World Library  
Flag as Inappropriate
Email this Article

Dustcap

Article Id: WHEBN0000812042
Reproduction Date:

Title: Dustcap  
Author: World Heritage Encyclopedia
Language: English
Subject: Valves, Cable guide, Skirt guard, Tires, Bicycle basket
Collection: Automotive Accessories, Bicycle Parts, Tires, Valves
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Dustcap

A dustcap is a small cover used on the valve stem of a bicycle or car tire to prevent dust or other small particles from entering the valve and damaging it. The dustcap also forms a pressure seal, helping to prevent deflation of the tire due to slight gas seepage past the tire valve. Dustcaps are usually made from plastic but may occasionally be made of metal. The dustcap is internally threaded and is secured by screwing it onto the end of the stem. To prevent corrosion due to electrolysis and malfunction of the electronics in a direct TPMS and avoid costly repairs, metal valve caps without insulating plastic linings should not be used on direct-TPMS-equipped tire valve stems.

A dustcap may also refer, on a bicycle, to the crankarm bolt cover. It is usually a piece of metal or plastic that, on the crankarm, is snapped or screwed into the threaded counterbore, which houses the bolt that holds the crankarm to its axle, the bottom bracket spindle. The dustcap serves to protect the threads (on the inside of the counterbore), which are used with a crankarm puller to remove the crankarm from the spindle. It is also possible for the crank arm to squirm on the bottom bracket spindle, causing the crankarm nut/bolt to become loose, leading to the nut/bolt working its way out of the bottom bracket spindle. The dust cap limits the amount of dangerous loosening that can occur.

A dustcap may also refer, on a bicycle, to the metal ring that covers the bearings in a cup-and-cone ball-bearing hubset. These types of dust caps, being press-fit, are difficult to remove with bending or damaging them. It is suggested to press them out from the other side of the hub using a screw driver. In this role the dustcap reduces the dust that enters the bearing races, and extends service intervals.

See also

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.