How to stop your seatpost from slipping

Carbon fibre frames and seatposts tend to slip over time, but there are things we can do to prevent it

Clock20:35, Monday 4th December 2023

Carbon fibre seatposts are susceptible to slipping inside your frame, because the smooth finish on the post does not always allow for enough friction to be generated in the clamping process to hold it tightly enough. Luckily there are a few things that can be done to get even the slippiest of seat posts firmly set in position.

Making sure your seatpost is clamped firmly will protect your seatpost from scratches, as well as most importantly retaining your correct riding position. Sometimes carbon seatposts will slip all of a sudden and will immediately be noticeable. Other times it can be a very slow and gradual change that can be hard to notice until you start to suffer discomfort.

After spending time and money on a bike fit it is worth making sure that you are riding in that position, so here are our top tips for stopping your carbon fibre seatpost from slipping.

Tools Needed

Be careful when removing your seatpost so to both not damage the post or any cables that might be connected

Step 1

Remove the seatpost

The first thing to do is remove the seatpost, making sure you have fully backed off any clamps that hold your seatpost in place first. If you have electronic shifting you need to be careful when fully removing the seatpost as this is where the battery is sometimes housed. When the post is fully removed, make sure to carefully disconnect the battery before moving it away from the bike.

Top Tip

For bikes with integrated clamps, be careful when you fully remove the seatpost as the clamp mechanism can fall down the seat tube and will need to be carefully extracted and refitted.

Removing any grease or contamination will make sure that the carbon paste increases the friction between the seatpost and the frame

Step 2

Clean the post and seat tube

Now that the seatpost has been removed it is time to clean both the seatpost and the seat tube. The main thing you want to make sure of is that all grease or dirt is removed from the area. Using isopropyl alcohol or disc brake cleaner can help get rid of all the old grease.

Now that the post is removed it is time to check for any damage to it

Step 3

Visually assess the post for damage

Now is the perfect time to inspect the seatpost for any signs of damage. If you have over-torqued the clamp on as carbon seatpost in an attempt to get it to grip better there is the chance it could have crushed the seatpost. When looking for any scratches or signs of crushing, if you come across anything you are unsure of take it to your local bike shop for them to inspect and give their verdict.

Top Tip

Some seatposts do have a section of rougher textured carbon that is aimed at increasing the friction between the post and the frame.

Cleaning and greasing the clamp will make sure everything is in good working order

Step 4

Clean the clamping mechanism

As with every bolt on your bike, the seatpost clamping bolt will have a specified torque setting. It is important to make sure that the torque you apply goes to the clamp rather than as friction in the threads. Cleaning the bolt threads will make sure that the clamp operates properly and all the force applied goes into clamping the seatpost. Once the clamp bolt is clean, apply a small amount of grease to the threads and refit it.

Cover the section of post that will sit inside the frame with a thin layer of carbon paste

Step 5

Apply the carbon paste

Now that everything is clean it is time to apply a thin layer of carbon paste to the section of the seatpost that will sit within the frame. With the carbon paste applied, it is time to refit the seat post, making sure not to trap any cables as you do so. When the seatpost has been inserted to roughly the right height, wipe off any excess paste with a rag.

Setting your saddle height might take some time if you don't have your measurements to hand

Step 6

Set the saddle height

If you know your bike fit measurements this part will be relatively pain-free. For those of you who do not know your saddle height measurement this will take a little more time. Fear not, however, as we have you covered with a how-to on saddle height.

Clamping the seatpost with a torque wrench is recommended

Step 7

Clamp the seatpost

Now that the saddle has been set to the correct height it is time to clamp it in place. To nip the clamp up so that the seatpost stays in place a simple hex key can be used. When you start applying tension on the clamp you will want to swap over to a torque wrench to ensure that you do not exceed the specified torque value.

Top Tip

If you can't see a torque value on the frame or clamp, head over to the manufacturer's website where you can find user manuals based on the bike model and year.

If the post still slips it is time for further investigation and potentially a trip to your local bike shop

Step 8

If the issue continues to persist

For almost all cases following, the guidance above will remedy the issue of a slipping seatpost. If you find that even after carrying out the tips above that your post still slips on the frame, it is time to dig a bit deeper into what could be causing it.

Checking that the clamp isn’t bottoming out is the easiest place to start before looking closer at the frame or post for any cracks. If you are struggling to pinpoint what could be causing the issue, popping the bike down to your local bike shop would be the recommended course of action.

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