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  1. #1
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    off center hub newbie question

    I am bulding my first set of wheels. I recently bought the Marzocchi z150 fork and shimano XT M776 20mm through axle disk hub. I mounted the hub onto the fork to make sure it fits and noticed that the hub seems to be off center by about 5mms. The 110 axle holds the unit perfectly tight so I'm wondering whether the hub is supposed to be off center to accomodate for the disk brake or if there is an adjustment that can be made to center it in the fork. Any input is highly appreciated.

  2. #2
    www.derbyrims.com
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    Quote Originally Posted by kdubovenko
    I am bulding my first set of wheels.

    I'm wondering whether the hub is supposed to be off center to accomodate for the disk brake or if there is an adjustment that can be made to center it in the fork. Any input is highly appreciated.
    Yup, and probably the same length spokes will accommodate both sides. If you don't have a dish tool, you will need to flip the wheel in the truing stand a few times as you tighten the spokes to measure the dish offset so the rim ends up on center in the truing stand (and fork). Use another built wheel as a pattern to lace up the spokes correctly. Also align the hub's brand label to the rim valve hole (not necessary but it's normally done by experienced builders.) Reusing spokes is fine (if they fit). I always use new alloy nipples because the threads corrode and may not hold a tight tension or fail soon. Use any oil to prep the threads, I use a light grease (Slick Honey), there is specific oil generally called spoke prep which is probably better, it helps keep the spokes from winding up when tightening. tension the flatter side of the dish first (the rotor side of the front wheel, drive side of the rear) to be very tight and true the rim's roundness (vs egg shape or squared) on this flatter dish side, then tension the more angled spoke side with will tighten the flatter side even more than you could turn the nipples without stripping. When you've got the wheels nearly fully tensioned and just about perfectly true take the wheel out of the stand and place the hub axle on the floor and lay your hands onto the rim and press your weight onto the rim sideways all the way around the rim and flip to the other side and repeat - this will relax some windup and cross spoke friction, until it stops creaking and pinging. Then tension to true, it will never be absolutely perfect, but try to get within 1/16 inch of true and centered. The rim roundness may be difficult to make perfect, some compromise may be needed, this is where better quality rims such as Mavic and DT Swiss are easier to build being more perfectly round from the factory compared to some cheaper rims.

    This DT Swiss spoke calculator is handy for buying the correct length spokes.
    http://www.dtswiss.com/SpokesCalc/Calculator.aspx

    Building your own wheel will take many hours the first time, but its very rewarding in the end. It gets faster to do each time as you improve your methodology. I think my first wheel took 4 or more hours about 12 years ago. I've probably done at least 12 or 14 of my own wheels and now I'm down to a little over 1 hour per wheel now.

  3. #3
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    thank you derby,

    You're advice was really helpful. I noticed you mentioned mavic rims as an example, I have mavic XM 719s so hopefully theyll make the job easier. thanks again

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