Originally Posted by
fietsbob
Brompton used to use the shift out both ends 5 speed, then as written in the Brompton Book , the supply dried Up.
The next source was Sachs Making the first 2 cog 3 speed 6 speed , for them.(Sachs was Bought out by Sram)
Now the New source is back to Sturmey Archer, But the company changed hands and now comes from Bicycle Island, TW ROC.
Their current 5 speed wont fit in the standard Brompton rear width; less than 120mm ..
http://www.sturmey-archer.com/files/...0IGH%20C50.pdf
125 is the narrowest overlock nut spec offered.
'/,
Sorry to say this but you are a bit wrong here. Brompton used to ship the S/A Five-Star with two shifters in the late 80ies and early 90ies. In about 1993 they switched to the S/A Sprinter, also with five gears but one single trigger. There were various versions of the sprinter until S/A went bancrupt in autumn of 2000. Brompton switched to Sachs/SRAM gearboxes and developed the six-speed derailleur (2*3) as Sachs could not offer a five-speed that was small enough. In 2009 they switched back to S/A with the six-speed and introduced the BWR with 302% range.
For a couple of years now S/A has a five-speed that fits w/o hassle: The SRF5w. It offers 256%, is a bit hard to get hold of and suffers a bit from fiddly adjustment. Apart from that it works fine though the gearsteps are a bit on the high side (quite similar to a three-speed). As to my knowledge you can build a 10-speed hub from it, using some parts of the BWR plus the Brompton derailleur. You can get the SRF5w i.e. at SJS in the UK with 111mm OLD:
https://www.sjscycles.co.uk/hubs-int...srf5-5spd-hub/
Regarding the eight-speed XRF8w I own two of these, one of them in a Brompton. It is a really nice hub (325% range) with some specialities: Direct gear is the first, so you need either a big cog or a small chainwheel or both. I run 25/50 on the Brompton and the chainwheel could/should be a bit smaller. It offers evenly 15%-steps with the inner 6 gears and 30% with the outer two. So for daily riding you are well set up and have an upper and a lower rescue gear for the extremes that you would not hit every day. In difference to a Shimano eight-gear you do not need to spread the Brompton's back-end but you have to lengthen the chain-tensioner. No need for a kit tough it surely makes the move a bit more comfortable. Unfortunately the hub is again very fiddly to adjust plus it has noticeable drag in the gearbox. And it has not the best reputation regarding long-term reliabiliy. This reputation may have been partly earned by it's older brother, the XRF8 (w/o the "w") - especially earlier versions of this hub tended to die early. Worst about the XRF8w in the Brompton aside from shifting issues from time to time is that you add about 1kg of weight. So you probably do not want it if you have to carry your Brommi regularly.
The SRF5w on the other hand does only add very little weight to the Brompton (about 200g) and it fits like a glove. Plus it is massively cheaper. So it is a good alternative for those who do not like the handling or the price of the Brompton six-speed but need more range than the tree-speed offers and defitively worth considering if you want to replace an older S/A five-speed.