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How Many Types of Bike Seatpost Clamp Are There? | Know Your Bike Better

bike saddle clamp types
Written by Cobie Brown

Saddle clamps are used to attach the seat of your bike to the frame according to your preferred height. Despite not getting much appreciation or attention, this tiny device allows the seat to be secured and flexible for the rider.

Seatpost clamps come in different diameters and are measured in millimeters. That means it’s really important to measure the internal and external diameters of the seat tube. The most commonly used saddle clamps are 27.2, 28.6mm, 31.8 mm, and 34.9mm.

Different saddle clamp types you should be familiar with

Quick release

This type uses a quick-release lever to establish a secure grip on the seat tube. The lever is also accompanied by an adjustment bolt for better grip. Using this type of saddle clamp is the easiest to install as you won’t need any kind of tool.

How to Quick release bike saddle clamps

If you need to adjust the position of your saddle frequently, this is the perfect saddle clamp type for you. However, pay special attention to the durability and flexibility of your saddle clamp. If the clamp isn’t flexible enough, it’ll break and damage your bike.

Bolt-on

They use bolts instead of a lever for better performance but the installation process is more complicated and you’ll most probably need to carry repair tools with you always.

Bolt-on

They offer more security and stability than their quick-release counterparts. No matter which type you end up choosing for your bike, seatpost clamps cost between $10-$40, depending on the brand.

There are two primary types of bolt-on saddle clamps:

Single bolt saddle clamp

A single bolt is used to secure the position. The single-bolt saddle clamp is the most common type of bolt-on saddle clamp. They offer security and a minimalistic, clean outlook.

Double bolt saddle clamp

These bike saddle clamp types use two bolts to establish a stronger grip on the seat post. One bolt is used to squeeze the Seatpost while the other grabs the frame. This allows finer adjustments but makes the bike a little heavier.

Quick release vs bolt-on: Which clamp to choose?

The greatest advantage of a quick-release saddle clamp is its efficiency. You can tighten and loosen the clamp without using any kind of tool. If you are one of those bikes who share their ride or change the Seatpost frequently, this type is perfect for you.

However, there are ways to go around. If you can manage to take the seatpost off whenever you stop, it’ll make it harder for potential thieves to take and ride your bike away. With this type of saddle clamps, your bike will become more flexible and convenient for you.

However, it comes with a set of disadvantages as well. This might be true that the strength of this type of clamp is also one of their weaknesses. They are so convenient that anyone can loosen the lever.

They also add a little weight to the overall setup. The lever is prone to wear and tear; and may require replacement sooner than you expect.

On the other hand, if you are okay with your seatpost’s position being fixed, bolt-on saddle clamps will be a better choice for you. Instead of a lever, the seatpost will be secured by a bolt.

Although anybody with an Allan key can loosen your bolt, they are comparatively more secure than a lever. You can also opt-in for double bolt saddle clamps if you want better protection. Double-bolt clamps are heavier and more expensive, but not as much as the lever-action ones.

Another disadvantage is that you’ll probably need to carry an Allan key with yourself at all times. However, as bolt-on clamps are cheaper, they are also the most widely used types.

If you need to adjust the Seatpost frequently, choose a quick-release saddle clamp. And if you are into a cheaper and more secure alternative, go for the bolt-on type.

How to replace a seat clamp: Step-by-step

The installation is quite straightforward. All you’ll need is a digital caliper, a seat post gauge (optional), a paper towel, some grease, and an Allen key/wrenches. Here’s the step-by-step process:

Step 1: If you are using a quick-release lever, open the lever and loosen the adjustment nut. The clamp will loosen up, and you’ll be able to remove the seat post.

Step 2: In the case of an Allan key-based clamp, use the key to loosen the clamp and then remove it.

Step 3: Take a piece of paper towel or damp cloth and clean the inside thoroughly, otherwise you won’t get accurate measurements.

Step 4: Take a digital caliper and measure the inner and outer dimensions of the seat tube. Use a seatpost gauge if you can get your hands on one. They’ll provide more accurate readings.

Step 5: Take multiple measurements, each one should be 90 degrees apart from the other.

Step 6: Once you’ve got the measurements, look for a suitable size clamp.

Step 7: Saddle clamps come in increments of 0.2 mm, so adjust that length when looking for the perfect saddle clamp for you.

If you prefer video tutorials, here’s the process super-simplified:

Step 8: Once you have your seat clamps, you’ll notice the clamp is one way. Insert the clamp into the bike’s frame through the open side. Make sure that the seat post is at least 8 cm inside the bike’s frame.

Step 9: If you have to force the seat post in, it’s too tight and will break easily. On the other hand, if the seat post enters the frame without any external force, it’s too loose. The right size seat post will take minimal effort to sit in place.

Step 10: Once you are certain about your choice, apply some grease on the lower end of the seat post and insert it again.

Step 11: Lastly, tighten the seat clamp in place using the lever or an Allen key. If you are using a lever, pay special attention to how much pressure it is taking to lock the clamp. Use the adjustment knob to tighten the clamp.

If you keep the knob loose, the seat post will move and can crack at any time. On the other hand, if the knob is too tight, you won’t even be able to close the lever. That’s why it’s important to find the perfect point where the clamp will tightly grip the seat post.

Additionally, make sure that the clamp’s opening lines up with the dedicated slot in the frame. In case you have an older bike, the clamp might be integrated into the bike’s frame. If that’s the case, you will still be able to replace the bolt/lever of the clamps.

About the author

Cobie Brown

Born and grew up in Colorado, I chose to work in the field of what I liked most, biking. I’ve been working as a full time mechanic in the cycling industry for over 13 years. I started BMXing when I was just a 6-year-old kid and got hooked from the very first day. Then I started riding and not a single day went by since then that I didn’t touch my bike.

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