has anyone successfully used bar ends on a brompton that didnt' interfere with the folding? maybe even something longer than the ergon gp3 grip/bar end?

The NYC Edition from last year came with them.

S Bar owner here and I looked into this not too long ago. The short answer is it depends on the shape of the bar ends and the width of your handlebar. If your handlebar is around 48cm wide then the only ones that will work are probably the ones that do not aggressively curve in. Basically you get more inner clearance (bar end to front tire when folded) with wider handlebars. As far as the bar end length, my rough measurements showed that you can go with up to 16cm long (diagonal to the handlebar).

It is always windy around here and I too would appreciate longer bar ends. I finally decided to go the drop bar route with brakes which is also doable up to some extent. Waiting for funds because it involves more hardware and time. That will be my bike project this fall/winter. A D-Bar Brombton

The Ergon GP3 should be more than enough. When I added them the control over the bike went up maybe 30 percent or more. It makes a big difference.

My Friend at the Portland Oregon B Dealership, says he uses the GP 4 on his M6L.

I have the 3 on mine .. the 5 can work , if you loosen them when you fold the bike..

No, IDK how long you can get away with doing that..

Put a QR on in lieu of the 7mm bolt that is in the handle bar clamp. You can then release the QR and rotate the bar so the barends dont hit the tire. Of course, if you do the full fold often that could be annoying. BTW, I have Rivendell $10 Dutch paddle grips cut down about 1/2 inch on my barends and they spread hand pressure away from the nerve that runs up from wrist to fingers. This helps with numbness.

when I was in the bike store the bar end of the gp3 felt too small for my hand, but maybe I wasn't holding it properly? at 6"2" I have big hands, but of course on the flip side the gp5 maynot fold...with the bike.

I have an H type,2014 with GP2 but I think I could go to GP4.

The deal with those is the bar-end is an integrated extension of a grip that starts with an extended paddle section, so realistically you're using bits of both in that position. I'll bet when actually on the bike on the road, the bar-end will feel a bit longer to you.

ahh, that makes sense.. thanks so much..... so perhaps I did have my hand in the wrong position... too high up...

I typically have an open palm , over my GP 3..

Yes, that how I ride them, too. I only use non-bar-end Ergons currently, but when I had GP3 on a Dahon I tended to use that 'open palm' style: The paddle-plus-extension creates a platform that you can grip in separate sections as normal, or spread your hand over the whole area. Those Ergon folks are brilliant.