Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: AMuzi Newsgroups: rec.bicycles.tech Subject: Re: First flat in a looooong time Date: Tue, 1 Apr 2025 15:37:12 -0500 Organization: Yellow Jersey, Ltd. Lines: 49 Message-ID: References: <9jb9ujhl5v9o2aph80i4muia5r2o6qqhf4@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Tue, 01 Apr 2025 22:37:12 +0200 (CEST) Injection-Info: dont-email.me; posting-host="f595bfb69edaf939bb8243cd776eb764"; logging-data="3987212"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX199vjs9bt8+Udft1QZ0sg5z" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:zI2Izu1zS/1gCJPBzw3rk+WmW5M= Content-Language: en-US In-Reply-To: Bytes: 3080 On 4/1/2025 3:02 PM, Jeff Liebermann wrote: > On Wed, 26 Mar 2025 22:01:05 -0400, Joy Beeson > wrote: > >> Tuesday, 25 March 2025 >> >> On Saturday, I came out of Aldi to find my front tire flat. >> >> On Monday, I walked to the Trailhouse and handed the wheel >> to the mechanic with instructions to put in a new tube and >> find out what had happened to the old one. >> >> He showed me a crack at the base of the valve stem. The >> tube had died of old age! > > Not old age, but more likely the effects of exposure to chlorine which > can harden and crack rubber. > > Multiple articles on the effects of chlorine on rubber: > > > Thanks to water chlorination, all the rubber seals and faucet gaskets > in my house last about 25 years. Over the years, I've seen a few > damaged rubber valve stems on cars and bicycles stored near clothes > washing and swimming pool chlorination machinery. The bleach (sodium > hypochlorite) used in washing condenses on everything and eventually > hardens rubber compounds. > > The good news is that it takes many years for the rubber to harden and > crack. Viton(FKM) fluorocarbon rubber seals are a big improvement: > > I have NOT found any bicycle inner tubes or valve stems made from > Viton(FKM): > > However, one can buy blue Viton (FKM) valve cores for about $2/ea: > > > While I don't doubt you regarding chlorine (and both ozone and UV also degrade the rubber in our tires/tubes), the base of a bicycle tube valve has absolutely minimal exposure. A mechanical cause (abrasion, rim liner issues, low pressure) is much more probable. -- Andrew Muzi am@yellowjersey.org Open every day since 1 April, 1971