# Brompton derailleur shifting problems



## alicat (10 Mar 2013)

Last weekend I hijacked Lorrie's New Brompton thread - sorry Lorrie - when I was having trouble with my P6R-X,which has stopped shifting to the small sprocket. Brommyboy was very helpful but the problem hasn't gone away so I am starting a new thread. 

The symptoms are that I can't engage the smaller sprocket and the lever seems reluctant to go slack.

I have cleaned everything and checked that the M£ screw joining the dogleg to
the chain pusher/actuator is just off tight.

I am in the process of changing the cable because I can see a crack in the
housing but have had to stop because my 1.5mm hex key is slightly too large
(part of a cheapish multi-tool) for the grub screw on the trigger. Filing it
off doesn't help.

The cable pusher seems to have two faults:

1. In the Brompton data sheet relating to retrofitting a derailleur
(http://www.sjscycles.com/pdfFiles/drretrofitds.pdf) it says:

'Make sure that neither of the two setting screws in
[the cable pusher] is projecting inwards from its hexagonal
housing.'

On my cable pusher, the two screws are definitely pointing inwards according to
fig DR4.

2. The data sheet goes on:

'It is best to ... keep the head of the M5 x 12 screw and
the thick spacing washer W in contact with the
bearing during assembly. Do not omit this
spacing washer or allow it to fall off during
assembly.'

The washer in my cable pusher seems of normal thickness.

Is it time to buy a new cable pusher or can I just tap the screws back and fit a
thicker washer? If so, does anyone know how thick it needs to be?

For the first time I am out of love with my Brompton and cursing the special
parts regime. I work away from home during the week and do about 16 miles a
day. Having only three gears, especially the wrong three unless I remember not
to touch the derailleur lever, is getting a little wearing.

Many thanks for any help

Alison


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## alicat (10 Mar 2013)

I've got the grub screws in the right place using a 2mm hex key so that's a start.


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## alicat (10 Mar 2013)

Well, I've fixed it. The main problem was the high limit screw needing adjusting.


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## Pale Rider (11 Mar 2013)

Glad you are sorted, and thanks for posting the data sheet - there's some useful tips on using the derailleur on the last page or two.

Which is just as well, because I barely understand the first 10 pages.

At least with a Brompton such information is available - not always the case with other bikes and bits.


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## Crankarm (11 Mar 2013)

Chapeau!


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