Brompton 2-speed shifting question.
 

I bought my Brompton new in 2014. It is a 6-speed. As well as I can remember, when I first got it, it shifted from the smaller rear sprocket up to the larger by simply on move of the 2-speed shifter. For the longest time, it requires a conscious second push down to start the shift. I asked the dealer about this and he said that was normal. Over time I have had to increase the tension in the cable by moving the ferule to furthest position from the trigger in the shifter mechanism. My question is, is this normal?

NB: in addition to the dealer there is a Q&A directly available through the Company Website, perhaps you can ask there?

cable operated systems do change as the components settle in , and perhaps get contaminated inside the housing run.



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Not sure what "on move of the" means, but you should…
1. Clean the gunk off the derailleur: It's a well known issue on the Brompton
2. Get a new cable + housing.


Brompton shifting problems ? Ready-Made

I mean moving the lever into the other position. I have to move it to the other position and then depress it again to get it to release the chain and make the shift.

Try just holding it all the way over until the shift takes. That's how friction shifting works, but you're trying to do it as if it's just a button you push and it does it itself. Nope. You gotta move that derailleur until the chain catches up and moves to the other cog.

OK, but you do not have do this to shift from the large cog to the small. How come? Gravity?

It's been a long time since I friction shifted.

The spring is biased towards the small cog, i.e., if you disconnected the cable the derailleur would snap to the outer/small-cog position. Combine that with the chain having an easier time falling to a smaller cog than climbing to a big one and, yes, you will get a gravity effect.

This is not to discount that new cables will help, but you'll end up back to slightly harder shifting again soon enough. That wire gets pulled through a long, convoluted run of housing which gets twisted around a lot if you fold regularly. It's just the nature of the Brommie beast.

Thanks, that is what I wanted to know.

I've a Brompton a couple of years older than yours. It has seen a fair amount of work from daily commutes to cycle tours in Cambodia and Australia, but I've never experienced this.

What is your gear changing method? I have always ignored Brompton's advice and back off pressure when changing the front two gears and back pedai for the hub gears.

My technique is similar to yours in that I back pedal for the hub gears and back off the pressure for the "derailleur" gears but I do pedal forward lightly to make the the "derailleur" shift. My question just involves having to double press the derailleur. I suppose it would make the shift in one press if I press it all the way down and hold it there until it shifts, as Joe Remi suggests. Is that really the nature of the beast? I don't think I was doing that when I first got the bike.

You know, I've never really thought about it, but haven't noticed anything other than it is a stiffish movement. Never had to double press the derailleur, though. I'll check when I get back home in a couple of days.

I did have the same thing on my Bianchi, though, and a new cable solved the problem.

Just checked on mine. The derailleur is a smooth as silk and operates first time round. The Hub gears are a little stiffer, but, again, no need for a double press.

I'd check with Brompton, if I were you, their support is pretty good and that doesn't seem to be normal behaviour.