Replacing the rails on a Brooks Flyer saddle

A couple of weeks ago I rode through a pothole on my bike, there was a loud bang and I was suddenly a lot closer to the pedals.  The rails on my beloved Brooks Flyer saddle had cracked!

On closer inspection the rails were bent as well as cracked, just in front of where the seat post clamp was positioned.  Googling found plenty of examples of this happening to Brooks rails but mostly with the saddle all the way back on the rails rather than all the way forward (which puts the rider weight more directly over the seat post).  Given the cost of the saddle, I wanted to try and repair it.  I purchased replacement rails and today settled down to repair my saddle.

What you need:

  • The “Flyer bracket and coil assembly” (BYB299) which I got from SJS Cycles.  You can purchase direct form Brooks but I found that shipping was cheaper, especially as I was ordering other things from SJS anyway.  It might be possible to order the rails separately and reuse your existing springs but I thought I may as well replace the whole lot.  If you buy just the rails, the instructions below will still work but you will need to undo the nuts that hold the rails to the springs rather than the springs to the saddle.
  • A 1/2″ spanner
  • A Brooks tension spanner
  • Some time to do the job.  This took me about  45 minutes with a few interruptions so it can probably be done in under 30 minutes.
Parts and tools
Parts and tools

To replace the rails:

  1. Remove the saddle from the bike.  This is obvious, I know, but you may wish to mark the seat post bracket position for tilt with a marker so you can put the saddle back in the correct position easily.  Work on the saddle upside down.
  2. Loosen the tension pin fully.  I am not sure if this is 100% necessary but it looked like it was and seemed to make the later steps easier.  Take note of how much tension is in the saddle before releasing it so that it can be re-tensioned afterwards.

    Nose of the saddle
    Nose of the saddle
  3. Using a 1/2″ spanner undo the nuts where the the coils join the saddle.  The nuts are hard to get at and required some creative angles with the spanner.
  4. Once the nuts are removed, lift up the bracket and coil assembly and flip it 180 degrees so that it is nose-to-nose with the saddle.

    Removing the old rails
    Removing the old rails
  5. Lift the bracket and coil assembly, tension pin and tension shackle out of the saddle.  Keep them all together.

    Tension pin and shackle
    Tension pin and shackle
  6. Place the replacement assembly next to the old one and move the tension pin and tension shackle across to the new assembly.  Make sure that the pin and shackle are in the same position on the new assembly.
  7. Replace the new assembly, tension pin and tension shackle nose-to-nose with the saddle and flip it into the saddle, slotting the coils onto the bolts.
  8. Replace the nuts on the bolts and tighten them.  Again, this requires creative use of the spanner.  It is nearly impossible to avoid scratching the coils with the spanner (at least with mine) but try to avoid it.  The bolts should be tight but not too tight or they will start to dig into the coating on the coils.
  9. Re-tension the saddle to the tension as above.  My saddle seemed a little under tension after this step so I added a little more.  It is possible that that was a contributing factor in the breakage to begin with.
  10. Replace the saddle on the seat post in the correct position.
  11. Go for a ride and check everything feels OK.
  12. After a few rides, check that the bolts are not loosening.

Disclaimer: I am just a home bike tinkerer and not a qualified bike mechanic.  Use these instructions at your own risk.

More shots of the cracked rails.  They should be straight between the bend in front of the coils and the bend up to the nose.

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