Carbon Fiber Chassis Sets Up Promising Future for BMW - 2014 BMW i3 Long-Term Road Test

Comments

• grijon Member Posts: 147

  May 2015

  Very cool. Thanks, Jason.

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• mercedesfan Member Posts: 365

  May 2015

  I am going to be really interested to see if BMW's carbon fiber mainline vehicles really are significantly lighter when they hit the streets. The elephant in the room that no one talks about is refinement. Carbon fiber is a terrible suppressor of sound and vibration. Unlike steel, carbon fiber transmits ever ripple and every sound wave directly into the cabin. As a result, auto manufacturers have to stuff the vehicles full of extra sound deadening material to compensate, and the sound deadening material is heavy. The i3 skirts a lot of these challenges by using ridiculously skinny tires, but a 5er or 7er is going to need wide, and therefore loud, rubber. Then again, BMW's have always had a reputation for being comparatively noisy inside so it may not matter as much for them. Companies like Lexus, MB, RR, and Bentley are going to have a monumental challenge, though.

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• fordson1 Unconfirmed Posts: 1,512

  May 2015

  I think most hybrid vehicles that are heavier than this have ICE powerplants that are powerful enough (and heavy enough...) to directly propel the vehicle at acceptable speeds, which really can't be said about the range-extender model, which weighs only 265 lbs. more than the non-RE model.
  
  One the other hand, because they have larger, more powerful ICEs, most hybrids don't have the potential the i3 does to turn into rolling roadblocks under some circumstances. So I don't think it's a fair comparison.

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• duck87 Member Posts: 649

  May 2015

  The challenge in using CF goes beyond simply getting it into production. It's not an issue yet because there aren't that many cars on the road with them, but at the end of their vehicle lives CF is not recyclable, whereas almost all of the steel and aluminum is recovered (>98%). That's getting beyond the fact that production of the fibers is energy intensive- something that BMW has sought to minimize with their enviro-friendly manufacturing plant.

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• desmolicious Member Posts: 671

  May 2015

  The sound deadening material may be replaced by noise cancelling signals from the stereo. They already are pumping fake engine noises through the speakers on some of their cars.

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• anotherdrunk Guest Posts: 30

  May 2015

  nice read jason
  
  dorky-looking? wtf?
  
  that's why i bought the damn thing is because it's so cool looking!

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• shadrach2 Member Posts: 9

  May 2015

  Desmolicious, as someone who's worked on active sound cancellation in automobiles, I can say, in my opinion, that it's not going to be the answer. Pumping in sound is trivially easy. But canceling the sound coming from essentially everywhere (from the roof, the side panels, the floor) is impossible Some engine harmonics can be quelled, sure. But unless the occupants are wearing headsets it's not going to happen. There's no way to get the car's speakers, regardless of how many are used, to handle the acoustic load.

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• stillageek Member Posts: 114

  May 2015

  duck87 said:

  The challenge in using CF goes beyond simply getting it into production. It's not an issue yet because there aren't that many cars on the road with them, but at the end of their vehicle lives CF is not recyclable, whereas almost all of the steel and aluminum is recovered (>98%). That's getting beyond the fact that production of the fibers is energy intensive- something that BMW has sought to minimize with their enviro-friendly manufacturing plant.

  Actually the I3 is very recyclable...including the CF...
  
  https://www.youtube.com/watch?v=KdP1OlzvJg4

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