- TheThinkTank - lists.bikecollectives.org

New Orleans/Gulf Cost Folks OK?
by Jay Varner 05 Sep '08

05 Sep '08

Just checking in. I realize email might not be the best way to reach ya'll...but if you do get this, let us know if we can help. In solidarity, Jay Sopo Bikes, Atlanta sopobikes.org

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Re: [TheThinkTank] Frozen seatpost - stem removal tips by Jobst Brandt
by dragonfly＠mac.hush.com 04 Sep '08

04 Sep '08

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Kyle McKinley, I love that I can open an e-mail and read that anyone is someone's "favorite living bicycle thinker". Thank you for having a catagory of "bicycle thinkers" in your head, for having favorites, and for having so many favorites that they must be subcatagorized into "living" and, presumably, "dead" 'bicycle thinkers'. Reading your post cheered me up and made me feel that the world is a good place. I think I'll go read Mr. Brandt on wheels right now. It just became the most important thing on my to-do list. Kudos to all Americans for your historic Presidential slate-- Obama-Biden, McKinney-Clemente, Nader-Gonzalez, even McCain-Palin, despite the shudder that one gives me--has everyone seen the photos of Barak Obama riding his bike around Chicago like a regular commuter cyclist? Sasha On Sat, 30 Aug 2008 16:48:30 -0400 kyle mckinley <bicirider(a)gmail.com> wrote: >Mr. Brandt is my favorite living bicycle thinker. His posting on >wheels >(fully catalogued on the web) make for incredibly interesting and >entertaining reading. Unlike most everyone else out there, Brandt >is a >engineer, with no links to the industry. He's exactly the kind of >grumpy old >codger that we need in this scene, and I've never known him to be >wrong. >Thanks for these reposts... His gruff responses make me laugh out >loud. >-kyle > > >On 8/6/08, Mark Rehder <mark(a)re-cycles.ca> wrote: >> >> Speaking of Jobst, he has an FAQ on Sheldon's site: >> >> http://www.sheldonbrown.com/brandt/index.html >> >> Lots of good reading (and opinions) there. >> >> Mark Rehder >> http://re-cycles.ca >> _______________________________________________ >> Thethinktank mailing list >> Thethinktank(a)bikecollectives.org >> >> http://lists.bikecollectives.org/listinfo.cgi/thethinktank- >bikecollectives.org >> > > > >-- >If an Easyrider rides easy, then a bicirider rides bicis -----BEGIN PGP SIGNATURE----- Note: This signature can be verified at https://www.hushtools.com/verify Charset: UTF8 Version: Hush 3.0 wkYEARECAAYFAki59DwACgkQ5O7ahKJmrRl0sACfeK2qRqONK7S6floCo+OhCrYjAMYA njJOkg1q8nCajAql7ZZqaSYTutwf =/gpi -----END PGP SIGNATURE-----

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Re: [TheThinkTank] New Orleans/Gulf Cost Folks OK?
by dragonfly＠mac.hush.com 02 Sep '08

02 Sep '08

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I second that; when things settle down, please let non-locals know how we can help. You are all in everyone's thoughts and prayers. Sasha On Mon, 01 Sep 2008 23:58:04 -0400 Jay Varner <jay(a)sopobikes.org> wrote: >Just checking in. I realize email might not be the best way to >reach >ya'll...but if you do get this, let us know if we can help. > >In solidarity, >Jay >Sopo Bikes, Atlanta >sopobikes.org >_______________________________________________ >Thethinktank mailing list >Thethinktank(a)bikecollectives.org >http://lists.bikecollectives.org/listinfo.cgi/thethinktank- >bikecollectives.org -----BEGIN PGP SIGNATURE----- Note: This signature can be verified at https://www.hushtools.com/verify Charset: UTF8 Version: Hush 3.0 wkYEARECAAYFAki9EN8ACgkQ5O7ahKJmrRlZLQCcCkqBsJV5AffBp3T/7Y7vvhNJnukA oLibxHQVqVz2E20MY7dG2LvRmEu3 =R+Tb -----END PGP SIGNATURE-----

