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.

19 COMMENTS

  1. Wow, what a find. It worked for me too! Upon closer inspection, it looks like one side of the handlebar catch has a thicker side that presses against a small plate at the bottom of the head tube, rotating the fork and the wheel a bit when folded. When you flip it, you can also take out the wire part and insert it to the top side as well.

    Could it be that this is simply an assembly mistake? I wonder if it’s factory or dealership who mounts those catches?

  2. I have had an M6R since June and have noticed this problem rolling over bumpy surfaces but had no idea how to fix it until now thanks to you!
    This problem has discoloured the black spokes and rubbed some metal off off the indicator chain.

  3. Whew! Same problem here, and same solution worked.

    From reading the datasheet that tim posted, I see how it works – the catch is thicker on one side than the other, which changes how it hits the little petal-shaped protrusion on the handle bar riser when it is folded up. Flipping the catch over makes the fold tighter (but ever so slightly larger), preventing the rub,

  4. Holy crap! Amazing! I bought a 6l last month and this has been the biggest pet peeve of mine. I even asked the place where I bought it–Brompton Junction, no less!–and they did not have a solution as easy and elegant as this! Thank you! I cannot believe how much of a difference it makes–night and day. It’s not just that the sound is gone, it rolls SO much better!

  5. It worked for me as well. The trick works because, the handlebar catch has a little bump on the side. I think it was mounted wrongly at delivery or seller. If you look detailed at the catch you can see it. So if you mount it flipped, it creates some space, so that the handlebar can not turn certain point.

  6. Bravo! chez moi pareil ça fonctionne même avec les roulettes d’origine j’ai inversé l’attache et miracle thank toi

  7. merci !!! je viens d’inverser l’attache et effectivement je n’ai plus de frottement chainette/rayon !
    super de partager cette info !

  8. Interesting fix. You could also push down and out lightly on the front mudgaurd stay (where the black L catch is). Those mudgaurd stays are flexible and by pushing it down slightly you raise the sitting position of the front tire in the folded position while maintaining the tighter fold.

  9. I have a new Brompton Electric. Same problem, was gutted when dealer told me the Electric can’t be rolled when folded! Tried your method but it didn’t work. Seems the latest Brompton has a new design of stem tube catch which corrects the issue on non electric models. The mudguard stat idea doesn’t work either as the Electric has asymmetric mudguard stays. So on the Electric the problem remained. The side catch where the front wheel hangs off the frame when folded is longer and flatter on the electric model than on non electric models. This causes the front wheel to be a little further from the main frame (the wheel needs the extra space because of its motor’s wider dimensions) but it also means the wheel hangs lower, touching the floor, presumably because the weight of the 3kg front wheel is considered by Brompton to be too heavy for side catch and hinge to hold. Our successful workaround was to fit a strap to the main bike tube with the plastic buckle underneath at a point where the main tube rests on the rear tyre when folded. The added strap causes the main tube and all parts of the bike to be slightly higher from the ground creating the clearance needed to roll. We added a piece of old tyre inner tube under the strap to stop it from moving when unfolded. It works! The strap we used came with a LiteLok Silver lock (which we will use on country walks to secure to a remote post or tree); the straps for LiteLok Silver are silver and black and suit the Electric’s white and black livery, so quite aesthetically pleasing as well as functional. No doubt grime will accumulate around the strap so I’ll need to wash it from time to time to prevent chafing of paint. The strap is located where main tube sits on tyre – as it happens this isn’t where you carry the bike unfolded so it doesn’t interfere with that either. I’m dead chuffed!

  10. Worked for me as well 2015 M3L). As previously mentioned, there’s a little “bump” on one outer side of the handlebar catch. On mine (and presumably many others, maybe 50/50?), the bump was facing the wrong direction. When folded, the bump should contact a protruding lip on the head tube, twisting the folded front wheel into the correct alignment to avoid the indicator chain.

    Slight bending of the mudguard stay to adjust the hook can help to create the necessary free space if flipping the handlebar catch doesn’t initially help.

  11. It works! Solved the issue that was bothering me for many months. And also answered my curiosity on the use of protruding lip on the head tube. Thanks.

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