Post-2017 shifter problems?

[truman sparks]

Over the past 12 months, my 2 year old S6R has given me no end of bother with the rear derailleur struggling to shift from larger to smaller sprocket. Dismantling, cleaning and lubrication of the chain pusher has had no effect and limits screws set perfectly, yet it consistently fails to travel to its full extent when the shifter is actuated.

In November 2019, I took this back to my Brompton dealer, who could not get consistent shifting and subsequently replaced the entire rear derailleur assembly from the integrated lever to the chain pusher assembly, which resolved issue until now; I am now back where I started...

Searching online, I came across this:


View: https://www.reddit.com/r/Brompton/comments/9zyi2q/fix_for_poor_shifting_on_post2017_26speed/


and YT revealed this...

View: https://www.youtube.com/watch?v=EwYEYO3h2Po


The guy in the video has a conversation with Will Butler Adams and there seems to be some 'issue' with the shifter itself - too much friction/plastic to plastic contact on lever & level spindle for the chain pusher leg spring to overcome. Brompton have suggested that the issue affects bikes in hot and humid climates, although one of the BTL comments is from someone in the NW of England and I am in S Scotland, both of which I can attest to being damp and not often warm

Anyhoo - I followed the steps in the video and disassembled the shifter; lo and behold the chain pusher and cable assembly move freely and easily, so there seems little doubt that has been the problem all along....I have applied the recommended fix of light sanding to reduce internal friction, relubed with silicon lubricant and Robert is you father's brother, as they say...

Interested to know if anyone else has had the same issue - and what Brompton's response has been, as I understand they are asking their dealers to do the same as in the video above...

 

[berlinonaut]

I doubt that diagnosis from the video a bit. There have two known occurances: the one in the video and before that the one on reddit, both in hot and humid asia. The guy in the video has very doubtable expertise regarding Bromptons and certainly from two occurances, both in the same climate conditions, one can hardly draw the conclusion that there would be a design fault and the root cause would be as outlined in the video or the comments to it. Especially given the fact that until now more than 100.000 Bromptons with the new shifters have been made since their invention at the beginning of 2017.
Indeed the new shifters seem to be a bit more problematic than the old ones - look prettier but seem to be less robust. With the two-speed shifter I know of two typical issues: One being that the little hook on the top of the chain stay gets "unhooked" (with drastic consequences for the shifting - fix takes two seconds: hook it back on). Second is that the inner cable is a little bit disintegrated, causing massive shifting problems. There must be a third as a collegue of mine has the same issue with his two speed currently here in Berlin and unfortunately it is humid but not hot here at the moment.
Regarding the three speed shifter I've heard about issues - usually the shifter got exchanged by the dealer as it happened within warranty. There was no clear root cause and no real search for it. So i assume that there may be a variability in the quality of the shifters (or lack of quality control) that leads to some being not good enough longterm. Something like that. I do not believe the story in the video as issues pop up independently from the climate but are at the same time not totally common. Also I did not see where the "guy in the video has a conversation with Will Butler Adams"?

 

[u_i]

I have a 2016 Brompton and with time switched to non-Brompton shifter that I first dealt with putting on post-2017 cable configuration. However, that lead to shifting problems which were not there and such as you described. I attributed these to the piece joining the two stretches of the cable and rubbing against the cylinder in which it moves. I went back to the earlier cable arrangement which required putting an aftermarket bolt that catches the cable by the derailleur. I eventually put also an stronger return for the derailleur that you can get from bikegang. I think it is by H&H.

 

[truman sparks]

I doubt that diagnosis from the video a bit. There have two known occurances: the one in the video and before that the one on reddit, both in hot and humid asia. The guy in the video has very doubtable expertise regarding Bromptons and certainly from two occurances, both in the same climate conditions, one can hardly draw the conclusion that there would be a design fault and the root cause would be as outlined in the video or the comments to it. Especially given the fact that until now more than 100.000 Bromptons with the new shifters have been made since their invention at the beginning of 2017.
Indeed the new shifters seem to be a bit more problematic than the old ones - look prettier but seem to be less robust. With the two-speed shifter I know of two typical issues: One being that the little hook on the top of the chain stay gets "unhooked" (with drastic consequences for the shifting - fix takes two seconds: hook it back on). Second is that the inner cable is a little bit disintegrated, causing massive shifting problems. There must be a third as a collegue of mine has the same issue with his two speed currently here in Berlin and unfortunately it is humid but not hot here at the moment.
Regarding the three speed shifter I've heard about issues - usually the shifter got exchanged by the dealer as it happened within warranty. There was no clear root cause and no real search for it. So i assume that there may be a variability in the quality of the shifters (or lack of quality control) that leads to some being not good enough longterm. Something like that. I do not believe the story in the video as issues pop up independently from the climate but are at the same time not totally common. Also I did not see where the "guy in the video has a conversation with Will Butler Adams"?

As I said, one of the BTL YT comments was from someone in NW England with the same problem; I have now had the same shifting problem twice, occurring after around 9 months of regular use each time and in the second instance after everything - including cable - was replaced. There is definitely an issue with my LH shifter, as releasing the cable from the shifter end as shown in the video results in friction free movement of cable/chain pusher assembly. Never had issues with RH shifter though. I'm more inclined to think that it doesn't hold up well in damp climates...YMMV

WBA from 13:40 ish onwards in video - although you don't hear his comments directly.

If only Brompton could do away with this unnecessarily complex shifting arrangement by using a decent wide range IGH in the first place...(I know Ben at Kinetics in Glasgow has various aftermarket solutions along these lines, but costly on top of the Brompton pricetag...)

 

[berlinonaut]

WBA from 13:40 ish onwards in video - although you don't hear his comments directly.

Ah, ok. I just knew an older version of the video w/o the WBA-part (or I forgot about it). The author popped up in the German Bromptonauten forum a couple of months ago out of nowhere making a bit of fuzz about this video (which was brandnew at that time) and his "amazing" knowledge and insights about Bromptons and he faced "a bit" of pushback in the Bromptonauten forum as most of his "new" insights were totally trivial and not at all new (and sometimes even wrong) and even more because he did just hit and run posting a gazillion of links to his various social media presences in the forum instead of taking part in the discussion, so basically just spamvertizing his videos and other social media presences. So to me not at all a trustworthy source.

 

[gizmo1994]

I had shifting problems with my early post 2017 left shifter. Everything was fine until about May time when the temperature touched 25c. Then it stopped shifting. In the evening, once it had cooled down, it was fine. Thought it was the pusher at first so I focussed on that. Then noticed that if I twiddled the adjuster nut on the shifter while trying to shift then it would work. So the problem was in the shifter. Took it apart, removed the lever and just reamed it a teeny bit larger using emery paper wrapped around a large drill bit. Cleaned and greased then put it all back together. It has now been fine in all temperatures up to 42c. Pleased with that.