My XRK8(W) certainly has been for the last 5+ years.

Many have been critical of SA 5 speeds and 8 speeds, new or old versions.

No internal hub gear is perfect and many people don't like or find the shimnao nexus nice or reliable. Mine have been fine. My older 5 speed SA were ok to use but a pain to adjust. I sold my last Brompton as I could not find a hub that fitted the bike that I wanted to use. Maybe I should not let the internet relability reports of SA 5 and 8 speeds put me off, but I also wanted to use shimano road race levers and it started to get too much uncertianty for me to go down the upgrade path I hoped for.

The 6 speed works ok. If its your main bike you get used to it. Its tollerable. I recomend you try it and see. Personally I perfer the 3 with a doulbe chain ring.
If you dont like the 6 speed consider throwing some money at a kinetis nexus or Afline hudded brompton rather than upgrading as it will be cheaper in the long run.
I lost a bid on a low profile bared, afline 11 speed laced to a versa road race brifters on ebay. It only went for 1300 pounds. Dream bike even for a Brompton hater like Me. LoL
Failing that there are also the Mezzo folders with a standard upgrade path rear axle width.

Thanks,... I'll definitely keep this information in mind when I start the mod.

I have a Shimano Nexus 3 and 8 speed hub. Both are working good for me, but it's the 3 speed that is fickle with it's (super simple) adjustments. I just think it's time for a change, and the Sturmey-Archer 8 speed looks like my personal favorite.

And, eventually, I'll get a Brompton 6 speed,...it's in my future.

The older ball-locking standard range 5 speed hub I installed on my Brompton has been running flawlessly for 4 years; it's great for short-distance urban riding. I have one on another bike and it's not so smooth despite my attempts to tweak it.

http://bikeforums.net/attachment.php...hmentid=497003http://bikeforums.net/attachment.php...hmentid=497004Here are your pictures....

Thanks 12boy!