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Frozen seatpost
by BovineOaks＠aol.com 31 Aug '08

31 Aug '08

Friends I have removed many seat posts that bike shops could not get out, I have tried many chemicals, saw blades, oxy/acetyl torch. I have witnessed frame builders and frame painters melt them out with torches. If you get lucky and have very little corrosion you can put a bike upside down in a bench vice clamping on the seat post. If you have lots of corrosion that extends 4 to 6 inches down the seat post, Chemistry will not eat down 4 inches in less than a year. I have only seen the erosion of a few millimeters of the oxidation with chemical remedies. This will work if you are lucky and have very little corrosion. When you are not lucky then a long saw blade used mindfully will cause the least amount of damage to the bike frame. If you are going to repaint the bike then using an oxy/acetyl torch will melt the aluminum seat post out of STEEL BIKE FRAMES ONLY. The heat will destroy the paint and the torch is placed inside the seat post not outside on the frame seat tube. If too much heat is used the seat tube will crack or the seat stays will become unbrazed. Great care is needed and a bunch of skill if you are to use a torch. Cold works best if the seat post is not inside the seat tube. When they are bound together tightly they are hard to cool at different rates. When they are cooled at the same rate they stay bound together. Once again if there is very little corrosion binding the two together, cooling may work. The saw works the best for the least amount of damage to the frame. It is slow going and hard work, but it works every time. Christopher Wallace Chicago **************It's only a deal if it's where you want to go. Find your travel deal here. (http://information.travel.aol.com/deals?ncid=aoltrv00050000000047)

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Re: [TheThinkTank] Frozen seatpost - stem removal tips by Jobst Brandt
by Andrew Bushaw 31 Aug '08

