Spoke length woes

munkster
munkster Posts: 819
edited February 2017 in Workshop
[edit]Save yourself some time by not reading the rest of this, and just checking the lengths of spokes when you receive them. I've learned this lesson so you don't have to... You're welcome :shock: :D [/edit]

Getting round to building up a Kinlin XR22T asymmetric rear rim (thanks Malcolm) with Hope Mono RS rear (130mm width) and the NDS spokes are coming up short.

Hope (http://www.hopetech.com/wp-content/uplo ... CD-v21.pdf) says the hub has 47mm/54mm PCD and 34.5mm/16.5mm offset.

ERD 596mm, offset 3mm.

This seems to give me NDS 294mm (rounded up slightly), DS 292mm (rounded down slightly) using the Wheelpro calc, and I corroborated it with another site as well as repeating it just now afresh.

I'm doing 28H 3x - anyone got the feintest scooby doo what is going on here? Am i doing too many crosses? Have I made a total mess of the calcs? The flanges are quite big and am wondering if I should've gone 2x - they look quite tangential and sort of nearly lie over the adjacent spoke heads. Maybe that's causing the shortening? Either way I can barely nip up the nips, they are almost going tight without any effort.

Hope someone has an idea! Cheers.

Comments

  • The Rookie
    The Rookie Posts: 27,812
    Have you checked the measurements of the flanges?

    Did you measure the ERD, NEVER trust it they are always wrong.

    2mm difference in spoke length with a 3.5mm difference in PCDs sounds suspicious.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • munkster
    munkster Posts: 819
    edited February 2017
    I've just removed one of the NDS spokes and found that they are the wrong length, despite the packing slip being "correct", so silly me for assuming they would send me the right ones I guess... I'd ordered Lasers for the front and NDS and they've just sent the same length for both.

    At least I'm not going mad. For a change. This wheel won't be getting built this weekend though, the spokes came from Germany :-(

    Oh and Mr Rookie, they are asymmetric rims so presume that the lengths are closer than usual due to this. Also ERD supplied by Malcom @ Cycle Clinic and measured by him, and which differs from the manufacturer's number by 1mm...
  • ugo.santalucia
    ugo.santalucia Posts: 28,312
    Get DT 14 mm nipples... occasionally it did happen, always sorted it with longer DT nipples, never had any problem with that
    left the forum March 2023

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