Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Port Rocket-Sauce's Avatar
    Join Date
    Jan 2008
    Location
    Boston
    My Bikes
    1990 Fuji Ace, 1990 Bridgestone RB-1, 1995 Independent Fabrications Track, 2005 Calfee Dragonfly Pro
    Posts
    5,050
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)

    Adding Disc Brake Tabs to Road Frame

    The best man from my wedding is looking for a lugged steel road frame with racy geometry that can have disc brakes. I'm looking for a fun winter project and would like to surprise him. I have two frames in mind, both similar quality: nice but not too nice. I have a 700c disc fork ready to go. I just need to get the disc brake tab, reinforcing strut and cable guide brazed on to the rear.

    My question for you all is: Is this a tough job? I have heard from a few interested local frame builders and they either won't work on anything but their own frames or all quote ~$200+. That may be the going rate, but it puts the whole project over budget. Is that reasonable?

    Are there any other options? Like going to a welding shop? I know this is a long shot, but felt I had to ask. I don't want to be cheap, just want to understand the cost. How labor intensive is this? I understand it requires more precision than adding, say, a cable guide, but the cost differential seems pretty high ($25 for the cable guide vs $175 for the brake tab).


    THANKS

  2. #2
    Senior Member
    Join Date
    Feb 2011
    Location
    Minnesota
    My Bikes
    N+1=4
    Posts
    1,587
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Rocket-Sauce View Post
    The best man from my wedding is looking for a lugged steel road frame with racy geometry that can have disc brakes. I'm looking for a fun winter project and would like to surprise him. I have two frames in mind, both similar quality: nice but not too nice. I have a 700c disc fork ready to go. I just need to get the disc brake tab, reinforcing strut and cable guide brazed on to the rear.

    My question for you all is: Is this a tough job? I have heard from a few interested local frame builders and they either won't work on anything but their own frames or all quote ~$200+. That may be the going rate, but it puts the whole project over budget. Is that reasonable?

    Are there any other options? Like going to a welding shop? I know this is a long shot, but felt I had to ask. I don't want to be cheap, just want to understand the cost. How labor intensive is this? I understand it requires more precision than adding, say, a cable guide, but the cost differential seems pretty high ($25 for the cable guide vs $175 for the brake tab).


    THANKS
    Disc brakes change the whole stress profile on the frame. It's not as simple as just welding on the brake mounts. I think the $200 is more than reasonable (bargain) but I'd be cautious (as in run the other way) about anyone that is just going to attach the brake mounts and be done. Anyone who would do this properly would need to evaluate what the frame is built to do now and what other changes it would need. So it's not about just knowing how to attach the mounts, it's about knowing where, how and if the frame can handle it that matters.


    J.

  3. #3
    Randomhead
    Join Date
    Aug 2008
    Location
    Happy Valley, Pennsylvania
    Posts
    12,957
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    $200 is reasonable. Although I'm wondering if it can be done at all

  4. #4
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    4,348
    Mentioned
    56 Post(s)
    Tagged
    0 Thread(s)
    Wheels Built Up With Drum Brake Hubs Retrofit Nicely without Frame Modifications , and have a Much Longer Service Free Life than Disc Brakes Too.
    Last edited by fietsbob; 01-15-15 at 06:45 PM.

  5. #5
    Senior Member
    Join Date
    Dec 2010
    Location
    Above ground, Walnut Creek, Ca
    My Bikes
    7 single speed road
    Posts
    4,742
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    is it demonstrably different, as regards stresses, than running a coaster brake with an arm attached to only one chainstay?

    BTW, 200 doesn't seem out of line, although it may well be out of one's budget. could just run a caliper in back and convince the best man that he's not that good.

  6. #6
    Senior Member
    Join Date
    Oct 2007
    Location
    West Yorkshire, United Kingdom
    Posts
    3,676
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    From a non-frame builder, but technical perspective, what are you going to do about the spacing? Most all disc hubs are currently 135mm rear (many are wide, very few are 130mm) and road bikes are most commonly seen with 130mm rear OLD. Will the frame take this spreading?

  7. #7
    Randomhead
    Join Date
    Aug 2008
    Location
    Happy Valley, Pennsylvania
    Posts
    12,957
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    when I said it might not be able to be done, I meant it might not fit. I am almost positive it isn't going to fit on the chainstay.

  8. #8
    Senior Member
    Join Date
    Jan 2013
    Posts
    179
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    This ^. Stick a disc wheel in the frame and make sure the disc clears the stay before doing anything else.

  9. #9
    Senior Member squirtdad's Avatar
    Join Date
    Jul 2006
    Location
    San Jose (Willow Glen) Ca
    My Bikes
    '89 Miyata 1400, '82 nishiski (current utilty/commuter project)
    Posts
    3,391
    Mentioned
    9 Post(s)
    Tagged
    0 Thread(s)
    '82 Nishiski commuter/utility
    '83 Torpado Super Strada ... cafe commuter
    '89 Miyata 1400
    Soma rush Fixie
    '78 Univega gran turismo (son's Fixie/SS)
    06 Haro x3 (son's bmx)
    Electra cruiser (wife's bike)

    looking for: De Rosa 58cm ELOS frame and fork internal cable routing

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •