A class conversions - chassis track/wheel arches - spacers

Discussion in 'Mercedes' started by Hagstrom, Dec 27, 2015.

  1. Hagstrom

    Hagstrom Funster

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    Hi,

    Most A Class conversions have bodywork over-reaching the chassis track, resulting in heavy rolling going around corners and wheels 'lost' within wheel arches. I expect this has been considered by the converters (- indeed FIAT has increased the track of more recent MH conversions.)

    There are now hub-centric spacers (see the TUV approved Sprinter spacers at http://www.wheelspacers.uk.com which could increase track by 4inches per axle) and enhance the handling and appearance of Sprinter based A Class conversions. These hub-centric spacers maintain the load on the hub rather than "thick washer spacers" which transfer it to the wheel studs.

    I've emailed Mercedes about the feasibility of fitting such spacers and have expected responses which might include references to hub loads in excess of design parameters but have had no reply.

    Has anyone else made better headway with chassis manufacturers on fitting hub centric spacers?
     
  2. hilldweller

    hilldweller Funster Life Member

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    That sounds nonsense to me.

    If you move the wheel out by 4 inches instead of the tyre load going from contact patch in line to the bearings you are creating a considerable torque on the bearings which probably are not designed for this.


    BRG...........................SPCBRG
    LOD...........................LOD
    ...................................twist

    ( Got to use dots to get round forum editor )

    And your tyre may hit the skirt.
     
  3. pappajohn

    pappajohn Funster Life Member

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    I agree with Brian above.

    Moving the load outwards by 2" per wheel can only place excessive loads on the bearings which are now off centre to the wheel rim.
    May be ok on a far lighter car but not a 3500kg motorhome.
     
  4. jockaneezer

    jockaneezer Funster

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    Save your money and just put your wheels on back to front :xgrin:
    Having said that, I always thought those old model Mercedes Hymers look as if they'd blow over in a stiff breeze, they remind me of an obese Commer van.
     
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  5. dave newell lvs

    dave newell lvs Trader-Vehicle Services

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    As the guys above have said its really not a good idea. The front/rear centre line of each wheel should coincide with the centreline of the wheel bearings, this way the inner and outer races of the bearing carry equal load. Spacing the wheels outboard of this moves the load centre and will cause more load to be carried by the outer race, almost certainly leading to premature bearing failure. Its also unlikely to have any real positive effect on handling as the biggest problem is body roll which is a product of cornering forces, roll centres and spring rates. The body rolls on the springs relative to the axle, a wider axle doesn't alter the body roll characteristics.

    D.
     
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  6. Peter A Forbes

    Peter A Forbes Funster

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    Mercedes have various options available on their chassis, one in particular may be of interest.

    Our build sheet for the 614D shows that it was fitted with 'Soft Suspension', heavy duty anti-roll bar etc.

    It was sold for conversion to a bus, so whether it was intended for comfort of just that the bus probably wouldn't reach its design weight I don't know, but it certainly makes a difference to the way the vehicle handles.

    It also had underseal from new.

    Peter
     
  7. makems

    makems Funster Life Member

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    We used to have a Sprinter based A Class Rapido and the body roll was horrendous. We fixed it by fitting air suspension (air bags) to the rear. Not too expensive. Lots of threads on here about it including an excellent DIY guide with photos. Was it @Techno100 who posted it?
     
  8. funflair

    funflair Funster Life Member

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    So that looks like a NO then, the narrow track on the Merc and IVECO lightweight 5t chassis is one thing that puts me off these options.

    Martin
     

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