35'41" W (Texas)
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    Never heard of that before, and the TR OMs say otherwise IIRC.

    Yes, 16" and 415mm (although it's still very hard to get the 16" rear tires today ;)).
     
  3. Natkingcolebasket69

    Natkingcolebasket69 F1 World Champ



    I thought even thev85-87 had 16wheels tyres. Only thing different was the rim itself.



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  4. ago car nut

    ago car nut F1 Veteran
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    Where not the early cars metric size?
     
  5. TRCo

    TRCo Karting
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  6. Surge74

    Surge74 Rookie

    Jul 6, 2017
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    Surge
    Thanks, so from Red Headed:
    The first Testarossas had single-bolt wheels. There were in fact three types of single-bolt wheels, although they all looked the same. One type (210 TR 415 / 240 TR 415) was for the TRX tires and two types (both 8J x 16 / 10J x 16) were for "regular" tires, very probably made by two different manufacturers.

    The TRX tire was a 15" rim, correct?
    So if you buy one of these with the original rims, you will need to switch to 16" to have a hope of finding the right tire sizes, correct?
     
  7. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

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    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #7 Steve Magnusson, Jul 13, 2017
    Last edited: Jul 13, 2017
    No, the "210 TR 415 / 240 TR 415" are 415mm diameter rims (not 15" diameter).

    I believe that is correct as even the one euro supplier (Longstone Tyres) who could get the 415mm rears indicated they are out of production (although the TRX sizes they list do not quite match your numbers - http://www.longstonetyres.co.uk/page/ferrari-testarossa). But even the 16" rears are getting to be trouble -- either very expensive Michelins or soft Toyo racing tires are about the only options -- see this thread:

    http://www.ferrarichat.com/forum/boxers-tr-m/552953-tire-source-bfg-comp-2-dried-up.html
     
  8. Surge74

    Surge74 Rookie

    Jul 6, 2017
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    Surge
    I see, because BFG is no longer producing rears in 16".
    Thanks, very helpful.
     

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