31 Aug '08

I have run into this a few times with aluminum seatposts/steel frames. I've tried the ammonium route before but found it much to stinky/messy and didn't get results. I have had success with a sheldon method of taking a longish hacksaw blade and cutting a vertical slit in the seatpost from the inside, stopping once you get near the frame. Then I grabbed onto it with a monkey wrench and it just sort of collapsed into itself as I twisted it. Very, very time intensive but effective. I've also heard the CO2 heating/cooling trick works as well. -Andrew FM Community Bicycle Workshop thethinktank-request(a)bikecollectives.org wrote: > Send Thethinktank mailing list submissions to > thethinktank(a)bikecollectives.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.bikecollectives.org/listinfo.cgi/thethinktank-bikecollectives.… > > or, via email, send a message with subject or body 'help' to > thethinktank-request(a)bikecollectives.org > > You can reach the person managing the list at > thethinktank-owner(a)bikecollectives.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Thethinktank digest..." > > > Today's Topics: > > 1. Re: Frozen seatpost - stem removal tips by Jobst Brandt > (Rigel Christian) > 2. Re: Frozen seatpost - stem removal tips by Jobst Brandt > (Arlen Cooke) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 30 Aug 2008 21:33:09 -0700 > From: "Rigel Christian" <rigelc(a)gmail.com> > Subject: Re: [TheThinkTank] Frozen seatpost - stem removal tips by > Jobst Brandt > To: "The Think Tank" <thethinktank(a)bikecollectives.org> > Message-ID: > <d47aa47d0808302133h343be5bcm4f56b1b27876d95b(a)mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > the people on the framebuilders list suggest two things when everything else > has failed: > > 1) ammonia > 2) lye (red devil has been removed from the market because of meth hysteria, > but drano works - anything with sodium hydroxide as the primary ingredient) > > these work for aluminum-seatpost-with-steel-frame only, AFAIK. the latter > will actually eat away at the seatpost itself (and produce probably-nasty > fumes). the former stinks really bad. > > i have never tried either of these, but they seem reasonable from a chemical > standpoint. > > On Sat, Aug 30, 2008 at 9:08 PM, Ethan <elabowitz(a)gmail.com> wrote: > > >> For a seatpost (or any aluminum part that fits into a steel tube), I would >> think one would prefer to cool down the offending aluminum seatpost rather >> than heat the (painted steel) seat tube. >> >> Cool seatpost = smaller seatpost, ya? >> >> I hear this can be done with a CO2 cartridge, but I've never had to try it. >> >> Ethan >> Richmond, VA >> -- >> http://bikebuilding.blogspot.com >> >> >> On Sat, Aug 30, 2008 at 11:42 PM, joshua muir <muirjoshua(a)gmail.com>wrote: >> >> >>> I didn't see anything abut heat in there- I have had a fair bit of success >>> heatng stuck joints, and pulling stuck aluminum stems and seat posts. >>> >>> just don't overheat (or use the auluminum parts again). >>> >>> josh >>> >>> >>> On Sat, Aug 30, 2008 at 6:30 PM, <dragonfly(a)mac.hush.com> wrote: >>> >>> >>>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA1 >>>> >>>> >>>> Kyle McKinley, I love that I can open an e-mail and read that >>>> anyone is someone's "favorite living bicycle thinker". >>>> >>>> Thank you for having a catagory of "bicycle thinkers" in your >>>> head, for having favorites, and for having so many favorites that >>>> they must be subcatagorized into "living" and, presumably, "dead" >>>> 'bicycle thinkers'. >>>> >>>> Reading your post cheered me up and made me feel that the world >>>> is a good place. >>>> >>>> I think I'll go read Mr. Brandt on wheels right now. It just >>>> became the most important thing on my to-do list. >>>> >>>> Kudos to all Americans for your historic Presidential slate-- >>>> Obama-Biden, McKinney-Clemente, Nader-Gonzalez, even McCain-Palin, >>>> despite the shudder that one gives me--has everyone seen the photos >>>> of Barak Obama riding his bike around Chicago like a regular >>>> commuter cyclist? >>>> >>>> Sasha >>>> >>>> >>>> On Sat, 30 Aug 2008 16:48:30 -0400 kyle mckinley >>>> <bicirider(a)gmail.com> wrote: >>>> >>>>> Mr. Brandt is my favorite living bicycle thinker. His posting on >>>>> wheels >>>>> (fully catalogued on the web) make for incredibly interesting and >>>>> entertaining reading. Unlike most everyone else out there, Brandt >>>>> is a >>>>> engineer, with no links to the industry. He's exactly the kind of >>>>> grumpy old >>>>> codger that we need in this scene, and I've never known him to be >>>>> wrong. >>>>> Thanks for these reposts... His gruff responses make me laugh out >>>>> loud. >>>>> -kyle >>>>> >>>>> >>>>> On 8/6/08, Mark Rehder <mark(a)re-cycles.ca> wrote: >>>>> >>>>>> Speaking of Jobst, he has an FAQ on Sheldon's site: >>>>>> >>>>>> http://www.sheldonbrown.com/brandt/index.html >>>>>> >>>>>> Lots of good reading (and opinions) there. >>>>>> >>>>>> Mark Rehder >>>>>> http://re-cycles.ca >>>>>> _______________________________________________ >>>>>> Thethinktank mailing list >>>>>> Thethinktank(a)bikecollectives.org >>>>>> >>>>>> http://lists.bikecollectives.org/listinfo.cgi/thethinktank- >>>>>> >>>>> bikecollectives.org >>>>> >>>>> >>>>> -- >>>>> If an Easyrider rides easy, then a bicirider rides bicis >>>>> >>>> -----BEGIN PGP SIGNATURE----- >>>> Note: This signature can be verified at https://www.hushtools.com/verify >>>> Charset: UTF8 >>>> Version: Hush 3.0 >>>> >>>> wkYEARECAAYFAki59DwACgkQ5O7ahKJmrRl0sACfeK2qRqONK7S6floCo+OhCrYjAMYA >>>> njJOkg1q8nCajAql7ZZqaSYTutwf >>>> =/gpi >>>> -----END PGP SIGNATURE----- >>>> >>>> _______________________________________________ >>>> Thethinktank mailing list >>>> Thethinktank(a)bikecollectives.org >>>> >>>> http://lists.bikecollectives.org/listinfo.cgi/thethinktank-bikecollectives.… >>>> >>>> >>> >>> -- >>> >>> Joshua Muir >>> joshua(a)santacruzhub.org >>> >>> Frances Cycles -- francescycles.com >>> Handbuilt cycling framesets >>> Touring, Track, Road,Cross, and Cycletrucks for hauling any distance >>> >>> >>> The Bicycle Church Collective >>> Community Self-Service Cycle Repair >>> 3pm to 7pm everyday except Sunday >>> 703 Pacific Ave (enter on Spruce St) >>> Santa Cruz, CA 95060 >>> (831) 425-2453 >>> >>> _______________________________________________ >>> Thethinktank mailing list >>> Thethinktank(a)bikecollectives.org >>> >>> http://lists.bikecollectives.org/listinfo.cgi/thethinktank-bikecollectives.… >>> >>> >>> >> _______________________________________________ >> Thethinktank mailing list >> Thethinktank(a)bikecollectives.org >> >> http://lists.bikecollectives.org/listinfo.cgi/thethinktank-bikecollectives.… >> >> >> >

