Drivetrain slipping when freewheeling

I cleaned my drivetrain this weekend: paraffin, old toothbrush, cloth,
then let it dry; then chainsaw oil and, after an hour or two, WD40.
I'm sure someone recommended chainsaw oil to me on this group some ten
years ago and it clings like a mother, although you have to let the
excess drip off.

This morning I felt like I was on silent running coming into work. A
real speed and smoothness improvement.

But whenever I freewheel and then started to apply pressure again, it
feels almost like the chain has (silently) slipped out of gear.
There's a second or two of no-torque and a bit of clunking that I
can't easily spot by eye (without cycling into a hedge.)

Any thoughts? None of the cables were adjusted, just lubed.

Cheers,
J-P

On Mon, 24 Jan 2011, J-P Stacey wrote:

But whenever I freewheel and then started to apply pressure again,
it feels almost like the chain has (silently) slipped out of gear.
There's a second or two of no-torque and a bit of clunking that I
can't easily spot by eye (without cycling into a hedge.)

Any thoughts? None of the cables were adjusted, just lubed.

Is it hub-gear or derraileur? (Not that any particular thoughts come
to mind for either, but it might be relevant).

regards, Ian SMith
--
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On Jan 24, 9:07*am, J-P Stacey wrote:
I cleaned my drivetrain this weekend: paraffin, old toothbrush, cloth,
then let it dry; then chainsaw oil and, after an hour or two, WD40.
I'm sure someone recommended chainsaw oil to me on this group some ten
years ago and it clings like a mother, although you have to let the
excess drip off.

This morning I felt like I was on silent running coming into work. A
real speed and smoothness improvement.

But whenever I freewheel and then started to apply pressure again, it
feels almost like the chain has (silently) slipped out of gear.
There's a second or two of no-torque and a bit of clunking that I
can't easily spot by eye (without cycling into a hedge.)

Any thoughts? None of the cables were adjusted, just lubed.

Cheers,
J-P

The freewheel clutch is gummed up, get some light oil into the
freewheel internals. If it is a trsditional freewheel, lay your bike
over on the left and drip the machine oil onto the face of the bearing
cone adjustment, turning the wheel forward should draw the oil
inside. Keep going until the clicks start retuning, then just keep
turning the wheel forwards. A similar tactic may work for a freehub
unit or you may be consigned to at least a partial dissasembly just to
get some fresh oil in there.

The freewheel clutch is gummed up, get some light oil into the
freewheel internals. *

Brilliant, thank you - I will try that tomorrow morning.

(I should have said: it *is* a derailleur, and I think traditional
freewheel.)

Cheers,
J-P

On Tue, 25 Jan 2011, J-P Stacey wrote:

The freewheel clutch is gummed up, get some light oil into the
freewheel internals. *

Brilliant, thank you - I will try that tomorrow morning.

Warning: thirty-six is a known bonkerist, and this may be nonsense. It may
well be perfect mechanical truth too.

Is the problem worse in a big or a small sprocket at all? Could the chain
be worn? If you have access to a micrometer or other accurate measuring
device (a tape measure is probably good enough, actually), you could
measure the chain pitch to see if it's stretched. If not, have a look at
how the chain sits on the sprockets along the range (probably easiest to
flip the bike over to do this) - each roller (the bits bridging the
parallel rows of chainplates that make up the linear part of the chain)
should sit nice and kentucky in a pit of the sprocket; if you find that
some of them are riding up out of the pits, that suggests wear.

I had a worn chain a while ago, displaying those symptoms, and my shifting
trouble only revealed itself after a thorough clean. Perhaps the filthy
grease acts as a sort of adhesive, keeping everything together despite the
wear.

tom

--
unstable orbits in the space of lies

J-P Stacey wrote:

Any thoughts? None of the cables were adjusted, just lubed.


Check the derailleur arm is working properly and properly aligned.
Sometimes it can hang up in a way that creates a loose chain on the top
run when you freewheel. Then when you start to pedal you have to take
up all the slack before it suddenly engages.

