How to cut your Ribble seatpost safely

When we build our bikes, we set the seatpost length to suit the frame size, with some adjustment up or down. But because every rider’s fit is different, sometimes the seatpost needs shortening.

We don’t cut seatposts in-house because once trimmed, the material can’t be added back. You’ll only know the exact length you need once you’ve set your ideal saddle height.

Good to know

• Cutting a carbon seatpost is perfectly safe if done correctly

• It won’t void your warranty when carried out properly

• If you’re not comfortable doing it yourself, any good local bike shop will be able to help

How to cut a carbon seatpost

What you’ll need

• Fine-tooth hacksaw (ideally with a carbon fibre-specific blade)

• Vice or clamp (with a cloth to protect the post)

• Electrical tape

• File or sandpaper

• Protective gear: dust mask, gloves, eye protection

• (Optional) Carbon paste

Step-by-step guide

1. Remove the seatpost – Loosen the clamp and take it out. Remove any internal cables or a Di2 battery first.

2. Mark your cut – Clean the post and wrap electrical tape around it at the cut point to create a guide.

3. Secure safely – Wrap a cloth around the post and fix it in a vice or clamp.

4. Cut carefully – Using your hacksaw, cut slowly along the tape line while wearing protective gear.

5. Smooth the edge – Use sandpaper or a file to tidy the cut.

6. Clean up – Remove tape, wipe away dust.

7. Reinstall – Apply carbon paste if required, then refit the post, reconnect cables/battery, and set saddle height.

Important

• Always maintain a minimum insertion depth of 100mm for safety.

• After cutting, the original “Minimum Insert” marking won’t be accurate — check carefully before riding.

Aero seatposts – extra guidance

If you’re trimming an aero seatpost, it must have a 45-degree chamfer cut on the trailing edge.

Steps:

• Insert depth must be between 6.5cm (minimum) and 8.5cm (maximum)

• Mark your cut with a grease pencil

• After trimming, apply a 45-degree chamfer to the trailing edge to keep the correct fit and function

With these steps, your seatpost will be perfectly fitted — giving you a safe, comfortable ride.