Quickly fix Brompton 2-speed / 6-speed derailleur shifting issues

The excellent Brilliant Bikes video is here: • Brompton 2 / 6 speed D...
In this video I go over some quick tips to fix issues with the Brompton derailleur. The real solution is to painstakingly take everything apart and clean it properly, but I go over some simple fixes which might help you.

[@goopie12-ot4so]

Oh dear. I spent so much time reading the manual and watching videos, twiddling various knobs, took the entire thing apart and put it back together... And it was just the little plastic part that got unhooked. I hooked it back up and all I have to do now is readjust the grub screws back to normal, which I wouldn't have touched in the first place if I'd found your video first. Thank you so much!

[@bradrainke4488]

Wow!! I have only rode my NEW Brompton 6SP, a few times and it would not shift. I was angry and was ready to call up Brompton. After looking at this video, the cables and the little plastic holder before the spring was out of whack. I adjusted, and violia, it shifts now. Love my bike. This video really helped and is Brilliant.

[@secondraidcycling]

Just so you know, I watched your video under an overpass in Tokyo Japan, riding on the Arakawa River Bike path. I was wondering why I felt like I only had three of six gears. Watched a more in-depth one first, and breaking the shifters down sounded like a right nightmare. Watched yours next . . . turns out while the cables weren't twisted, the buggers had managed to stack on top of each other in the little 'cage/guide' and brace tight. How, I'll never know. So thanks for saving me untold anguish and 30 more miles with only the lower gear. As a Brompton newbie, I hadn't the foggiest on the derailleur system.

[@johnzarr6590]

May God bless you! Your advice helped me avoid a $180 repair shop bill. I simply cleaned the 2 speed shifting gears, and the Brompton shifted fine again.

[@emmanear-myths4200]

Thank you. I’m 2/5 of the way through a 100km ride in France today and I got stuck on 3. Your video rescued me just now ❤️

[@ChrisTheCuriousDad]

Very helpful. Who’d a thunk all those cable could get so twisted. Thank you.

[@zedali2579]

So glad I watched this. Cables were twisted. That was it! Thank you!

[@thedelta2820]

Thanks a million mate. Was looking for two hours what was wrong and then finding that the little plastic rod wasn’t in place. All works well now.

[@patrickarmstrong1303]

Thank you. Saved me a lot of time -- it was the twist on the cable. Straightened it out and it works again.

[@terryc8164]

Useful video, and that plastic bit is well worth checking but having riden my Brompton over several years commuting in all weathers down muddy lanes etc. my 1st thought is always the chain tensioner when the 2 spd shifter misbehaves. Its simple to remove, a big nut, and if you have a 6spd like me there's the Sturmer Archer chain to disconnect too. Takes about 2 minutes to remove, then it's much easier to clean, do that and rei-nstall. That in my experience fixes it almost every time. I cleaned mine, when commuting in bad weather, every two weeks. I only once had to adjust for a stretched cable in 5 years, and maybe twice a year I dismantled the 2 spd shifter for a clean and a small drop of light oil. Its really useful to have a spare chain tensioner, a simple swap out and then clean the dirty one over the next few days. If you have an ultrasonic cleaning tank they make cleaning it a breeze too 😁

[@geoffphillips9045]

Thankyou thankyou thankyou!!!! Had my Brompton (also British Racing Green) flipped upside down in (and basically filling) a hotel room in Frankfurt, as the derailleur (or whatever it is) wouldn't go into the higher / smaller gear. First things you said about the cable routing and checking the plastic thingy was hooked in properly fixed it. Brompton's own video was naff all use.

[@niel8748]

Felix top man. My issue was the plastic clip at the back. fixed and saved going to the shop. Many thanks

[@graybags3895]

Great little vid and might I say better than Brilliant Bikes one about derailleur adjustment which misses out a load of steps and makes no reference to that horrible bit of plastic which was the culprit in my case, many thanks !

[@herrschickhose]

Thank you! I struggled for about an hour trying to fix it. Turns out the plastic piece was just loose. Really glad I found your video

[@sashaxian]

Thank you! Loosening my tightened wires worked!!! SO Easy to shift now

[@antonsmith2819]

Perfect swift solution - that pesky bit of plastic had detached itself.

[@davedawggy]

Thanks! Both my gears were getting hung up because the cables were twisted through the cage near the rear wheel and that plastic derailleur cable guide was hung up on the other cables. Quick fix thx to you.

[@ulrichgunther9905]

Unfortunately most of the rear derailleur issues arise from the shifter which gets stuck due to some kind of swelling of the plastic parts. There is a video how to fix this. CLeaning the bottom end also helps, but is comparably easy. I would not apply much grease down there as it will just attract dust and dirt which will stick to it. I keep this area dry and clean. Not the best engineered part of Bromptons.

[@XVel]

wow the shifter rotating barrel thing should be discussed more! its the easiest solution!

[@Anarchers]

Thanks for the video, I didn't realise there was a cable tension adjuster. Although it is the most likely thing to go wrong it has been functioning for quite a few years with little attention from me. Thanks for sharing.