Hi everyone, my Brompton 6-speed has suddenly stopped shifting. When I try to change gear, it just makes a weird sound and doesn’t move.
When I checked, I found that the gear cable is frayed/damaged right at the little plastic cable guide under the chainstay (pics below). The guide itself also looks slightly bent.
Questions:
• Could this frayed cable at the guide be the reason the derailleur won’t shift at all?
• Do I need to replace just the gear cable, or also the guide piece under the frame?
• Has anyone done this replacement before — is it DIY doable, or better to take it to a shop?
by Rezaak26
2 Comments
The frayed bit is where the cable ends that shouldn’t cause any shifting issues, it’s an easy DIY swap there’s multiple YouTube guides on it.
My advice would be look at your shifter first and see if that moves and it might be something inside which has broken.
See if you can determine if the cable and cable guide are moving even a little bit, when you move the shifter. From the picture it unsure if the “fray” is actually causing a lack of movement. The first troubleshooting tasks to try:
• Clean the cable guide and chain pusher. Then apply Bike Lust, which functions as a silicone film lube that has less attraction for dirt.
• Possibly, the control cable has developed resistance within the housing due to some dirt/dust accumulation or due to gumming of lubricant. By injecting a synthetic oil into each end of the control cable housing, generally overnight, the oil will migrate the whole length of the control cable and then the cable will move freely. Inject/apply the oil at the exposed control wire cable where it comes out of the housing. Even applying the oil at the rear end of the cable housing can be sufficient, if the Brompton is positioned with the rear wheel higher than the front, to facilitate the oil running within the housing towards the shifters.
• The Bike Lust can be sprayed into the shifter as well to make the parts function well.