cold setting chainstays

Discussion in 'The Bike Cafe' started by backwards, Oct 29, 2009.

  1. backwards

    backwards New Member

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    where should i post this thread?

    i want to cold set a track frame to accept a larger diameter tire, i have an idea to set a hydraulic spreading attachment in between the chain-stays and GENTLY apply pressure with the hopes of dimpling the chain-stay tubes enough to accept a 700x32 tire.

    I took this idea to my LBS and they strongly discouraged this idea likening the tubes of a steel track frame to a coat hanger. long story short they said i would end up throwing my frame in the garbage.thats the last thing i want to do. does anyone have any suggestions or arguments for or against this plan aside from the coat hanger theory
     
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  2. alfeng

    alfeng Well-Known Member

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    I don't know if you would end up throwing your frame into the garbage after your misadventure, but if you have a TRUE track frame, then the odds of fitting a tire larger than -- OR, as large as -- 700x25 are slim ... and, even if you could fit that size tire into your frame, you won't be able to fit a tire as large as a 700x25 into the fork.

    Go onto eBay and buy a Motobecane SS cyclocross frame ... I don't know what the rear spacing is.

    OR, buy an older, 70s vintage frame and narrow the rear stays to 120mm spacing (presuming THAT is the spacing you want).

    As far as cold setting the stays (steel ONLY), you do not want to use anything other than your own upper body strength ... apply whatever you perceive to be 30 lbs. of force ... measure & repeat until the desired spacing is achieved.

    BTW. SURLY makes SS (flip-flop) hubs with wider flange spacing for use in 135mm & 130mm wide frames. The non-flip-flop MICHE Primato hub can be respaced for a 130mm frame.
     
  3. backwards

    backwards New Member

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    It's a bianchi pista not a highend trackframe just an off the shelf fixed gear. I love the bike and I don't want a new frame I am able to run cyclo cross tires at the very ends of the dropouts but it loses alot of its responsiveness I have a picture of the bike on my profile I guess I will run it like it is since all of the responces I get regarding this idea seem to be no. I wish one person was like " yes that sounds like a great idea." oh well.
     
  4. dhk2

    dhk2 Active Member

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    If I understand correctly, you are considering crushing the chainstays to accept a fatter tire. If the frame is made of thin-wall Cromo tubing, would say it's risky. Have never tried this myself, but seems that crushing the high-tensile tubing could cause a crack. Even if it didn't, would guess frame strength and life would be compromised by weakening the chainstays in a high-stress area just behind the bottom bracket.

    If it was a cheap and heavy 1020 mild steel frame might be tempted to try it, but not with anything good that I wanted to keep.
     
  5. pat5319

    pat5319 New Member

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    If it's steel no problem, I've cold set dozens. Even if you do it by hand they usually "come up" straight. If it's Aluminum forget it, it will lose at least half it's strength when it's bent. Ever wonder why Alu frames are always "crooked"?- They can't be re-aligned!!! Safely that is
     
  6. alienator

    alienator Well-Known Member

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    Since when are "all" aluminum frames crooked? That's a large statement to make.
     
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