On my previous post I got to discover that the new design for the 2017 Brompton bike model is much more robust. Didn’t get to understand if it was designed on purpose or was a technical difficulty. My hunch was that they enjoyed the design and it made construction simple. However with experience they concluded that it was a problematic design and went for a new design. They could have just reduced the central bar length but instead almost removed it to a more challenging design at least for manufacturing.
FreeCAD produces nice images and this one is an undeformed vs deformed shape. Here I think it is visible that near the stem is where most of the stresses will be generated. So if you have a handlebar from a bellow 2017 model take special care to not pressure in an exaggerated manner the handlebar down.
Special thanks: I would like to thank the FreeCAD forum team and in particular Bernd for providing troubleshooting for FreeCAD and showing how to do the deformed and undeformed image.
While browsing the Internet I found some past references to Brompton Handlebar cracks near the bending elbows. I noticed my colleague Brompton had a different design and thus concluded that probably the Brompton bike team, decided to turn the handlebar more robust.
Check out my previous post to know what I am talking about. Click here
I notice that I make some force to the ground direction when pedalling and curving, special when the road has bumps.
In wich elbow will the stress higher and the cracks be formed? I will be continuing on this subject, so please stay tuned.
I started my week looking at my Brompton bike handle bar and noticing that a friends bike had a different one. Same model type but with a different design shape.
My Brompton version is a 2017 model however my friends model is a 2015 model.
Notice the length of the central U shape arms. Smaller?
In my bike version there was a reduction of the length of the straight tube and the two bending zones are pretty near .
I have to mention that this changes a bit how the Trigo Brompton bike acessory fits. Why? On the first design (2015 version) the accessory at the bike folded state will be positioned much higher far away from the wheel axel giving space. In my version it gets aligned/touches making my life just a bit more difficult to fold the bike with the go pro attached.
I am wondering why they made the change. Was it due to reduced stiffness? Cracking of the handlebar?
I really liked the biking handling the new handlebar offers it feels great and allows me lean a bit when curving.
Everyday I have to bike to work. In my day to day comute I can only imagine a Brompton to the help. I am fast and furious biking and when I arrive to my work destination like a transformers I can reshape my bike to soothing small that doesn’t look like a bike. Thats nice!!! This bike is my companion it goes with me to work and takes me back, day and night. A bike full of engineering, that looks simple but has a few thoughtful engineering details that make it’s design unique. Firstly let me introduce the symbols. One of them is the Brompton tag a reference mark for every Brompton bike lover.
The next detail is near the pedal the folding guide.
Not part of the Brompton brand but my personal favourite tyres the Marathon tyres which also fit very well with the big but also give the night effect circular reflection.
And I could not forget the pentagon clip holder. For those who prefer to carry luggage on the front these are the two screws that hold everything together.
This bike has a lot of interesting things happening all around.