Custom Seatpost Build

Hi everyone. Builder’s like Bingham Built and Groovy make beautiful custom posts and I’m trying to make myself something the same. I was wondering what they call the clamp thingy that holds the seat to the post on a custom seat post?

Are you talking about this kind of seatpost?


I don’t know the exact name, but companies call it the “cradle” or “seat clamp”


Firefly CNC machines a housing to fit this clamp system:

Thomson: Shop Bike Thomson

There is a relevant discussion about seat toppers here: Seatmast Topper Spec & Discussion

IMO the holy grail design would be a weld-on 3D printed titanium seatpost head that is offset (setback) and uses the Thomson hardware. It won’t be cheap though, probably $80 for the seatpost head print.

Its totally possible, Pinarello 3D prints the clamp hardware on their production bikes.


The Thomson hardware project is on my growing list of things to do.


The top picture is what I had in mind. The blue insert clamps the seat and allows it be to rotated. The mast looks simple enough create, I am wondering what the inside of the clamp looks like.


Upon further digging, the Bingham Post is made/branded Kent Eriksen. They sell replacement hardware: Kent Eriksen Seatpost Hardware Replacement Kit | Bingham Built Bikes

An exploded view:


Closeup of the head:

These single-bolt designs concern me. Not saying they don’t work, but I have had some really bad experiences with them slipping. The very clear warning on the clamp page does not inspire confidence:

Don’t tighten these down more than 12nm as they might crack and it’s not needed to go that tight.

That being said, If it does not slip, it is a beautifully elegant design.

Are you looking to make this in steel or titanium? Does anyone have any real world experience with the Enve 2 Bolt hardware?

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The most common view of single bolt seat posts


This joke deserves a gif :clap: :clap: :clap:


Bingham’s Sweetpost is not the same as Kent Eriksen’s. See description of the Sweetpost small parts -

Replacement caps for the Bingham Built Sweetpost. Includes 2 caps only.
These are Not compatible with the Kent Eriksen Sweetpost.

I can confirm this because we make Bingham’s sweetpost clamp parts here at PMW. It is a much more sophisticated design with an inner bolt and 2 outer bolts. The inner bolt cinching the saddle angle, and the outer bolts clamping only the seat rails. It is stunningly simple looking from the outside for how complex it is on the inside. Fabricating one of these yourself would be a huge undertaking.

What @wzrd did with Thomson hardware in the seatmast topper spec & discussion that @Daniel_Y posted above seems to me to be a very cool way to fab your own custom seatpost.


Looking at it from the inside, I can see that will not be easy to reproduce. It does look incredibly simple from the outside.


The thing is a work of art


Thanks for the inside info.

I found this video that explains the seatpost:

Its a really cool design. I was wondering where the 3rd bolt was hidden, but it’s inside! So sneaky!

@TDotBikes if you really like the Bingham design, I don’t think it hurts to reach out and ask if you can buy all the hardware to make your own post. Most builders are very nice and happy to help out.

For example, No22 bikes sells forks as No6 to other builders.


I haven’t made the jump to welding Titanium yet. That’s the next level and my ultimate goal. I’m sure Bingham would help out but I’m not ready yet. Their post is super slick and at first glance it looks easy to reproduce.
I’ll keep an eye on the other thread and try to come up with something out of chromoly for now.

I have a lot questions about welding titanium but I’ll start another thread.
Thanks so much!

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