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Frozen seatpost - stem removal tips by Jobst Brandt
by Tim Potter 30 Aug '08

30 Aug '08

Folks, My head mechanic has fwd'd me the following collection of posts from one of the top bike mechanics/ authors in the country (Jobst is the author of "The Bicycle Wheel" considered the bible of everything you ever wanted to know about bike wheels). Apparently my advice doesn't apply to any aluminum parts (seatposts/ stems). Reading thru these posts is very enlightening and should be required reading if you're a mechanic or shop estimator dealing with customers. Tim ----------------- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: stem stuck... please help! Date: 3 Sep 1998 15:46:27 GMT Jim Robin writes: > My Bianchi's handlebar stem is stuck inside the fork steerer tube. > The stem is a standard aluminum quill-type (TTT Synthesis). I > loosened the quill hex bolt and sprayed WD-40 in hopes of freeing it > up, but no luck. If you have loosened the bolt and driven the expander cone out of engagement with the bottom of the stem, the stem should be rotatable with moderate force. If this is not the case, then you have a corroded frozen stem. Many forks have been damaged by twisting the bars forcefully in an attempt to free the stem. Don't do it. A skilled mechanic can drill out the stem until it is a thin shell, then with a grinder. break through one side of the shell to extract the stem. Because aluminum expands with corrosion, you cannot loosen a frozen stem by force. Get it removed by a competent shop. Frame builders do this regularly. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Frozen Stem Date: 7 Nov 1998 20:22:20 GMT Tom Gargulak writes: > My aluminum handlebar stem is frozen into my steel frame due to > corrosion. We tried penetrating oil and force. Any tips or a FAQ? The advice to: "Twist, twist, twist. It will eventually break free." Is not good. THe result of this method is often fork failure unless you use a 2x4 through the crown of the fork, and then success is rare. There are no solvents for the aluminum oxide that has expanded with more force than you can imagine. Steel tube swimming pool railings often expand by 1/8 inch from aluminum plugs in the ends that leaked. The best solution is to saw off the stem, drill out to as close to the steer tube as possible and use a Dremel tool to grind it through on one side. The local frame builder has a collection of these shells in a heap. The cause of these failures is that the stem is only anchored at the bottom and works from side to side in use at the top, where a meniscus of sweat or sweat loaded rain water waits to enter. Even the rubber seals in some head bearing lock nuts are usually not good enough to block intrusion. I have a stem with an extension protruding above the lock nut with a clamp on it. By this method the stem is held top and bottom and a fill of grease on installation does the trick as it does on seat posts. It's the motion that kills the stem. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.misc Subject: Re: stuck seatpost dilema Date: 11 Jan 2000 15:52:27 GMT Doug VanGoethem writes: > I have a 10 year old steel frame bike that I still use for commuting > and such. I was going to let someone else ride it and found the > seatpost was firmly stuck. It's not a surprise when I think about > it because it has to have been at least 3 years since I moved it > last and who knows if I had any grease on it then. [...] > So what's the deal? Is this just the worst stuck seatpost in history? Your tale of woe is not unusual and the advice you found in earlier writings is mostly malarkey, invented by readers who are hypothesizing or who had seat posts that were basically a tight fit but not corroded in place. When aluminum (seatpost or bar stem) oxidizes from water intrusion, it has both galvanic activity and a captive electrolyte (water) source. Aluminum oxide formed is porous and hard and takes up about twice the volume of the metal from which it is made. This is a press fit with molecular interlocking that cannot be separated by force and cannot be dissolved by chemical action in any reasonable time without immersion in a hot bath. Even that is doubtful because the area of attack is small and depth great. The practical way for removing such corroded parts is to saw them off and bore them out, first with a drill if wall thickness is too great (bar stem), and then with a Dremel tool. For prevention of this effect, make sure the seat post is sealed with stiff grease or paint. Bar stems are always vulnerable if they are not double clamped because they pump water by a varying gap when you wrench on the bars. Road bikes traditionally have an expander that arrests the bottom of the stem while the top is free to move laterally in the upper end of the steer tube. Only stems clamped at the upper end can be effectively sealed. