Updating 1991 Miyata 914

Discussion in 'Cycling Equipment' started by wightmn, Aug 17, 2013.

  1. wightmn

    wightmn New Member

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    I have had this bike since new. Love the way it rides. I upgraded 3 years ago to a Trek Madone 5.1. It's a great bike, but I miss my old Miyata. I want to update components and wheels. It came with Shimano 105 seven speed. I really want to get this thing updated to Ultegra. My concerns are the rear stay spacing. To work, it will have to be spread a bit. Is this a problem with older steel frames? Not sure if it weakens the frame to spread or if this even a great idea. Any other things to consider that I'm missing? It's going to cost more to update than i paid for it, but we do funny stuff for things tied to our youth.

    Thanks for any opinions or info.

    Ted
     
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  2. vspa

    vspa Active Member

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    any pictures ?
     
  3. alfeng

    alfeng Well-Known Member

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    Re-spacing a steel frame's stays is not difficult, but it cannot be approached with abandon ...

    Whereas Sheldon Brown + others suggest using a physical lever to assist in spreading the stays one-at-a-time 'I' have found that only the frames made with the heaviest of "gas pipe" tubing need THAT kind of leverage ...

    FWIW. Here's what 'I' do ...

    1. remove the rear wheel from the frame
    2. measure the stays (a metric tape measure will be very beneficial) ...
    3. I then grab a dropout in each hand and pull with whatever you estimate to be about 30 lbs. of force ...
    4. measure -- the stays MAY have changed by less than 0.5mm!!!
    5. repeat & measure until the stays are 130mm apart
      • this will take much LESS time than you think
      • if you use external leverage & do each stay separately then you will need to check for equal spreading AND the process will actually take much more time than simply, repeatedly tugging on the two dropouts simultaneously

    Now, you will need to realign the dropouts so that they are parallel to the central plane of the bicycle frame ... the steel is softer-than-you-think!

    1. with two small pieces of scrap plywood, sandwich the dropouts
    2. take either a PIPE WRENCH or a reasonably sized crescent wrench & tweak the dropout with whatever you estimate to be ONLY ~5 lbs. of force
    3. assess -- install a rear derailleur which uses either a 5mm or 6mm Allen Wrench to secure the rear derailleur to the hanger AND put the Allen wrench in the receiving socket to assess for perpendicularity
    4. remove the wrench & tweak with LESS force as needed

    You want to align BOTH dropouts.

    DONE!

    Here's a pic of the rear of my mid-80s OLMO after I re-spaced the rear to 130mm ...
    [​IMG]

    YOU CAN DO IT, TOO!
     
  4. wightmn

    wightmn New Member

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    No pics of the 105 kit. Will have to take some before and afters.

    Alfeng, thanks for the info. Hadn't thought about the hangers. Makes sense though. Will go at it a little at a time.

    I need to get a little more methodical about this. At present, it's lots of ideas with little focus. Thinking of moving the Ultegra from the Trek to the Miyata. Then update the Trek. Need more of a plan I think.
     
  5. CAMPYBOB

    CAMPYBOB Well-Known Member

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    7-speed road spacing was either 125 or 126 MM. Modern 10 and 11-speed spacing is 130 MM...only 4 or 5 MM wider.

    Your frame is triple-butted chrome molybdenum and can generally be expected to weather the cold setting to the new, wider rear spacing without problems. While almost anyone can splay the stays and correct the dropout parallelism with a careful eye, a machinist's scale and a 12" adjustable (Crescent style) wrench the job is best left in the hands of the experienced if the owner is a mechanical klutz.
     
  6. cyclenthusias44

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    Please upload some pictures.
     
  7. dabac

    dabac Well-Known Member

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    I've never had much luck simply forcing stays apart. IME, they tend not to spread evenly.
    I put the main triangle of the frame on a table, with the stays protruding into the air. Then I insert a plank from the front of the bike until one end rests on the inside of the dropout and the middle of the plank rests against the seat tube.(add blocks as needed). Then I push against the forward end.
    Length of string around dropouts and head tube, measure towards seat tube to check alignment.
     
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