Rear wheel spoke tension general question

jgsi
jgsi Posts: 5,062
edited December 2016 in Workshop
Any reason for spoke tension to be higher on driveside as opposed to non ds (rear wheel)?

Comments

  • keezx
    keezx Posts: 1,322
    Yes, there is a reason.
  • jgsi
    jgsi Posts: 5,062
    good
  • jgsi
    jgsi Posts: 5,062
    Chapter 5 of me Blue Book has explained it all... must actually read more of it over winter
  • Nick Payne
    Nick Payne Posts: 288
    Yes - on a normal bike frame the left and right dropouts are equidistant from the centreline of the bike, and because the drive side hub flange is closer to the centreline of the bike than the non-drive side (in order to accommodate the cassette cogs), the spoke tension on the drive side needs to be higher to keep the rim centred in the bike frame.

    A couple of ways to minimise the tension difference are a) use a rear rim with the spoke holes offset to the non-drive side, to increase the bracing angle of the drive side spokes (have a close look at a Dura-Ace C24 rear wheel next time you see one), or b) use a spoking pattern such as Campagnolo use on their wheels, where there are twice as many drive side spokes as non-drive side spokes.

    Tandems generally use either 145mm or 160mm rear spacing, and because of the wider spacing can have both hub flanges equidistant from the centreline and therefore have equal spoke tension left and right.

    Fatbikes such as the Surly Pugsley have the drive side dropout offset further from the centreline of the bike than the non-drive side dropout (needed so that the chain can clear the fat tyre in all gears) - this has the secondary effect of reducing the difference in spoke tension between the two sides.
  • jgsi
    jgsi Posts: 5,062
    Good answer . gets a rating ;-)
    I only asked because I had to replace a spoke this week.

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