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Old September 18th 18, 11:21 PM posted to rec.bicycles.tech
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Default Shimano 3CC hub adjustment?

On Tuesday, September 18, 2018 at 10:04:02 AM UTC-7, Frank Krygowski wrote:
I'm finishing up the build of a sweet kids bike, including a NOS Shimano
3CC coaster brake hub of unknown vintage. (Thanks again to Andrew as the
source of the appropriate but rare shifter.) The bike is a very
lightweight and pretty little antique. It also has hand brakes.

The bike is in my workstand and ready to go, but I have one worry. When
turning the cranks, there seems to be excess resistance. It's not the
bottom bracket, because I overhauled that, plus the cranks feel very
free during the forward or backward motion until the drive or the brake
engage. It doesn't affect coasting; the rear wheel seems to spin very
freely, so the coaster brake is not dragging. The friction seems to be
in the drive motion itself.

(About five and ten years ago, I resurrected two other bikes with
Shimano three speed hubs and don't remember feeling this resistance. But
that was long ago.)

I've added lubricating oil via the axle's pushrod hole, but so far I
perceive no difference. I'm (understandably?) reluctant to disassemble
the hub, not only because I'd like to deliver the bike in three days. Is
there a reasonable chance it will "wear in" and loosen up? Should I
consider a solvent flush and adding oil? Or I wonder if there's a
bearing adjustment that applies to the drive mechanism, separate from
the main wheel bearings?

I've gazed at the Shimano hub manual available at Sheldon's site
https://www.sheldonbrown.com/sutherl...-5-shimano.pdf
but at least so far, I don't recognize a solution there.

Any tips?

--
- Frank Krygowski


You should know everything to look at: spin the rear wheel to check hub bearings and see how long it takes to slow to a stop.

With the chain removed spin the crank which is the probable source of the resistance. In general the old manually adjusted cranks are over-tightened.

Third source is that the chain has been adjusted too tightly.

Then of course you should look for dragging handbrakes and misalignment that causes the tire to rub against the chain stay.
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