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Road Bike Frames, Wheels & Components / Re: 3d printed stem spacers???
« on: April 04, 2026, 09:37:59 AM »
I designed and printed my spacers on my 3d printer.
The main problem was that I have a Velobuild frame, but the integrated handlebar with the shortest stem was too long. So I bought a Kosevlobike handlebar with a shorter stem. Since the shape of the velobuild frame is not the same as the Kosevlobike handlebar, I designed a part to make this transition.
After several months dailing in my position on the indoor trainer, I got the correct spacer height. For me it was 45cm. Quite high, but I am not as athletic as I want to be. Since I don't think I will change the height anymore, I didn't design a 2 piece part. I believe this might decrease the rigidity and the impact strength.
For the materials, i used PETG.
I had bought a spool of carbon fiber enforced PETG, but I have read that the carbon fiber envorced PETG has a lower impact strenght in the Z-Axis ( https://blog.bambulab.com/bambu-carbon-fiber-filaments/ ). And for as far as i think, this Z-Axis impact strength is the most important one. I live in Flanders, and the roads and cobbles give quite some battering, which translates to impact on the Z-Axis.
And, since the impact on the Z-Axis is on compression, I don't think that layer-adhesion is a big issue.
For the creep, I have left some milimeters to retighten afterwards. If I have to tighten to frequent, I will change the material or reprint.
I used a 100% infill
I have ridden it now only for 60km. Including a downhill cobblestone section. The spacers held well.
If the spacers don't hold, I will update my findings here. So, unless if I had a very catastrophic failure, when there is no repost, the PETG spacer is holding on.
The main problem was that I have a Velobuild frame, but the integrated handlebar with the shortest stem was too long. So I bought a Kosevlobike handlebar with a shorter stem. Since the shape of the velobuild frame is not the same as the Kosevlobike handlebar, I designed a part to make this transition.
After several months dailing in my position on the indoor trainer, I got the correct spacer height. For me it was 45cm. Quite high, but I am not as athletic as I want to be. Since I don't think I will change the height anymore, I didn't design a 2 piece part. I believe this might decrease the rigidity and the impact strength.
For the materials, i used PETG.
I had bought a spool of carbon fiber enforced PETG, but I have read that the carbon fiber envorced PETG has a lower impact strenght in the Z-Axis ( https://blog.bambulab.com/bambu-carbon-fiber-filaments/ ). And for as far as i think, this Z-Axis impact strength is the most important one. I live in Flanders, and the roads and cobbles give quite some battering, which translates to impact on the Z-Axis.
And, since the impact on the Z-Axis is on compression, I don't think that layer-adhesion is a big issue.
For the creep, I have left some milimeters to retighten afterwards. If I have to tighten to frequent, I will change the material or reprint.
I used a 100% infill
I have ridden it now only for 60km. Including a downhill cobblestone section. The spacers held well.
If the spacers don't hold, I will update my findings here. So, unless if I had a very catastrophic failure, when there is no repost, the PETG spacer is holding on.