On 1/6/2019 9:23 PM, Frank Krygowski wrote:
I built up a lovely kids bike with a Shimano 333 coaster
brake 3 speed hub. The young lad rode it on the ride we took
today.

There's been a consistent problem keeping gear #2 adjusted.
It acts as if an internal spring responsible for pulling the
hub into 2nd gear is somehow weak. That is, the little
circle with the letter N doesn't settle down in its target
hole. As a kludge, I used a bit of inner tube as a rubber
band on the bellcrank to help pull the hub into 2nd, but
that rubber decayed and I didn't have a spare. In any case,
I've readjusted it several times in the past couple months.

I'd suspect a dragging cable, except the hub shifts into the
other gears just fine. 3rd gear requires the hub to retract
the cable even more, and shows no problems. Of course, I
lubricated the cable during installation. I even spent time
grinding away part of the kickstand mount to give the
straightest possible cable routing.

Unfortunately, the bike is an hour away and I normally see
it at most once per week; so some things are difficult to
check, other things may be difficult to remember. But are
these hubs extra sensitive to cable friction? Instead of the
full housing, should I consider scrounging parts to run bare
cable over pulleys, etc?

But if anyone has tips, I'd be grateful.


Generally I'd suggest open, clean, lubricate but in the case
of an F or FA gearbox, you need the Shimano ball cup tool to
do that. Next time you're there, remove the bell crank and
see if the pushrod moves easily with your thumb. If it does,
you may merely have a sticky/smashed/worn bell crank and
those are simple to reform.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971