Upgrading 6speed Brompton to new style shifters

Mattl_89

New Member
Hi guys,

I want to upgrade the old style shifters / brakes on a 6spd Brompton to the post 2017 integrated kind. Can this be done?
 

steveindenmark

Legendary Member
I would not consider it an upgrade.
 

berlinonaut

Senior Member
Location
Berlin Germany
I want to upgrade the old style shifters / brakes on a 6spd Brompton to the post 2017 integrated kind. Can this be done?
Depends. No issue on S- or P-bars. With the older style M-bars it is doable but as there is formally too little space you have more or less one single possible position for brake handles and shifters and still a little less space for the grips than before. So it depends from your bars to a degree. Be aware that with the six-speed you'll need the newer dogleg for the derailleur as well. It is not expensive but easily forgotten if you only look at the shifters and only regonized when you are in the process. Overall with new brake handles, new shifters, new cables an a new dogleg still a relatively expensive exercise.
 
This was not the question but as you seem to have a strong opinion: Why?
Not steveindenmark, but there have been reports of shifting problems in high ambient temperatures, apparently due to plastics expanding. There's a YouTube video where a guy takes the shifter apart and abrades some parts to increase the clearances.
 

Tenkaykev

Veteran
Location
Poole
Not steveindenmark, but there have been reports of shifting problems in high ambient temperatures, apparently due to plastics expanding. There's a YouTube video where a guy takes the shifter apart and abrades some parts to increase the clearances.
I did the same with Mrs Tenkays Brompton when the shifter seemed to bind from time to time. Used some superfine wet and dry and not been a problem since.
 

berlinonaut

Senior Member
Location
Berlin Germany
Not steveindenmark, but there have been reports of shifting problems in high ambient temperatures, apparently due to plastics expanding. There's a YouTube video where a guy takes the shifter apart and abrades some parts to increase the clearances.
This is the trouble with reports on the internet. Yes there have been a handful issues reported and there has been one person being *very* vocal about that (but possibly less competent regarding the problem and the Brompton in general). A bunch of shifters have been exchanged over the last 3,5 years since their invention.

On the other hand: The new shifters have been invented at the beginning of 2017. Since then, roughly 200.000 Bromptons have been produced, all equipped with the new shifters apart from the few single speeds. What we see is that the internet and forums as part of it often are a giant echo chamber - people repeating what they have read or heard "somewhere on the internet" but w/o relating to own experience or bringing what they read in relation to production numbers. With 200k samples out there the number of problem reports is minimal. I'd assume that Brompton had a bad batch of shifters or some variability in production relatively early after their invention. These shifters were and are causing problems and these problems are vastly overcommunicated in forums. What do you think: If the shifters were all supposed to fail and 200k samples are out there: How many problem reports would you recognize?
 

u_i

Well-Known Member
Location
Michigan
Well, putting the ridiculous YouTube video aside, I personally find the new dogleg mediocre, unjustifiably difficult to work with and trouble prone under more challenging conditions in the surrounding, of mud, dust or snow. Given various challenges of folding and folded size, risky compromises must be sometimes adopted but fail to see any compelling reason for such a mediocre solution. I thought I was upgrading putting the new dogleg on my older Brompton, but after few months of struggle I kicked it off for good and life improved ^_^.
 
I thought I was upgrading putting the new dogleg on my older Brompton, but after few months of struggle I kicked it off for good and life improved ^_^.
Can I ask what you put in its place, u_i ? I see some far-East sellers have a Ti spring for this -- do you think that would help?
 

u_i

Well-Known Member
Location
Michigan
Can I ask what you put in its place, u_i ? I see some far-East sellers have a Ti spring for this -- do you think that would help?
From different solutions I found the following replacement piece to be optimal, when going with shift cable attachment on the pusher side:

You get it on AliExpress, e.g. here. There is a bolt there that grabs the end of a shifter cable on the pusher side. It is not ideal, as it difficult to thread the end of the shifter cable through. However, I found that you can unscrew the tube sticking out from this piece and drill the inside a bit. The end of a drill is conical and it makes a conical cavity iside, so when you push the cable in through the tube, it easily finds the hole that it is supposed to go into, for securing with a bolt.

Other solutions include bolts that replace one in the original Brompton piece. There is a similar problem there with threading of the shifter cable that can be solved similarly. However all those screws stick out more and the cable too, allowing for an interference with chain. The piece above is optimal in terms of compactness.
 

paulfacer

Active Member
I've just replaced the "Rabbit Ears" 3 speed shifter on my 2015 Brompton with the Sturmy Archer indexed shifter

https://www.sjscycles.co.uk/gear-shifters/3-speed-sturmey-archer-sls30t-thumbshifter-hsj962/
Hi - Having made the mistake myself of having "upgraded" to the new Brompton shifters, I'm about to do what you've done and switch the 3-speed shifter to the Sturmy Archer thumbshifter. How did you find the conversion? Were you able to simply swap out the shifter and re-use the cable or do you need to replace it? Thanks!
 

berlinonaut

Senior Member
Location
Berlin Germany
Hi - Having made the mistake myself of having "upgraded" to the new Brompton shifters, I'm about to do what you've done and switch the 3-speed shifter to the Sturmy Archer thumbshifter. How did you find the conversion? Were you able to simply swap out the shifter and re-use the cable or do you need to replace it? Thanks!
I did this also with one of my Bromptons and it is very much straight forward. Coming from the old style shifters you would need a new cable, coming from the newer post-2017 ones you could in theory reuse the existing one. However - the S/A Thumbshifter comes with a new inner cable as part of the package, so you can simply use that as it fits the shifter perfectly.
 

Tenkaykev

Veteran
Location
Poole
I did this a couple of months ago on my 2015 M6L. Swapped the Rabbit ear shifter for the Sturmey Archer indexed thumb shifter. As Berlinonaut says, the cable that comes with the SA fits perfectly.
I pulled the old cable out of the sheath and slid the replacement down the outer and trimmed the excess off.
I really like it, I'd like something similar for the derailleur. The thumb shifter is relatively inexpensive so it might be worth me having a play around as part of my lockdown therapy ^_^
 
Top Bottom