Folding Bike Design and Construction
Without getting into super technical details, how exactly is a folding bike made and what goes into the construction process of a folding bike? This article could span to be over a book long but we’ll go over the basic details without getting super technical or going too far into depth.
Why Do Folding Bikes Ride Differently?
To understand what goes into them and how they’re built, you have to understand why different folding bikes ride differently. This is what’s called folding bike frame geometry and there are a few different factors that make this up. The geometry of a bike is essentially just the seat, the handlebars, the position of the wheels and the frame. Also, you have to take what materials made up the frame into consideration because different manufacturers build frames differently.
Lastly, you have to take into consideration the quality of the hinges which is of utmost importance as it will determine the longevity of your bike. How many hinges your bike has, where they’re located and quality all make up the quality of hinge altogether.
To understand all of this, let’s first examine the geometry of a folding bike and why it matters when comparing the quality of different folding bikes. If you, for example, have a bike with really small wheels, the bike wouldn’t have steady balance if it weren’t for some design decisions with the bike. When the designers are mapping out how the bike is going to function, there’s some physics involved in how the bike will handle itself regarding how everything is laid out.
The designers have to figure out where to place the handlebars, where to place the seat, where to place the wheels and so forth. For bikes with smaller wheels, they have to intentionally place all of those things in places that you’d find on traditional riding bikes. This is just a very small variation between the folding bike frames positions for these elements.
Handling, however, is a bit different. If you have smaller wheels, the handling would be a bit off with a traditional bike so what folding bike designers do is they create a space that allows for a longer wheelbase and the balance issue balances itself out. It does this by allowing more weight to be centered in the front and not so much in the middle where the bike will become wobbly.
Folding Bike Frames and Their Look
When you see a folding bike, you’ve probably noticed that the frames look far different than traditional bikes and even to a lot of other folding bike frames. Why do they look so different? There are advantages and disadvantages to all frames but bikes aren’t generally designed to excel at every single aspect of cycling. Some are designed for city riding, some are designed for mountain climbing, some are designed for performance racing and so on.
If we look at the Xootr Swift folding bike, you’ll notice that there’s no hinge in the mainframe. What this allows the bike to do is to go very fast, it’s very rigid but it’s not very flexible. The Xootr Swift doesn’t fold very small and it’s not something you should probably get if you’re looking for one of those suitcase folding bikes.
The Xootr swift was designed to be unbreakable and to be a very rigid bike so designers had to compensate for this by taking away how compact it was and how stiff the frame was for folding purposes.
However not every single folding bike has to have a really harsh trade-off or have any tradeoffs at all. For one example, we can look at the Birdy folding bike and see that the tradeoff isn’t nearly as bad as it is with the Xootr Swift. Just like the Swift, the Birdy was designed to be able to be compact and not have any hinge in the mainframe. They accomplished doing this by putting both of the wheels right under the frame and they greatly reduced the size of the bike.
Bikes with Hinges in the Main Frame
Dahon is the go-to top dogs for innovation in folding bikes. They’re one of the world’s most famous manufacturers and are usually known for producing things that other companies can’t figure out how to do. The typical Dahon setup is as follows: You’ll have a telescopic handlebar, one hinge in the mainframe that will hold the bike together and some of them have another hinge to help you fold the handles over (not all of them have this).
The MuP8 is one of the most notorious examples of this design and is one of the better prevailing designs of the Dahon family. They’re known for creating wild and different looking unique frame shapes. The MuP8 is oval cross-sectioned and arched for the frame and it’s a very strong frame. It’s nearly inflexible and gives the right a very smooth ride no matter what the terrain conditions are.
Depending on the bike you get, Dahon makes a lot of different frames that are based on the aluminum material. You’ll find various degrees of quality depending on what you’re looking for and what you’re looking to spend but they’re also known as a place that isn’t known for charging an arm and a leg for their bikes compared to other companies. Plus, you get the Dahon quality.
Then, enter the competitor Brompton. Brompton folding bikes are notorious for their easy folding mechanisms and their simple frame designs that have a lot of advanced features put into them. Some of their bikes actually feature three hinges: One in the rear that will help swing the rear wheel under, one hinge that is placed on the handles to help lower it and one hinge is in the main frame as usual.
Brompton’s hinges are very tight and that’s how they maintain a stiff ride. They have very high standards for their hinges and are constantly stress testing them to make sure they’re rigid and stiff. The frames are actually steel in material and are made by hand at their home location in London. This is what sets them apart from other folding bike companies and it makes them a relatively hard competitor to beat.
The Brompton has a very tight tolerance and features a lot of high-quality materials, so they’re actually able to maintain their place as the world’s most compact and one of the world’s fastest folding bikes. Whether or not they’re the best company for folding bikes is left up for debate. However, unlike the Dahon bikes, these bikes come at a relatively hefty price.
Then, jumping back to Dahon, you have what’s known as the mini folding bike. These bikes are excellent compromises if you’re looking for something between a full-sized folding bike that can’t be carried in a suitcase and the smallest folding bikes available on the market. The dual arch frame will make them look a bit more like a standard bicycle because of how the components are lined up but they’re still small, durable and easy to compact.
The frame hinge of a folding bike is the most important part. It arguably has the most important job of the bike other than making it go which is your job. The hinge will not only help decide how easy it is to fold but how much weight it can support and a good hinge needs to be able to support a lot of pressure and rough ground so that it doesn’t collapse mid-ride.
So what exactly makes a really good folding bike hinge? One of the most important things is to make sure that it’s not coming loose while you’re riding. Every major manufacturer makes sure of that under the legal law for distributing folding bikes. How fast you can release the hinge while you’re holding the bike and how strong the hinge is are two important questions you should be asking.
Do you need tools to unlock the hinge, is there a lot of room for movement and flexibility? Lastly, you need to ask how durable the hinge is as well and don’t cheap out on a folding bike with a bad hinge. The hinge is the most important part and determines the quality of your ride.