In the fourth in our ‘Processes behind the M2’ series we take a detailed look at how bonding has enabled not only new design features but also a more compact fold.

Why change the process from welding?

After the queue for welding bike frames went from 3 months to 18 months during the COVID pandemic, we had to find a new way to build bikes and turned to the automotive and aerospace industries for inspiration.  FLIT’s design philosophy is to adapt and turn every hurdle into an opportunity to improve, and this was certainly the case with frame manufacturing methods.  Changing from welding to adhesives created an opportunity to redesign the look of the bike, creating a cleaner, sharper, distinctive 21st century look and feel.

The new manufacturing technique has also let the FLIT engineers make the most of other advantages too: the lack of distortion during welding means we can make the fold much more precise.

The heat used in welding leads to distortion.  This is a perfectly normal part of the welding process but has to be accounted for. On non-folding bikes a little frame distortion isn’t too noticeable, but with folding bikes, a small difference in frame alignment can cause a misalignment when folded. This means in turn that parts don’t lock together or slide into gaps where they should.

When bonding a frame there isn’t any of this heat-based distortion.  This has meant that we can be much more precise with the fold.  This is particularly evident when looking at the clearance between the frame, wheels and handlebars when folded.

“What started off as an experiment internally has become our main process for making frames and it brings with it a lot of advantages”

Dave Henderson, Lead Engineer

Click the image below to watch Dave explain why and how we’ve used bonding in our frame manufacture:

There are some other benefits to bonding the frame too.  We can use a mix of materials that welding doesn’t allow, meaning we can pick the most suitable material for each part of the frame.

Bonding also gives us options when it comes to finishing the frame.  Where previously we had our frames painted we now have them anodised (a process that is much more difficult on welded frames). Anodised finishes are more hard-wearing than paint as they can’t be chipped.

So overall, what started as a solution to a supply chain constraint, has led to:

1. A more compact fold
2. Use of better-suited materials used in construction
3. Harder wearing frame finish
4. A sleeker more modern frame design