Viewing 12 posts - 1 through 12 (of 12 total)
  • wheel rim tuning question for wheel builders / amateur home mechanics / bodgers.
  • doncorleoni
    Free Member

    Hi all, when centering a dished wheel rim is it preferable to:

    1) increase tension brake disc side (thus increasing overall tension)
    2) Lower tension non disc side (thus lowering overall tension)
    3) combination of both

    need to shift a disc wheel over by 2-3 mm and usually go for option 3 but sometimes that is tricky to do if you need less than 1/4 turns of the key (rim ends up too far over!).

    There is obviously a limit relating to the max tension the rim will allow But is it generally best to aim for higher tension (1) or lower (2).

    Old school caliper rims not an issue as I aim for equal tension on both sides but obviously dished rims require higher spoke tension on one side.

    MaryHinge
    Free Member

    I’ve built a few wheels, but I’m a DIYer.

    I try to get tension pretty even both sides.

    On rears it is accepted that you can have less tension on the non drive side, which would be the disc side. But I still prefer to try to get them pretty even.

    Not had any problems with the 8 or so wheels I’ve built, one pair of which is currently being battered around the Dyfi by a 19 stone Clydesdale!

    scaredypants
    Full Member

    well, depends, obvz

    if the overall tension’s already high, you’ll need to either go for 2 or 3
    if not fully tensioned, then 1

    doncorleoni
    Free Member

    yup 🙂 I guess i should invest in a spoke tension tool as opposed to a guitar tuner (which does work surprisingly well).

    I guess what i am asking lets say i am well within limits either way on tension – is it better to go for more tension or less or does it make no darn difference (i am guessing the latter).

    ta

    scaredypants
    Full Member

    if you’re “well within limits”, then go tighter

    IMO

    IANAWheelGuru

    doncorleoni
    Free Member

    well i think i am “within limits” ….I know that i build my drive side spokes (front) to a G# pitch which feels about right (and is optimal for a spoke length of 275 ish mm according to Mr Sheldon Brown).

    No idea what tension this relates to but feels (and sounds the same as my factory built hope hoops)…. but all my wheels I have had a go at building have taken lots of abuse and seem fine 🙂

    probably massively over thinking this as usual. I doubt 1/2 turn on one side is going to make much difference at all!

    thanks

    nemesis
    Free Member

    I would always go tighter rather than looser but if the tensions are already about right I would both tighten and loosed respective sides to get the dish right.

    Bez
    Full Member

    If you need to move it because it’s gone out of true, add tension, because clearly it can’t have been tightening itself while you’ve been riding.

    If you’re building from new it depends where you’ve got to. But I tend to err on the side of higher tension. I’ve have failures from under-tensioned wheels (which I haven’t built) but never (yet) from one I’ve built with higher tension.

    I try to get tension pretty even both sides. On rears it is accepted that you can have less tension on the non drive side, which would be the disc side. But I still prefer to try to get them pretty even.

    That’s simply not possible (unless you don’t want your wheels to be in line with the bike and each other). The ratio of total spoke tension—and thus individual spoke tension if you have a normal wheel with the same number of spokes each side—between the two sides is defined entirely by the angles of the spokes on those sides. Trying to get those tensions “pretty even” is like trying to balance a 30cm ruler with “pretty much the same” weight on each end when it’s supported at the 10cm point.

    forzafkawi
    Free Member

    Bez – Member

    If you need to move it because it’s gone out of true, add tension, because clearly it can’t have been tightening itself while you’ve been riding.

    If you’re building from new it depends where you’ve got to. But I tend to err on the side of higher tension. I’ve have failures from under-tensioned wheels (which I haven’t built) but never (yet) from one I’ve built with higher tension.

    I try to get tension pretty even both sides. On rears it is accepted that you can have less tension on the non drive side, which would be the disc side. But I still prefer to try to get them pretty even.

    That’s simply not possible (unless you don’t want your wheels to be in line with the bike and each other). The ratio of total spoke tension—and thus individual spoke tension if you have a normal wheel with the same number of spokes each side—between the two sides is defined entirely by the angles of the spokes on those sides. Trying to get those tensions “pretty even” is like trying to balance a 30cm ruler with “pretty much the same” weight on each end when it’s supported at the 10cm point.

    I agree.

    I use a tension meter and tend to bring the drive side tension incrementally up to max and then handle the final dish by increasing the tension incrementally on the non-drive (disc) side. I think this method was advocated by either Gerd Schraner or Jobst Brandt as it results in a slightly higher NDS tension which will tend to be lower than the DS for reasons expressed by Bez above.

    Bez
    Full Member

    I use a tension meter and tend to bring the drive side tension incrementally up to max and then handle the final dish by increasing the tension incrementally on the non-drive (disc) side.

    If you’re doing that then your drive side tension will be higher than you want it (assuming that’s what you mean by “max”): once you’ve got the wheel tensioned, adding tension to one side will also add tension to the other. Again, it’ll be added in that same ratio defined by the angles of the spokes.

    Remember that at any given point in time, the sum of the forces pulling the rim towards the drive side must be the same as those pulling it towards the non-drive side, otherwise it would start accelerating in one direction or the other…

    orangeboy
    Free Member

    I also tend to tension the drive side rear or left front for a disc wheel first then use the slack side for dish but do keep an eye on the right side as is easy to go to high.

    To much tension is a bad thing

    bigjim
    Full Member

    Bez is on the money

    I hate very slack spokes on the nds. If you are already a bit on the slack side and you aren’t using any kind of thread locky stuff then I think you’ll be at higher risk of spokes slackening off completely from things like big vertical hits to the rim like hitting a water bar or root bending the rim inwards momentarily.

    I’m very keen to build up a Boost wheel or something like the american classics with less dish.

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