Brompton hub gear maintenance
My Brompton L3 has become a 2-speed, I can no longer adjust the cable tension in such a way that all 3 gears are usable. When tension is loose enough to use 3rd (direct drive?) I can't get into 1st. When the cable is tight enough to use 1st, it won't drop into 3rd. This started after I'd had the bike about 4 months (commuting 50 miles a week).
I don't seem to be the only person who's had this problem, I found someone on the Bromptontalk group on Yahoo with same issue:
I'm in 2 minds about whether to try stripping down & lubing the hub myself or take the complete bike back to LBS where I bought it and ask them to fix it or replace the hub under warranty. Reluctant to use latter option as I suspect it would mean the bike being off the road for a lengthy period and I use it every day.
Anyone heard of this type of problem with SRAM Spectro T3 or other 3-speed hubs?
I do not believe that lubrication is the issue on not getting gear change and on such a new bike. I have a Brompton but it is a Sturmey Archer, I have a lot of mileage up with no problems.
I would not be very tempted to open the rear hub myself. I would bring it back to the shop and if they take longer than 1 week look for a loan or replacement back wheel with hub from them.
As an aside I have 3 bikes running, the Brompton, A Sirrus and a Mountain bike.
Although I don't use the Brompton every day I do go through phases of using it for 100 miles a week commute. It is very low maintenance. I have practically rebuilt the Sirrus but have only changed chain and spring tensioner on Brompton.
About 4 years ago I researched heavily the Brompton hub etc before buying. Your hub should run for many many many miles without adjustment.
Bottom line - take it back and get it fixed. The downside to the Brompon if that can be called a downside is that true Brompton users - that use them everyday invariably buy a second one for when problems occur with first.
This was my experience as well, except I caused it.
When I first purchased my Brompton, I rode it and never had a problem. As I got used to it, I read that a rear tire change could be tricky the first time if you've never taken the rear wheel off, so I thought I would practice to make sure I got the hang of it.
In my case, my 3 --> 2 speed was caused because I pushed the chain indicator too far into the plastic adjustor when I replaced the wheel. Not only that, but when I put it in the adjustor, it looked too loose to me, so I loosened the adjustor and pushed it up the cable. That's when my problems started, but I didn't know how to fix my mistakes.
When I finally had an LBS guy check it out, he said I only had to push the chain indicator into the adjustor until I heard two clicks - the cable is supposed to be rather slack. But he did other things as well:
- When he first examined the problem, he kept looking at the cable, not the hub.
- He unscrewed the adjustor and took it off, then he re-seated the cable over the pulley housing.
- He inspected the cable and rewove the cable end by hand as it was beginning to unthread.
- He screwed the adjustor closer to the end of the cable, then pushed the chain indicator into it a couple of clicks and tested the gear shifting.
It worked. Now I have all my gears working.
Did you, by any chance, unseat the adjustor while you were adjusting the cable tension? How far did you push in the chain indicator?