27" frame, 700C wheels = brake problem

Discussion in 'Cycling Equipment' started by RutgerBeij, Jul 6, 2006.

  1. RutgerBeij

    RutgerBeij New Member

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    I have a Raleigh 531 frame made for 27" wheels. I want to upgrade to a Shimano Tiagra 9 speed gear system, but this only seems to be possible with 700C wheels. Unfortunately, I can't find brakes which have a long enough drop to accomodate the change in wheel size.
    Can anyone offer a solution?
     
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  2. alfeng

    alfeng Well-Known Member

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    What's wrong with the brakes that are on the frame, now? Or, did you get the frame without brake calipers?

    Well, Tektro makes a "long reach" dual-pivot brake ... Shimano makes a "long reach" dual-pivot brake ...

    OR, if your frame has brake calipers still attached to it, you should be able to adjust them to use with 700c wheels ... just change the brake pads if they aren't giving you enough stopping power.

    BTW. If those aren't long enough (!?!), then you'll have to resort to BMX brake calipers ...
     
  3. RutgerBeij

    RutgerBeij New Member

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    Brakes on the frame are shimano long reach(49-57mm)they fit perfectly on the 27'' wheels that are on the bike, but if I change to 700c, the brakes will reach to the gap between the tyre & the rim.

    I will look into using BMX calipers as you suggest, it sounds like that might work well.

    Thanks for the suggestion!!
     
  4. John M

    John M New Member

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    You can have wheels made with Tiagra (or any other "modern") hubs and 27" rims. This is pricier than getting pre-built wheels, which are primarily going to be 700c these days. $35-45/wheel labor + parts or maybe a good opportunity to learn to build your own, then the cost is parts + maybe 3-4 hrs/wheel for a first time wheelbuilder.

    Another possibility is to get or make "drop bolts" to allow your brakes to extend their reach.

    Harris cyclery used to carry them, but apparently their supplier no longer stocks them. Their website has some instructions to make your own.

    http://www.sheldonbrown.com/dpdropbolt.html

    I bet that alfengs suggestion of using a long reach brake will work with standard 700c wheels. Whereas a BMX type brake would stop your bike, I can't think of anything less suited for a classic 531 frame
     
  5. alfeng

    alfeng Well-Known Member

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    I have to agree! The BMX brake was mentioned ONLY as a last resort ... and, would be butt-ugly on your 531 frame.

    Without a direct comparison at the moment, I think the Tektro 521A is as long (something like a 69mm reach ... oops, I just looked it up and it is spec'd at only 57mm ... are you sure your current brake calipers won't reach?) as my "old" (I mean really old ... vintage from the 70s) Dura Ace calipers (the former "normal" reach) which I am pretty sure are almost as-long-as-or-the-same-as my Mafac Racer calipers (which I know could be readily used on an old Gitane on which I swapped between the 27" wheels it came with and some 700c wheels).

    The Shimano "long reach" dual-pivot brake calipers certainly have as long a reach as the Tektro BUT will undoubtedly cost 2x as much.
     
  6. garage sale GT

    garage sale GT New Member

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    I am currently upgrading a 27" Schwinn World Sport to take 700C wheels, although it is more of a "2200" type of machine than a "tiagra"! :D

    There may not be enough room for a drop bolt since you only need to drop your brakes down 4 mm.

    The brake fixing bolt would have to pass through the part of the frame which forms the bottom of the current brake fixing hole.

    Try looking up some touring brakes online. They have to have extra reach. They go on 700X37 tires or larger.
     
  7. dgregory57

    dgregory57 New Member

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    You could take a small file and extend the slot in your brake calipers.

    I have read (and it makes sense) that the caliper arm beyond the brake shoes is not necessary for strength, so getting the additional few mm of reach shouldn't hurt the brakes, and they should work as well for 700c as they do for 27 inch.
     
  8. fish156

    fish156 New Member

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    Long reach brakes may, or may not, work - it depends on the frame. Usually the rear brake is the one that gives the most problems, due to the position of the seat stay brake bridge on the frame. There are "ultra" long reach brakes available for worst cases. Although they do not show up on the Harris site, if you call them they have these ultra-long reach brakes. They are no-name Shimano knockoffs and sell for (IIRC) $50 for a front and rear pair. I am using one on a rear and it works fine. Harris told me it might be a little "soft", but I have not noticed this.

    As someone mentioned above, the custom drop-down bolts once sold by Harris are not availble. I had tried to buy one and they steered me to the ultra-long reach calipers. These are a lot cheaper than the dropdown bolts so it's kind of a no brainer, and, a much more elegant solution. Pick up the phone and call Harris.
     
  9. DiabloScott

    DiabloScott New Member

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    I counsel for new 27" wheels. All those other ideas are kludges. 27" rims and tires are easy to find on the web so the only downside is a few days time for replacements if you need them.
     
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