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Trek Round Ultra-light Carbon Seat Mast Cap & 10mm Ears


Availability: Contact to Confirm



Genuine replacement parts

Originally developed for the incredibly light Émonda SLR 10, the SLR seat mast cap is the lightest available for Trek bikes equipped with round seat masts.

This high-end cap comes with 7x10mm oval ears, so it's ready for most carbon-railed saddles out of the box but able to convert to 7mm round or 7x9mm ears instead if necessary.

Product details

  1. Lighter than the standard round carbon seat mast cap
  2. Direct fit on all Trek road bikes with round seat masts
  3. One bolt head design offers easy fore-aft and infinite angle adjustment
  4. Includes 10 mm oval saddle clamp ears, 7 mm round ears sold separately


Size 135mm x 5mm 135mm x 20mm 175mm x 5mm 175mm x 20mm
Length 135 mm 135 mm 175 mm 175 mm
Offset 5mm 20mm 5mm 20mm
Rail compatibility Universal Universal Universal Universal
Material Carbon Carbon Carbon Carbon
Weight 117g 117g 134g 134g