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.misc Subject: Re: stuck seatpost dilema Date: 12 Jan 2000 02:09:06 GMT Mike Jacoubowsky writes: >> Your tale of woe is not unusual and the advice you found in earlier >> writings is mostly malarkey, invented by readers who are >> hypothesizing or who had seat posts that were basically a tight fit >> but not corroded in place... > I don't know if you're just trying to be contrary or mean or > whatever, but not all of the advice in the other posts was > "malarkey" (of course, you did say "mostly"...). You are correct in > your technical assessment of what causes the problem, but you are > incorrect to *assume* that the problem has progressed to the point > where the methods suggested wouldn't work. Ice water, LPS-4, WD-40 or vinegar are all theoretical methods. I have seen these attempted by people who believed in them without success. After the aluminum part was removed by drill and grind, the interface showed no sign of penetration in spite of laborious applications of said elixirs. On the other hand, I have seen forks ruined by twisting on handlebars in an attempt to remove a frozen stem. This is the more common result when a stem has corroded. > Have I seen a stuck stem which I could *not* remove using the means > I described? Absolutely. Probably three of them in 20+ years. > Have I successfully removed a great many others that people had > given up on? Yes! As I said, the ones that came out were not a result of mystical fluids but rather brute force. I didn't notice what method you claim worked for you. I also have removed stuck parts, but it wasn't with liquid nitrogen, ice or WD-40. These methods are holding out false hope for people who are not going to get served any better than by trying force up to a safe limit and then grinding the part out. > I don't know if you're just trying to be contrary or mean or > whatever, but not all of the advice in the other posts was... I think holding out false hopes is far more unkind than to tell the reader the truth. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: stuck seatpost dilema Date: 11 Jan 2000 19:03:21 GMT Matt O'Toole writes: > What about headsets with O-ring seals around the top to prevent > water from seeping between the stem and steerer? Do they not work? They haven't for me even with plenty of grease. My steer tube extends through the top nut with a stainless steel clamp. This no longer pumps and doesn't corrode, but then I'm using a steel stem now. The decapitated aluminum ones are hanging on the wall. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 27 Apr 2001 16:51:59 GMT Tim McNamara writes: > In a roundabout way I am asking whether steel stems are less likely > to get stuck in the steerer than alloy stems because of the galvanic > corrosion issue? In which case I lucked out... As I mentioned, steel stems do not get stuck and that is why that stem attachment was accepted in its day. The onset of aluminum stems caused the frozen stem syndrome. Creaking stem has always been a problem and the top clamp was devised to get rid of that. Let's not get the cause and effect sequences mixed. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 27 Apr 2001 18:11:39 GMT Jon Isaacs writes: >> That was before they thought of the O-ring Band-Aid that did no >> good. Pumping from side to side, the O-ring reduced water >> intrusion only slightly over no O-ring. > I cannot say whether or not the O-ring seals are properly designed > in the head set in question, however it is certainly possible to > design an O-ring seal which will work under such conditions. At the risk of being excessively repetitive, O-rings don't work well in lateral displacement, a mode in which they pump. Shimano and Campagnolo lock nuts with O-rings did not prevent water intrusion although their existence should make it obvious that there is a problem, something manufacturers don't mention. See, for instance, introduction of Campagnolo's "differential" brake. What a sham. > However, I suggest that if someone is really concerned with this > problem, a gator made with carefully applied Scotch 33 tape or > better yet an old inner tube and some zip ties would make a > sufficient seal. That might be a clumsy temporary fix but the design of this interface is basically flawed and the advent of aluminum stems brought it to it's knees for those of us who ride a lot. