B4036: 1-1/2" Round, Flat and Low Mount Dropouts, No Hanger, Shimano 12 mm

B4036: 1-1/2" Round, Flat and Low Mount Dropouts, No Hanger, Shimano 12 mm
Skewers are available at a 23% discount with the purchase of this insert (see Related Products below)

12 In stock

  • Buy 10 for $13.98 each and save 8%
  • Buy 25 for $12.82 each and save 16%
  • Buy 50 for $11.67 each and save 23%


This is a right side insert for our rear 1-1/2", low mount, and flat mount dropouts. It is compatible with the skewers shown in Related Products below. Made from black anodized 6061 aluminum, it has no derailleur hanger for single speed applications.

Included are two M4 mounting screws and a 14 mm long retainer and M4 x 8 mm button head cap screw that hold the Shimano nut captive. Install the wheel and skewer with the flanged (larger) portion of the nut in the recess of the dropout. There are nine notches in the retainer that index the notches on the nut. This allows the closed position of the skewer to be adjusted every 40 degrees for optimal location. If none of these positions work, the retainer can be flipped over to utilize nine more positions that are 20 degrees out of phase from the original positions.

Important Information

  1. Skewers are available at a 23% discount from Related Products below (discount taken in cart) . Limit one skewer discount per insert.
  2. Skewer and insert compatibility is only guaranteed when used with a compatible Paragon Machine Works product.
  3. Sorry, no returns on skewers. Please check skewer drawings for measurements before ordering.
  4. We are not able to advise or make recommendations on compatibility with products that are not manufactured by us.

Item sold as 5 piece set.



Item Number B4036
Weight/Grams 14
Alloy 6061
Skewer OD 12 mm
Plating Black Anodization
STEP File (right click, "save as") B4036
PDF Drawing Insert and Dropout Options