5

I have a Trek 7500FX with Bontrager race lite 700x32 tires. I have broken spokes, I no longer have the book what size spokes do I need?

enter image description here

Móż
  • 23,532
  • 3
  • 71
  • 120
Tee
  • 51
  • 2

1 Answers1

6

"The correct length" can be found by measuring an existing spoke. If your broken spokes have failed at the hub, simply measure from the thread end to the inside of elbow/turn and buy that measurement. Otherwise take off a known-good spoke, measure, and reinstall.

I've occasionally had to shorten spokes by 1-3 mm because they poke through the nipple into the tube. 10 seconds with a dremel or a couple of minutes with a hand file are all it takes. Whereas you can't lengthen a spoke, so if in doubt go for a 1mm longer spoke.

Depending on how many spokes have broken, you might find the adjacent surviving spokes are overtensioned now, so get a couple spares, and a decent spoke tool if you don't already have one.

EDIT: Moz makes an excellent point if your wheel is a low spoke count (like in the picture) If you're not feeling confident, it may be safer to take the wheel to a shop for spoke replacement and true and tension check.

Criggie
  • 124,066
  • 14
  • 180
  • 423
  • 4
    I assume that the OP has a spoke tool and tensiometer. Replacing spokes in a low spoke count wheel is not for the under-equipped, and with V brakes and wide spoke spacing like that it's not for the faint-hearted either. – Móż Apr 04 '16 at 00:13
  • 1
    Agreed, but someone who has the tools and knows how to use them likely knows how to measure a spoke for length too. They're not likely to refer to the manual/book. – Criggie Apr 04 '16 at 01:27
  • 2
    Your advice on how to measure broken spoke is good one, but it could be read in wrong way when measuring unbroken one. So to clarify it, unbroken spoke is measured from the inside of the elbow to the very end of the threads. – Davorin Ruševljan Apr 04 '16 at 07:55
  • 1
    @DavorinRuševljan Edited - thank you for that. You have enough reputation to edit other people's answers, so don't be shy about making the answers better. Trick is to leave the meaning as-is and only correct minor things (like this) and to avoid changing the meaning or intent of the answer. – Criggie Apr 05 '16 at 08:27