Sunday, May 12, 2013

Need advice - Chain falls of chainring after unfolding

OK y'all, I need some help.  Ever since I've installed the standard size chainring (and installed a longer chain with 100 links) I've had trouble with the chain falling off the chainring when unfolding "briskly". That is, unfolding fast in one motion.  This doesn't happen every time, but probably about 2/3rds of the time.  The B never did that with the original (reduced) chainring.  Any ideas?

Al from Portapedal said that I might be a tired (worn) chain tensioner and is going to be sending me one to see if it helps.


  1. Fernando:
    I haven't had this problem. I would be curious to see what your diagnosis and fix are.

    Peace :)

  2. According to Simon Koorn's chain length doco in BromptonTalk Wiki at the Brompton 44/16 (BWR Reduced) chain would have less slack than the 50/16 setup. Is your unfold the "unpark" step or the "Peter of NYCeWheels" front wheel unfold with unpark flick? The flick would put a lot of side-flex on the chain.