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  1. #1
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    1999 gt lts 2000-want to ad disc brakes or get new frame

    this is for a friend.we both purchased out frames in highschool to this day his looks brand new.his main complaint is not having disc brakes.for his birthday im going to do 1 of 2 things.buy all need parts to add disc brakes to the rear or get him a new frame.
    does ANYONE have a connection or know of a way to ad rear mounts correctly?if that just wont work,what companys make a frame close the setup GT used so hes still happy?

  2. #2
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  3. #3
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    My 2 cents

    There are a few threads on the topic, and no, I wonít get smart this time

    Braketherapy is a good design, but Iíd hesitate to use that because it applies a significant rotational force (twist) on inside of the left seat stay (note brake boss is welded asymmetrically, inward), that I have seen boss being ripped out of the seat stay. Canti/vee were deigned to work in symmetrical way, pushing seat stays out equally cancelling out the rotational forces. In my humble opinion, applying such a force on just one stay is asking for trouble.

    I personally use A2Z adopter (ebay) mentioned in many threads here on my 93 Zaskar. Itís probably no better than Brakethreapy, but my rationale in using this are:
    1. It clamps a dropout, applying rotational force where it is supposed to be applied, in the direction it is supposed to be applied. So no undersigned ďtwistĒ if you will.
    2. GT, over wide range, used a flat, beefy square dropouts. A2Z fits best on such design very well, while it wonít work on older, steel forged (artistic I may add) dropouts.
    3. Cheap. Braketherapy requires (as far as their instructions go) their proprietary hubs. I already had spare disk wheels, so $30 was all it took.
    4. Light Ė Itís got to be lighter than BTÖ


    That all said (here we go, Iíll contradict to myself here), I would not put the disk on the frame it I werenít having an emotional attachment to the frame. I do, with old Zaskar, so I went this route. As I have no experience on i-drive frame, I canít say for sure, but adding disk on full suspension frame may cause some unwanted bob during braking, especially if the frame isnít designed to optimize in that situation. This isnít an issue with hard tail.

    My two cents here.

    Nice to meet you again, Chirosangaku san, if you are Chiro-san.

  4. #4
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    Quote Originally Posted by hatake
    My two cents here.

    Nice to meet you again, Chirosangaku san, if you are Chiro-san.
    OMG, I am two cents richer now!
    And now I remember there is A to Z as well (and I do have one)

    Probably an A to Z is a better choice considering the price is significantly lower.
    And my GT LOBO kit from brake therapy do weigh quite a bit.

    Hats off to hatake-san.

  5. #5
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    I just bought an A2Z DM-UNI brake adapter for my frame I am emotionally attached to (2000 Aggressor). I'll be installing it next week if my wheels come in time.

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    Braketherapy type

    Found it:
    Attached Thumbnails Attached Thumbnails 1999 gt lts 2000-want to ad disc brakes or get new frame-seatstaybrakeadopterdisaster.jpg  


  7. #7
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    is not the i-drive.i predates that setup.he just happens to love the bike and cant afford a new ride.i like the one you suggestd and i placed and order already.with the money saved i scored a pair of stroker trail takeoffs.he gets my rydes and i get the trails.thanks for the help

  8. #8
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    Man I hope that doesn't happen to my frame.

    Last year I saw the brake therapy design and decided to copy parts of it for my 95 Zaskar Le
    I designed the caliper mount a little differently but made the brace up to the brake boss the same. To make matters worse I made it so I can use a 185mm rotor. This will be the second summer on this set up.

    Now I just made the same setup for my 99 XCR-4000. Now I'm worried.

  9. #9
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    Quote Originally Posted by jamiespg
    .....
    I designed the caliper mount a little differently but made the brace up to the brake boss the same.....

    Now I just made the same setup for my 99 XCR-4000. Now I'm worried.
    I'd like to see that on the XCR.

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    Here's a couple of photos of my possible mistake. The only thing i think might save mine over the brake therapy setup is that this is clamped under the quick release so that might spread some of the load. I think with the brake therapy setup floats on the hub.
    Attached Thumbnails Attached Thumbnails 1999 gt lts 2000-want to ad disc brakes or get new frame-dsc00825.jpg  

    1999 gt lts 2000-want to ad disc brakes or get new frame-dsc00826.jpg  


  11. #11
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    The friction between the quick release and the mount is negligible in resisting the twisting forces from the caliper. I'd try to fabricate a piece from the rear ball joint down to right above the weld of the seat stay to the dropout. I would have suggested a brake bridge bolted to the top of the seat stay by the shock mount but there are no holes there.

    Your adapter does look slick and the polished XCR frame is cool too. Where did you get the parts? Fabricate everything yourself?

  12. #12
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    I work at a Street rod shop and we have a couple of mills and a lathe. I'm going to check out what you suggested. I'm not too worried about it on the idrive frame because if it breaks ill get a new rear triangle, more worried about the zaskar le I have the same setup on.

  13. #13
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    I'd remove the stud and put the upper joint right on the aluminum. That stud is a lever arm on that weld. Make that bridge, or extension, that rests on the lower seat stay from the bracket. You can then split the load between the two if the rod is adjusted correctly. The one I made several years ago used the rod design and it caused a side load on braking that screwed up my brake alignment.

  14. #14
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    Quote Originally Posted by nation1979
    this is for a friend.we both purchased out frames in highschool to this day his looks brand new.his main complaint is not having disc brakes.for his birthday im going to do 1 of 2 things.buy all need parts to add disc brakes to the rear or get him a new frame.
    does ANYONE have a connection or know of a way to ad rear mounts correctly?if that just wont work,what companys make a frame close the setup GT used so hes still happy?
    Have you a picture of the rear chainstay?? GT made two different chainstays for the LTS. If you have two drillings at the left side you can use the BETD-adapter. It is easiest way. If you have the other model, you can use the A2Z -adapter.

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