Hello,

I have a used BWR wheel from 2015.

Can I use it to turn a 2020 Superlight into a 6s with the parts from Brompton?

Thank you.

Yes of course, why wouldn't it be possible!

The Superlight frame is exactly the same as the steel frame excepted for the fork and rear triangle made of titanium instead of steel and Brompton was selling a 6s Superlight (its the one I bought long time ago).

I'll check what parts I need. For the shifters, I prefer the older parts.

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Edit: So I just need to get a three-speed "hub gear trigger" (QGTRIGB3A) and stick a "hub gear cable pulley assembly" (QCPULA) into the square holder?

Yes. You'll need the shifter,the appropriate cable for your handlebar,a Q100016 cable anchorage,and a Q100012 pulley assembly. A 2020 bike will have the shifter mounts on the brake lever,so you just need to remove the shifter from the new lever and bolt it into your old one so you won't have to play with the brake cable. When mounting the shifter,just snug the bolts. If you make them too tight the shifter won't work properly. You can use the 2spd cogs,but the gears won't be evenly spaced and the 12t cog will cause the chain to rub on the frame.

Thanks much

The bike has a H stem+handlebar while I'm 175cm/5'8.

What alternative handlebar would you suggest so it's closer to an M setup?

Its not possible to have the same height and reach as a M with an H stem, whatever the handlebar.

A low rise handlebar on an H stem can give a similar height as an M but not the same reach.

If need be, I don't have to use a Brompton handlebar.

Isn't there an alternative that would provide the same reach+height?

For the height, I was meaning an handlebar with a short rise = not from Brompton. To fin put the needed rise, just measure the height of the stem and the height of an M Brompton, the difference is the needed rise. This rise will be small, smaller than the rise of the original Brompton H handlebar.

But the reach is defined by the stem, not by the handlebar that should have its rise placed vertically (like the big rise of the Brompton M and H handlebar) to fold well.

At worst, I could use a quick-release adapter

If you can live with 5 speeds, you can get a cassette to fit your original 2 speed hub. This saves a lot of weight over installing a heavy SA internal gear hub, and requires only one shifter. H&H sells a kit, as does Cospaii. I have this setup on my Brompton, it works perfectly well. Shifting is fast and smooth, and climbing ability is much improved.

Since you've got an H,you can always lower it by just swapping the bar. Any 25.4 bar will work provided it's shorter than the stock bar and has no rear sweep. You will need to shorten the cables as well.