So I'm a new Brompton owner and really like the bike. Sadly I've recently been having a few issues that it unfolds itself while I'm carrying it – see images. It looks as though the plastic hook on the fork isn't gripping the chain stay sufficiently deeply and that's causing the bike to unfold while I'm carrying it, which is really irritating. What might I be doing wrong? Thanks in advance for any tips.
by bike_chap
5 Comments
u need to adjust the seatpost stopper which is located in between the seat stay and the rear fender, exactly behind the rear brake caliper if u are looking at yhe bike from the rear.
Try unscrewing the seat post stopper a little. This pushes the rear wheel closer to the frame when when folded so the front hook has more to grip on to.
The plastic hook doesn´t keep the bike folded, lowering the seat does
You can consider getting a frame strap to prevent unfolding
It’s a common purchase for Bromptons, and it’ll at least fix your problem for now
I think it might be either your seat post isn’t low enough to contact its locking block to or your locking block needs adjustment; got to tighten it a bit more to your preference: between tight enough to keep it folded with your tolerance of wobble/play and loose enough to lower your seatpost easily without resistance.
Here’s a excellent video from BrilliantBikes:
[How to adjust the P / T line Brompton locking block](https://www.youtube.com/watch?v=dW2KCCRxH8U)
Hope it helps, keep us updated.
Have a lovely day.