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 24 Apr 2001 01:15:59 GMT Mike Latondresse writes: > I won't say I have commuted to work by bike for 10+ years in > Vancouver BC where it sometimes rains in the winter and have never > had a stuck stem. I repeat that a minimum of preventive eminence is > all that it takes so negligence, not shit, is the issue. Of your 8 > points in support of this over-the-horizon advantage, number 1 seems > to be mainly a problem dogging you and some of your friends and not > the common experience of this group, and the other 7 are somewhat > dubious to me as a rider. For example who cares about a > Road/MTB/tandem standard, road riders? Oh! So what do you propose one should do, take the stem out every couple of weeks in the winter and minister to it? I can assure you that I lost a stem on a trip in the alps in less than three weeks, climbing in the rain often. When I came home, the stem was solid. I had installed it with grease before the trip. I don't understand what you and those of your ilk get out of defending poor designs on bicycles other than that you have a religious belief that if the bicycle gods made it it must be right. Therefore, anyone who has problems is a sinner to be roundly chastised. There's more to bicycling than commuting in the rain. It might just be that your experience is so narrow that you cannot visualize any other form of use. That would be the kinder assessment of your accusations. If that is not the case then you are guilty of greater social faux pas, namely righteous pomposity. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 25 Apr 2001 17:42:31 GMT Jay Beattie writes: > Everybody knows that stem-stick can happen, but after only three > weeks for Jobst's and one week for Johan? I wonder whether there is > some other environmental factor at play, such as salt or something > else that speeds corrosion. Hold it! I thought this thread was about riding bicycles, riding that for active bicyclists involves enough sweat to cover the front of the bicycle with salt crystals. Maybe some riders never ride harder than what their mascara will sustain without running, but for those who still have a little youth, that doesn't work. I know of one local rider who was saved by titanium because everything else turned to rust and aluminum oxide under his nose. > Ordinary rain certainly isn't the kiss of death because I ride in > the rain on an every-other-day basis during the winter and spring, > do little maintenance (shame on me) and rarely get significant > sticking. The rain serves to wash the salt into the places where it can do some "good". Climbing hills in the rain can do both. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 25 Apr 2001 17:30:22 GMT Lincoln Dickerson writes: > I am not sure where to interject this idea into this thread but this > seems as good a place as any. The O-ring idea gave me a thought and > maybe it is not mechanically sound either but here goes. > Would it be possible to use a boot like on a CV-Joint? So that the clamp > would keep the water from traveling down the stem and causing it to get > inside. > This of course would not be necessary for everyone because many people > don't have any problem but for those that do would it work? This ignores the basic problem, which is, that this is a mechanically flawed joint. Forget about the water intrusion. Stems break off and creak because they are attached only at the bottom end, being free to fret and gnaw at the top of the steer tube. I have cracked off stems and had ones with wear grooves at the steer tube exit. This is not a new problem but with the advent of the aluminum stem it got more evident. In the days of yore, track bicycles had an expander at the bottom and a clamped steer tube at the top so the stems wouldn't yaw in the steer tube. I have such a clamp on my fork and it does the job. No water will go in there just as no water goes down my seat tube because it is not a dynamic joint anymore. A little grease on installation takes care of it. > Maybe we could figure out which stem and frame combinations have the > most trouble. Or those with a particular riding style or environmental > or terrain issue. > What do you think? > I am not sure this would be any better looking than a threadless stem > but maybe it would save a lot of effort and stems. Threadless stems are made in different sizes and can be made as neat and clean as any. They probably won't look like a 1980's Cinelli stem but that is purely fashion. I prefer function. