Results 1 to 7 of 7
  1. #1
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    77

    Clamping threads on threaded fork?

    I'm turning my old Bontrager into a SS/CX frankenbike. I tracked down an old threaded Tange Switchblade fork (bolt on crown/rigid fork) that has a long enough steerer that it could be used with a threadless headset IF I clamp on the threads. I know it's not optimal, maybe even not suggested, but anyone have any real world experience using a setup like this?

  2. #2
    drev-il, not Dr. Evil!
    Reputation: Drevil's Avatar
    Join Date
    Dec 2003
    Posts
    3,488
    Quote Originally Posted by jts628
    I'm turning my old Bontrager into a SS/CX frankenbike. I tracked down an old threaded Tange Switchblade fork (bolt on crown/rigid fork) that has a long enough steerer that it could be used with a threadless headset IF I clamp on the threads. I know it's not optimal, maybe even not suggested, but anyone have any real world experience using a setup like this?
    Yes. I clamped a threadless Control Tech stem onto a threaded fork that came with my crapola Specialized Hard Rock frame. The bike serves as commuter duty. HOWEVER, I don't know if I'd ride this bike down some narrow rocky trail. Seen below, with the blinding reflective stickers...
    Attached Images Attached Images

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    77
    Quote Originally Posted by Drevil
    Yes. I clamped a threadless Control Tech stem onto a threaded fork that came with my crapola Specialized Hard Rock frame. The bike serves as commuter duty. HOWEVER, I don't know if I'd ride this bike down some narrow rocky trail. Seen below, with the blinding reflective stickers...
    Thanks for the reply. I'm going to give it a shot. I'll try to keep the steerer length as short as possible to minimize thread overlap and see how it goes.

  4. #4
    drev-il, not Dr. Evil!
    Reputation: Drevil's Avatar
    Join Date
    Dec 2003
    Posts
    3,488
    Quote Originally Posted by jts628
    Thanks for the reply. I'm going to give it a shot. I'll try to keep the steerer length as short as possible to minimize thread overlap and see how it goes.
    Y'know, given a choice, I'd probably run the threaded headset and fork, then use an adapter like this to open up my stem choice. I was just being lazy and cheap (I already had a cheap threadless headset and old threadless stem), but if you feel the same way...



    Click on the pic for more choices.

    Another problem with clamping onto a threaded fork is that the threads dig into the stem.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    77
    Quote Originally Posted by Drevil
    Y'know, given a choice, I'd probably run the threaded headset and fork, then use an adapter like this to open up my stem choice

    Another problem with clamping onto a threaded fork is that the threads dig into the stem.
    Oddly enough, I already have one of those on the Bonty now! I want to go threadless because my HS is shot, I have an unused aheadset, and trying to find a shop that can cut threads into forks might be more aggravation than its worth. I'm not concerned about the threads cutting in because I'll use a shim and use 1 1/8" stems. My major concern is that the steerer might crack or break off, but having googled this to death, I see a lot of warnings that it COULD happen but never any cases where it DID. We'll see . . .

    ps. as a general rule though, I am cheap and lazy.

  6. #6
    all hail der Fuhrer Bush
    Reputation:
    Join Date
    Mar 2004
    Posts
    1,635

    I would not do that

    Quote Originally Posted by jts628
    Oddly enough, I already have one of those on the Bonty now! I want to go threadless because my HS is shot, I have an unused aheadset, and trying to find a shop that can cut threads into forks might be more aggravation than its worth. I'm not concerned about the threads cutting in because I'll use a shim and use 1 1/8" stems. My major concern is that the steerer might crack or break off, but having googled this to death, I see a lot of warnings that it COULD happen but never any cases where it DID. We'll see . . .

    ps. as a general rule though, I am cheap and lazy.
    I have never personally seen broken steerer threads caused by clamping on a threadless stem, probably because most everybody knows better than to do that. I have seen a number of threaded steerers that broke at the threads because quill stems were run too high in them, with the wedge exerting force against the threaded section. I would strongly advise you NOT to do what you propose. Cut threads are a major stress riser just waiting for some force to be inputted on them over time by a nice long lever like a clampon stem. Anyone with any knowledge of metal fatigue and stress risers will tell you it's a bad idea.
    When you say your headset is shot, what's shot? Is it pitted so it indexes instead of turning smoothly? If so, you can just replace the lower race and likely be good to go again, upper races seldom wear out. Or, if it's pitted/indexed, try this in the lower race if you don't have a new lower race: Remove the bearing retaining and replace it with loose balls, a couple few more will fit in without the retainer, stick them in one by one after greasing the lower cup. Then the indexes will no longer line up with the balls because now there's more balls, and the indexing will be diminished or gone entirely. That's how we all kept our pitted Campy Record headsets going back in the day..

  7. #7
    mtbr member
    Reputation: RickD.'s Avatar
    Join Date
    Apr 2004
    Posts
    516
    I have a Tange Switchblade fork that I pulled off my Ibis SS with both a threaded steerer and a threadless steerer. The threaded steer is 175mm long, with 65mm of thread. The threadless steerer is rougthly 220mm.
    Two things to be aware of is that the steerer legnths are for the ENTIRE steerer, including the portion that sits in the crown. Second, and most importantly, both steerers are slightly bent. Nothing horrendous, but it is obvious when they are rolled on a flat surface. Anyone interested in these, drop me a line and make me an offer. I'm not sure how to post pics, so email me and I'll gladly send you some. Thanks.
    Rick
    hlucn_8@hotmail.com

Similar Threads

  1. Just put a Maverick fork on my Bullit
    By mtbbiker in forum Maverick
    Replies: 5
    Last Post: 06-05-2004, 06:18 PM
  2. Replies: 5
    Last Post: 04-14-2004, 08:19 AM
  3. Cannondale Lefty Max+ compared to TALAS :my $.02
    By dawgcatching in forum Shocks and Suspension
    Replies: 5
    Last Post: 04-13-2004, 10:39 PM
  4. rigid fork question: Alu, steel, carbon...
    By jh_on_the_cape in forum Singlespeed
    Replies: 5
    Last Post: 03-24-2004, 04:18 PM
  5. Looking for a one-inch threaded fork w/ disc mounts
    By KavuBiker in forum Singlespeed
    Replies: 9
    Last Post: 03-23-2004, 06:03 PM

Posting Permissions

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