Tony

On Jan 25, 11:34*pm, Tom Anderson wrote:
On Tue, 25 Jan 2011, J-P Stacey wrote:
The freewheel clutch is gummed up, get some light oil into the
freewheel internals. *

Brilliant, thank you - I will try that tomorrow morning.

Warning: thirty-six is a known bonkerist, and this may be nonsense. It may
well be perfect mechanical truth too.

Is the problem worse in a big or a small sprocket at all? Could the chain
be worn? If you have access to a micrometer or other accurate measuring
device (a tape measure is probably good enough, actually), you could
measure the chain pitch to see if it's stretched. If not, have a look at
how the chain sits on the sprockets along the range (probably easiest to
flip the bike over to do this) - each roller (the bits bridging the
parallel rows of chainplates that make up the linear part of the chain)
should sit nice and kentucky in a pit of the sprocket; if you find that
some of them are riding up out of the pits, that suggests wear.

What a palaver. The information supplied in the original post points
directly to gummed freewheel clutch, the solution is simple. You can
make up alll you want, how about the front gear cable, it could be
rusty or painted blue? Doing a complete bike overhaul might even cure
the problem due to accidental lubricating of the freewheel, but
totally unecessary. Oiling the freewheel from a gummed condition
takes two minutes, and needs doing whether or not there is another
fault. It is one of the simplest and easiest things to do on a bike.
I keep maintenance to a minimum because I have the experience enabling
me to cure little problems without fuss.



I had a worn chain a while ago, displaying those symptoms, and my shifting
trouble only revealed itself after a thorough clean. Perhaps the filthy
grease acts as a sort of adhesive, keeping everything together despite the
wear.

It would have helped if you had paid attention to the reported
problem.

thirty-six wrote:
Warning: thirty-six is a known bonkerist, and this may be nonsense. It may
well be perfect mechanical truth too.


What a palaver. The information supplied in the original post points
directly to gummed freewheel clutch, the solution is simple. You can
make up alll you want, how about the front gear cable, it could be
rusty or painted blue?

What you are forgetting is another piece of information - that his
happened when the chain was taken off and cleaned. Now its possible
that by pure coinicidence, the freewheel clutch chose that exact moment
to gum up. But the overwhelming probability is that its related to the
chain being taken off and on, not the freewheel. Any experienced
engineer will tell you that if something stops working after you've done
some work on something, its most likely to be a consequence of what you
have just done and not an unrelated gremlin.

Tony

On Thu, 27 Jan 2011 07:48:08 +0000
Tony Raven wrote:

What you are forgetting is another piece of information - that his
happened when the chain was taken off and cleaned. Now its possible
that by pure coinicidence, the freewheel clutch chose that exact
moment to gum up. But the overwhelming probability is that its
related to the chain being taken off and on, not the freewheel. Any
experienced engineer will tell you that if something stops working
after you've done some work on something, its most likely to be a
consequence of what you have just done and not an unrelated gremlin.

OP didn't say anything about removing the chain, but did mention
application of sticky goop ...

On Jan 27, 7:48*am, Tony Raven wrote:
thirty-six wrote:
Warning: thirty-six is a known bonkerist, and this may be nonsense. It may
well be perfect mechanical truth too.

What a palaver. *The information supplied in the original post points
directly to gummed freewheel clutch, the solution is simple. *You can
make up alll you want, how about the front gear cable, it could be
rusty or painted blue? *

What you are forgetting is another piece of information - that his
happened when the chain was taken off and cleaned. *

Oh yes, cleaned with a toothbrush and a cloth, never have I heard
someone remove a chain and go at it with a toothbrush and a cloth.
Perhaps you could enlighten us with this gift of knowledge that
enabled you to extract the information that the chain was removed.

Now its possible
that by pure coinicidence, the freewheel clutch chose that exact moment
to gum up. *But the overwhelming probability is that its related to the
chain being taken off and on, not the freewheel. *Any experienced
engineer will tell you that if something stops working after you've done
some work on something, its most likely to be a consequence of what you
have just done and not an unrelated gremlin.

Taking the chain of is unrelated.

Tony Ravin'