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 26 Apr 2001 01:07:37 GMT Richard Ney writes: >> In the days of yore, track bicycles had an expander at the bottom >> and a clamped steer tube at the top so the stems wouldn't yaw in >> the steer tube. I have such a clamp on my fork and it does the >> job. > Are you saying that you have clamped a short section of steerer tube > around the stem above the headset? Yes. > I'm unclear about what you've done here. You described it. >> No water will go in there just as no water goes down my seat tube >> because it [the stem] is no longer a dynamic joint. > How is the seat-tube/seat-post not a dynamic joint anymore? What did you > do? The seat post is static. It is the stem that becomes static with a top clamp. If you look at the interface, you will find a nice meniscus of dust encrusted grease with no witness crack from motion in contrast to a typical quill stem, or pedal for that matter that always fret and pump. We've been through the pedal being a dynamic joint recently. That's why we have a left hand thread on the left pedal and why cranks break predominately there. It is a dynamic joint. Seat posts are static joints on most bicycle because they have a good clamp and contact diameter, as is noticeable when installing the post in the frame. Stems visibly move when handlebar forces are applied. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 26 Apr 2001 15:49:43 GMT Richard Ney writes: >>>> In the days of yore, track bicycles had an expander at the bottom >>>> and a clamped steer tube at the top so the stems wouldn't yaw in >>>> the steer tube. I have such a clamp on my fork and it does the >>>> job. >>> Are you saying that you have clamped a short section of steerer tube >>> around the stem above the headset? >> Yes. >>> I'm unclear about what you've done here. >> You described it. > How do you actually secure the steerer section to the stem? What > sort of clamp are you using? An unthreaded and split length of steer tube extends beyond the conventional head bearing lock nut and a stainless steel clamp locks it. It is so inconspicuous that no one notices it. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 26 Apr 2001 20:56:18 GMT Dave vt? writes: >> An unthreaded and split length of steer tube extends beyond the >> conventional head bearing lock nut and a stainless steel clamp locks >> it. >> Just sketch yourself a picture of what I just described. It can't be >> that difficult. The extension is smaller in diameter than the thread. > You are right, it's not difficult. Your last sentence confirmed my > suspicions. > I can imagine that the cost of machining this steerer must be much > higher than the standard steerer; that's probably why it's not in > widespread use. It's an answer to a question that is not asked very > often. We found it easier to turn the thread off than to make a clamp with threads. It costs nothing extra when the bicycle is being made. The same lathe operation that cuts the thread also turns the extended end. The whole frame is unavailable on the market, however, Cinelli track frames came standard with this design. This is not my invention. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 26 Apr 2001 21:06:53 GMT Scott Hendricks writes: > The reason folks are having a hard time imagining what you describe, > Jobst, is that many newer headset these days have lock nuts that > CANNOT be screwed down past the end of the steerer tube. I have a > bike w/ a sealed Ultegra headset, and the lock nut bottoms out on > the end of the steerer, and has a seal that is supposed to contact > the stem quill. So? You chuck it in the lathe and cut a clearance bore so the thread can pass through. This is a custom operation so don't restrict yourself to off the shelf thinking. > Older headsets had lock nuts that could easily be screwed down > beyond the end of the steerer. That was before they thought of the O-ring Band-Aid that did no good. Pumping from side to side, the O-ring reduced water intrusion only slightly over no O-ring. Jobst Brandt <jbrandt(a)hpl.hp.com> ---------------------------------------------------------------------------- ---- From: jbrandt(a)hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: Threaded vs. threadless Date: 26 Apr 2001 15:54:43 GMT Robin Hubert writes: >> Threadless stems are made in different sizes and can be made as >> neat and clean as any. They probably won't look like a 1980's >> Cinelli stem but that is purely fashion. I prefer function. > So, the question begs, Mr. Brandt, do you use a threadless system? I think you can deduce the answer from what I have written. My solution is older than the threadless headset. Jobst Brandt <jbrandt(a)hpl.hp.com> ******************** Tim Potter Coordinator MSU Bikes Service Center B10 Bessey Hall/ Michigan St. University Along the N. River Trail, 300 ft. west of Farm Ln. Bridge E. Lansing, MI 48824-1033 Ph: 517/432-3400 Fax: 517/432-2743 Email: bikes(a)msu.edu Web: www.bikes.msu.edu Home Dept: www.transportation.pp.msu.edu

