I was so excited to try my new Brompton Black Edition folding bike as I thought it would be a perfect commuting solution for me. However, I had a problem with this bike right on the first day riding to work.
In fact, the riding performance is good and I just found out the issue when rolling the bicycle in shopping cart mode. Specifically, when I pushed the handlebar to roll the bike, I started hearing some loud pinging sounds. After some investigation, I figured out that the noise comes from the collision between the front wheel’s spokes and the chain tensioner nut. The nut is installed outside of the rear derailleur and it helps keep the chain taut when the Brompton is in folded or unfolded position.
The nut protrudes more on my bike since this is the 6-speed Brompton M6L. Therefore, when I roll the bike, the front wheel makes contact with the ground and rotate as well. The tiny rolling wheels on the rear wheel obviously can’t provide enough clearance to lift the front wheel. So, when you roll the bike, there are more chances the spokes will hit the nut. I had to tilt the bike slightly to temporarily fix the issue. If the problem persisted, it would be a huge disappointment.
It’s really unacceptable as a leading folding bike manufacturer like Brompton could make that design defect when everything else is brilliant. I had to find a solution myself and surprisingly, a simple change fixed it.
All you need to do is screw the handlebar catch, flip it over, and then screw it back again. I did the trick and couldn’t understand how it solved the problem.
If you have the same issue with your Brompton, let me know if the trick works on your folder.