Up until now the Brompton has run flawlessly. Out on my ride yesterday I noticed some chattering (best I can describe it) noise coming from the rear 3-speed hub as I was slowing down for a traffic light. I stopped short of the light to visually look and see if there was any noticeable problem. I started pedaling again and the chattering, or whatever, was still there. I was in mid gear at the time. I flipped through the gears on the hub (not the 2-speed derailleur) and all was fine when I pedaled away from the light. Any ideas as to what that was or caused it? I examined the bike, and the adjustment for the hub is bang on. Once in awhile I have noticed an occasional odd/different sound while coasting in mid gear. At least it's still under warrantee in the event there is a problem with the hub.

Thanks
Wayne

I've had nightmares with SA hubs and rattling, but I think that the newer types should be less prone to it than the old AWs.
I'm guessing that if you hold the bike steady and try to rock the rear wheel you'll detect a small amount of play in the bearings (you have to make sure any movement detected is coming from the wheel and not the rear frame hinge). As grease migrates from certain areas and the bearing races wear fractionally the internals are given enough space to move slightly, and riding over rough ground results in rattling. Readjusting the left hand (non-drive) cone so as to dial out the play ought to get rid of it.

Incidently, you can adjust the left hand cone without taking the wheel off the bike, so long as you have the correct wrenches.

Only had AW3. and now BSR hubs .. maybe cable break in and its out of synch with the shift lever.
check the 2nd gear indicator window, adjustment procedure .

&or, just saying that ... CC all that and email the company, Brompton,
they are very good at replying to customers.

the BWR hub is made just for them .

There is a bit of play, but it's minute. So far it hasn't happened again, but the bike shop (Portapedal Bike) have been made aware of the issue, if indeed it is an issue, and mentioned to bring it in if it happens again and their mechanic will have a look at it. I haven't had the bike a year yet and all parts etc., have a two year warrantee. If there is a defective hub, they told me that they would have the whole rear wheel assembly replaced.

I had everything looked at and adjusted after the break in period. All is well. I checked the indicator widow while in 2nd gear, and its fine. The hub shifts properly. Will head on out later for another ride and check it out again.

Whenever I've serviced a SA hub within a few months the cones have needed readjusting, I take it as a matter of course. Usually the rattle starts when coasting over rough ground but not under pedal load, then eventually it happens whether pedalling or not as things loosen further.

Due to the way the washers are folded over there is a quarter turn of adjustment.
nothing less.
but the folded edges of the washers also prevents it from that adjustment changing.
It's pretty locked in place.

Ive pulled the right side cones to pack the bearings with waterproof grease,
It also acts to retain the lighter oil , such as Phil tenacious , from seeping out
a the same time, in sequence. as I did the Left.

Regarding the readjustment of the cones; like I mentioned, on mine there is a very, very small amount of play. Should there not be any play at all?

I've heard different schools thought when it comes to hub cone adjustment in general and nothing specific to SA hubs. The general advice is to aim for the sweet spot between eliminating play and avoiding binding, and it depends on the quality of manufacturing as to exactly where that lies. I've often been dissatisfied with the efficiency of SA hubs so I've intentionally adjusted for a tiny amount of play, but generally this results in the internals rattling once grease has migrated/settled, so now I dial out all play with as much care as possible to avoid over-tightening, which creates significant drag. It's a delicate procedure and one I'd prefer not to leave to a dissinterested or distracted shop mechanic.
Of course, your issue might be something else, but in my experience this is a common cause of SA noise. Another diagnostic test is to see if it increases when running higher tyre pressures.
It may also be the case that the factory grease lubrication was innadequate, but that's probably something to worry about further down the line.

The fact that you noticed it whilst slowing (i.e. not pedalling) and it seemed to disappear when accelerating is in accord with the problem I'm describing. Pump the tyres really hard and coast over rough ground.

I appreciate all you help here. Actually it's while pedaling. No noticeable problem while coasting. The noise didn't go away until I started going through the gears. I'll keep riding until I notice the issue again, and if does come back, at least the bike still has over a year of warrantee on mechanical defects. Thanks again for the assistance.

Cheers
Wayne

Oops, missread the initial post. Keep an ear out for whether it's limited to a specific gear.

then you might be adjusting too tight .. may only be 2 bowls of Porridge , for Goldilocks ...