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  1. #1
    Old school BMXer
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    What's the head angle on your tandem?

    Anybody ever actually measured the head angle on their 26" tandem? I'm not interested in claimed specs, I want to know what people are really running.

    The head angle on the tandem that I'm building came out a little slacker than what I was shooting for. It's about 68 degrees with 120 mm fork, unloaded. I don't want to run it much shorter, because I want the boom tube just above level when loaded. I can turn the Fox TALAS fork up to 160, but I'd prefer not to.

    I've seen a few ECDMs running around with fairly long Marzocchi forks (66?), and the head angle looks really slack, even when loaded.
    May the air be filled with tires!

  2. #2
    Long Live Long Rides
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    I tried to measure mine once, but the instrument I used was a POS, so I didn't trust the results. Remember that on the tandem with a longer wheel base, the change in HA due to fork length is reduced by about 1/2. We run a Jr.T with 170mm on our Ventana and have no issues. I'll try to get a better HA measure.

  3. #3
    Professional Crastinator
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    It's hard to get a good measurement.

    I don't know if this really applies to your question since we're rigid and all, but...
    Quote Originally Posted by Fleas
    '98 MT1000 w/ Instigator fork and 2.3" Nevegal tire:

    HTA = 71.7* by digital level
    ATC = ~17.75 by a tape measure (Surly says 447mm = 17.59")

    I can't imagine what the HTA was with the orig. fork - no wonder it was so twitchy.
    Hope that helps.

    -F


    Handling is good. I would even say great. I don't know that I'd want it slacker. We tried it with a 29" front wheel... was not good.

    -F

  4. #4
    Old school BMXer
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    Thanks guys.

    On single bikes, I like slack. My 29er hardtail has a 67.5 degree head angle with the fork set at 120 mm and 68.5 when set at 95 mm. My 26" suspension bikes vary from 64 degrees to 67.5 degrees. But alas, these are single, and I really don't know what to expect with slack on a tandem. I'm afraid it's going to push a bit. But I'm at the point of no return with the head angle, so I'm curious of what others actually run.

    By the way, those cheap weighted angle finders are generally pretty good within a degree. If you have an iPhone, there's even an app for that to use it as an angle finder.
    May the air be filled with tires!

  5. #5
    mtbr member
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    Something approaching 67.5 (measured with my Mk. I eyeball, string, and a very tiny protractor).

    ECdM - 17/16
    Marz 66SL 160mm fork

    That is with no load. Sag is ~3/4-1", and I can't measure head angle when I'm also providing the sag

    The ECdM is rated at 72 with 100mm fork.

  6. #6
    PMK
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    I will try and measure our ECDM with the clipped Fox fork. Just need to fix the digital protractor wires first...

    FWIW, I know this is about headtube angles, the thing is so much more happens when these angles or even a different fork is installed.

    The big thing is the change in trail dimension. The angle plus fork offset provide the mechanics of how much effort it takes to turn or pull the bars back to center, and also probably more important is how much side grip the tire may see from the contact patch with the ground.

    PK

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