Bus Bellows

Since the early 70’s, Dynatect has supplied OEM and replacement units to numerous transit authorities and bus manufactures throughout North America. Dynatect manufactures drop-in replacements for Dynatect and other OEM bus bellows. This includes entire assemblies or components including the bellows, mounting clips, hip boots, floor, and false ceiling.


  • Dynatect manufactures drop-in replacements for Dynatect and other OEM bus bellows (lower cost alternative with same design)
  • Dynatect can provide complete bus bellows or separate components for replacements driven by:
    • Collisions impacting only one side of a bus
    • Floor deterioration due to weather or salt
    • Vandalism like cuts or graffiti on the bellows
  • Existing bus bellows designs include:  Standard, Extended / Full Roof Cap (cover roof-mounted accessories on the bus and provides continuity with upper bus fairing for aesthetics), & BRT (New Flyer Bus with special shape)
  • Dynatect will no-cost reverse engineer and provide prototype of any existing design if not already in our portfolio.  Coordinate in advance providing an existing unit for evaluation.
  • Easy Mounting – simple features and connection points between components that minimize replacement time
  • Materials are selected to conform with these challenging environmental conditions and regulatory requirements:
    • Harsh weather
    • Withstand continuous flexing
    • Light debris
    • Fire retardant requirements
    • UV exposure

Basic Components

The components of bus bellows include:

  • Main Bellows / Folding Bellows:
    • Inside valley of each convolution is stitched and then has an aluminum-extrusion crimped-on to provide support for the false-ceilings and hip boots
    • Outside peaks of convolutions are captured with a crimped aluminum-extrusion
    • Dynatect bellows incorporate easy-to-use mounting clips that don’t require tools for installation; competitors clips must be manually screwed-in to the ceiling or hip boots.
  • Hip Boots / Floor Cover/ Floor Skirt:
    • Dynatect provides new and replacement hip boots
    • Dynatect provides replacement / retrofit hip boots for legacy designs with drop-in extrusions and clip technology
    • Front and rear units are required for both street and curb sides
  • Floor Assembly:
    • Dynatect makes one-piece and two-piece drop-in floors
      • Selecting the two piece design allows replacement of only half a floor if only damaged on one side.
    • Dynatect’s floor material, rubber, and connecting channels are thicker and more robust than competitors designs.
    • Bellows Mounting Seal:
      • Bulkhead Mount and Center Hoop Mount
  • False Ceilings / Roof Cover:
    • Mounts with in a tongue and groove arrangement using either folding or solid plastic clip
    • Multiple designs shown and available
  • Extensions & Roof Caps
    • Cover CNG tanks, batteries, power cables, etc

Looking for a other bellows? We have experience supplying custom bellows for similar applications in transportation, such as:

  • Bellows for ventilation of traction motors (on electric locomotives/railcars)
  • Bellows for air ducting
  • Cylinder rod covers
  • Steering column bellows
  • Bellows covers for door hinges
  • Shift/joystick bellows