Sirrus Rider said:I have an interesting problem. I have a Raliegh twenty with a nearly new
Sturmey Archer 3 speed hub. The hub engages fine in gear 1 and 3; however,
middle gear either engages for a millisecond before breaking free and going
"neutral" or just never engages. Any suggestions? Everthing is lubed as it
should be.
The AW system drives directly to the hubshell in 2d but has a foible in
that the clutch passes a 'neutral' space when lifted off the 3d gear
pins and before engaging the dogs of the planet cage in 2d. It's likely
a control system issue, not internal.
Inspect the gear wire for kinks, the casing for damage and oil the wire
at both ends so it moves freely. Then inspect the gear indicator chain
for damage and oil it. Replace damaged gear wire, casing, indicator as
needed.
Ensure any bolt-on cable fittings are tight and do not slide under
pressure. Oil the screws so they tighten properly.
The shifter cannot be fully tight on the handlebar as it will bind. Oil
inside the shifter.
If all external controls look good and move easily, check the bearing
adjustment. There should be a trace of play at the rim. Bearing
adjustment must be done on the left side. Oil the hub internally if you
haven't already.
Adjust such that the wire is slack in high and tight in low and you're
ready to ride!
Jobst notes that steady pedal pressure in high gear will cause the
clutch to climb up and over the tops of the pins. This is an inherent
'feature' of the design as the clutch and clutch carrier do not run
perpendicular and concentric to the axle in practice although it would
seem so in the drawings.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971