Tyres R129 AMG Monoblock style

Discussion in 'Wheels, Tyres, Brakes & Suspension' started by inazar, Mar 18, 2017.

  1. inazar

    inazar New Member

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    Car:
    R129 300SL 24V
    First post, so please be gentle.

    I've just taken ownership of a 300SL (R129) 1991 Model.

    Needs a few little things to get it back to it's former glory, bit of paint, bit of upholstery and unfortunately the job of sorting out the wheels.

    The car came with a set of AMG Monoblock style split rims. Although they actually looked great, they are replicas. The outer rim was chewed up a bit on 3 of the wheels, so I've had them cut and re-polished and will get the middle section painted up myself.

    The question I have from a more technical view is regarding tyres.

    The old tyres were probably contributing to the ease of kerb damage, so would it be okay to buy a wider tyre?

    Current fitting is 235 40 18 at the front and 265 40 18 at the back. Could I go wider say 245 and 275? I'm not keen on dropping the profile, I think 40 fills the gap with the height of the motor perfectly well.

    Similarly on my daily runner, I have a set of 19 MV4 rims on a BMW (sorry). The standard fitment is 225 35 19 at the front and 255 30 19 at the back. Can I INCREASE the profile, or does that affect the speedo?

    Any technical advice would be appreciated!
     
  2. RichardF

    RichardF Hardcore MB Enthusiast

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  3. BTB 500

    BTB 500 MB Club Veteran

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    What are the rim widths? You can check what the tyre sizes should be here:

    Mercedes-Benz Fitting Chart and Wheel Fitment Guide | Alloy Wheels Direct

    235/40 front 265/40 rear isn't a listed combo.

    The 18" AMGs on mine (8.5" wide front, 10" wide rear) use 245/40 and 275/35.

    The other point is that some tyres nowadays have rim protection ... a ridge that sticks out and will hit kerbs etc. before the wheel does. It's not perfect but it definitely helps prevent minor scrapes. E.g.

    https://www.tyreleader.co.uk/tyres-advices/tyre-with-rim-protection

    I use this type of tyre on my SL.
     
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  4. OP
    OP
    inazar

    inazar New Member

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    R129 300SL 24V
    Cheers for that link.

    As a bit of a noob :fail, I just went by the tyre on the car. But given that the polished edge was so chewed up, I should've figured it would need a wider tyre.

    I imagine even the replicas would be based on the fitment of the originals, so whoever put these old tyres on must've been drunk or found a cheap deal and thought sod it.

    On the quoted sizes in my OP, I was quoted four P Zeros fitted for £400. There goes that dream :(
     
  5. RichardF

    RichardF Hardcore MB Enthusiast

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    Never assume.

    The width will be embossed on the rim, you may have to remove the wheel to find it. My replicars were 7.5J, MB would be 8.25J on 17" rims. Not a problem if the offset is ok and the appropriate tyre size is used.

    Mercedes SL Class Alloys (R129) - Alloy Wheels Direct

    http://www.tyresizecalculator.com/tyre-wheel-calculators/tyre-size-for-rim-size-width-calculator

    Any given wheel width will have a range of suitable tyre sizes. The bigger wheel and tyre combos MB use require the arch's rolling to avoid rubbing. A bad idea IMO, makes them even more of a dirt trap than they already are.
     
    Last edited: Mar 20, 2017
  6. BTB 500

    BTB 500 MB Club Veteran

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    Yup check the actual size and go from there. Often you can find the details on the back of the wheel using a small inspection mirror and a torch.
     
  7. DanMorgan

    DanMorgan Hardcore MB Enthusiast

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    Car:
    R129 300SL 24V, W124 300CE, W210 E55 AMG, W140 S280
    I've ran 275/35/18 - 245/40/18 and 265/35/18 - 235/40/18 profiles and current run the latter.

    Personal preference and cost but im runner slightly thinner tyres as I plan to slightly lower the car in the future
     
  8. demetrios

    demetrios Hardcore MB Enthusiast

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    Was wondering if I could get wider tyres on my SL.
    265/35 r18 rears at the mo on 18" AMG wheels.
     
  9. OP
    OP
    inazar

    inazar New Member

    Messages:
    8
    Joined:
    Mar 5, 2017
    Car:
    R129 300SL 24V
    Went with 245/40/18 and 275/40/18.

    Will have pics once bodywork has had a tidy up on a couple of corners.

    Due to the lathe cut on the outer rim of the wheels, I had to go wider, curb rash scares me and any protection will do.

    Hopefully they fit on just nicely and aren't too thick.
     
  10. RichardF

    RichardF Hardcore MB Enthusiast

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    Ideally you'll want 10J on the back and 9J on the front. 9.5J all round would be okay though.
     
  11. RichardF

    RichardF Hardcore MB Enthusiast

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    Hopefully you'll be ok, but check the cruise control tyres are on.
     

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