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Check out my Facebook profile
by Vyki Englert 24 Aug '08

24 Aug '08

I set up a Facebook profile where I can post my pictures, videos and events and I want to add you as a friend so you can see it. First, you need to join Facebook! Once you join, you can also create your own profile. Thanks, Vyki Here's the link: http://www.facebook.com/p.php?i=201407367&k=Y3B5XWRYQVZM5F1CSB2XP4&r&v=2 ___________________ This e-mail may contain promotional materials. If you do not wish to receive future commercial mailings from Facebook, please click on the link below. Facebook's offices are located at 156 University Ave., Palo Alto, CA 94301. http://www.facebook.com/o.php?u=1443204419&k=dbb4a3

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non-program traffic during specific programs?
by veganboyjosh＠gmail.com 22 Aug '08

22 Aug '08

Howdy all. I'm wondering how some of you handle people regular, off the street/new volunteers traffic in your shops while there's a program going on. For example, our youth EAB class is going on, and someone rides by the shop, sees bikes on stands, and walks up with questions about our organization, what we are/do, etc. Or someone comes up with a broken brake cable/flat tire/etc. Do you turn them away and focus on the program going on? Do you allow the instructor/facilitators to become distracted and possibly involved in some convoluted thing that's gonna take a lot more work than was first thought? I feel bad when I'm in the middle of a class of kids, and someone comes up who's super excited about our mission and shop, and wants to chat and get into it with me about stuff completely unrelated to the ongoing youth class, and I can't give them the attention they deserve. Any thoughts? Policies about such? thanks! josh. Community Cycles.

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bike!bike! mailings
by Ann Altstatt 19 Aug '08

19 Aug '08

dear all, exciting news! information and registration packets for this falls' bike!bike! in san francisco will be in the mail shortly. to this end, if you wish to receive a packet and your projects address is not in the wiki directory or the boop (or is out of date, etc.. . .), please send me your address information. looking forward to seeing folks in september! thanks and thanks, ann altstatt (of bike church, santa cruz)

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call for bike curriculums in school districts?
by veganboyjosh＠gmail.com 12 Aug '08

12 Aug '08

Hey ThinkTankers, Raise your hand if you're excited about bikebike!... *raises hand* I'm working with a few other volunteers and a Boulder Valley School District staff member on getting together some kind of bike related curriculum into PE classes for Spring 09. We have some interested PE teachers, and they basically have some freedom to use whatever curriculum they feel best achieves/measures certain benchmarks for the students' progress. (Things like "can exercise at a moderate pace for 20 minutes or longer", "can balance appropriately", etc.) We are in touch with several Safe Routes to Schools people from across the country, as they seem to be very involved in most of the in-school curricula that we've come across. I'm interested in any of your experience(s) with this, either as a volunteer involved in a in-school program, or as a member of a bike collective doing work in schools. Who funds your programs? What is involved? What is the staff/volunteer/instructor load like? Do you have multiple schools that participate? We have some very lofty (albeit awesome) goals, and I'd like to temper these with some experience and realistic expectations. Right now, we're aiming the class at 6th grade students. If anyone is interested in hosting a similar program in their own location, please get in touch offlist, and I'll put together something to share. Thanks for any input. josh brown. community cycles, boulder, co

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