Freehub problem
Dan Daniel
used a few months ago, the chain and cassette were pretty new while
the chainrings were pretty worn. The rear cones were pitted and I
replaced them along with the chainrings.
Problems- when I do any backpedaling in the four smaller rear cogs,
the chain does not always flow cleanly backwards. The chain goes slack
between the top of the chainring and the top of the freehub. It will
eventually go backwards, and usually before all the take-up in the
rear derailleur is gone. As if there is heavy jelly in the freehub
mechanism.
Rarely, I get a jump in the drivetrain. My best guess is that it is a
problem with the freehub pawls. Always at applying initial pressure,
either when starting after a stop or after coasting.
I have removed and flushed the freehub three times now. The first time
I put Phil Wood tenacious oil in it. Didn't help- flush, then Tri Flo.
Didn't help- flush, then Prolink. The freehub spins nicely, no gritty
feel, etc.
Today it was colder than it has been in a while (50 F) and the
backpedal problem was much worse than when warmer.
Is it possible that the grease on the right side is affecting the
freehub? I can see that the cup area doesn't completely seal off the
freehub body from the grease. Too much grease creating drag on the
freehub body? I am using TriFlo grease.
Or does this sound like a shot freehub body?
Or should I be looking at other things?
Thanks.
jobst....@stanfordalumni.org
> Shimano Deore LX rear hub, FH-M563 7 speed. When I bought the
> bicycle used a few months ago, the chain and cassette were pretty
> new while the chainrings were pretty worn. The rear cones were
> pitted and I replaced them along with the chainrings.
> Problems- when I do any backpedaling in the four smaller rear cogs,
> the chain does not always flow cleanly backwards. The chain goes
> slack between the top of the chainring and the top of the
> Freehub. It will eventually go backwards, and usually before all the
> take-up in the rear derailleur is gone. As if there is heavy jelly
> in the Freehub mechanism.
Take our wheel out and see how easily the gear cluster spins backward.
No need to guess what is causing the bind. If it's not that, then the
chain angle is to severe to engage. Could it be that you are doing
this from other than the right most chainwheel? That presents an
engagement problem all by itself.
> Rarely, I get a jump in the drivetrain. My best guess is that it is
> a problem with the Freehub pawls. Always at applying initial
> pressure, either when starting after a stop or after coasting.
Take it off the bicycle and see what it's doing by hand. This is a
pretty straight forward test. You should be able to disassemble the
Freehub, clean and re-lubricate it.
> I have removed and flushed the free hub three times now. The first
> time I put Phil Wood tenacious oil in it. Didn't help- flush, then
> TriFlow. Didn't help- flush, then Prolink. The Freehub spins
> nicely, no gritty feel, etc.
Use nothing heavier than 30W motor oil, preferable 10W in colder
weather. When you reverse rotation by hand, can you get it to skip a
tooth? I think if you opened it, you would find a damaged pawl.
> Today it was colder than it has been in a while (50 F) and the
> backpedal problem was much worse than when warmer.
That isn't cold yet. If it gets below freezing, it might no work at
all. Stop using tenacious lubricants. That's exactly what you don't
need.
> Is it possible that the grease on the right side is affecting the
> Freehub? I can see that the cup area doesn't completely seal off
> the Freehub body from the grease. Too much grease creating drag on
> the Freehub body? I am using TriFlow grease.
> Or does this sound like a shot Freehub body?
From what you say, you seem to have found the cause in the Freehub.
Take it apart and see what isn't working.
Jobst Brandt
jobst....@stanfordalumni.org
Phil, Squid-in-Training
> all. Stop using tenacious lubricants. That's exactly what you don't
> need.
This lube situation... are you saying that you can overlube the freehub?
--
Phil, Squid-in-Training
Dan Daniel
<philMuN...@hahtmail.com> wrote:
>> That isn't cold yet. If it gets below freezing, it might no work at
>> all. Stop using tenacious lubricants. That's exactly what you don't
>> need.
>
>This lube situation... are you saying that you can overlube the freehub?
I read him as referring to me using Phil's Tenacious Oil. Meaning
something like a 90 weight gear oil. Too heavy to allow rapid movement
of the pawls on their pivot points, maybe?
Beyond that, I do wonder how much lube a freehub/wheel does need.
Thinking about it, seems that it is under minimal pressure when
freewheeling and the bearings are in action, and the bearings are not
in use when it is under load. Unlike, say, hub bearings.
In high school, we used to open up freewheel bodies and put grease in
the pawl area to shut up that stupid clatter when touring. And the
only problem we ever had was someone's top ring coming off going up a
hill. Nothing like trying to find those little bearings along the
roadside so that we could stuff enough back in to get him going again.
I wonder if the size and springs in larger freewheel bodies made it
possible to gum up the pawls with grease. Or we were just lucky.
jobst....@stanfordalumni.org
>> That isn't cold yet. If it gets below freezing, it might no work
>> at all. Stop using tenacious lubricants. That's exactly what you
>> don't need.
> This lube situation... are you saying that you can overlube the
> freehub?
Amount of lubricant does not change with season or temperature but
when cold, more viscous oils become solid and prevent pawl engagement.
"Tenacious" implies higher viscosity although the term does not appear
in lubrication journals so it remains an advertising gimmick at best.
Jobst Brandt
jobst....@stanfordalumni.org
Qui si parla Campagnolo
something like a 90 weight gear oil. Too heavy to allow rapid movement
Use Mobil One-like 5w-20 or somesuch. lasts forever, doesn't get thick. As for
Jobst recommending taking the freehub apart and clean/lube/reassemble, perhaps
a little above the OP skills, as it is above most LBS wrench's skills???
Better to take it off, flush well, and lube with Mobil 1.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
Dan Daniel
Campagnolo) wrote:
>Some-<< I read him as referring to me using Phil's Tenacious Oil. Meaning
>something like a 90 weight gear oil. Too heavy to allow rapid movement
>of the pawls on their pivot points, maybe? >><BR><BR>
>
>Use Mobil One-like 5w-20 or somesuch. lasts forever, doesn't get thick. As for
>Jobst recommending taking the freehub apart and clean/lube/reassemble, perhaps
>a little above the OP skills, as it is above most LBS wrench's skills???
>
Now, now, not above my skills :) Above my access to the specific
tool, and above my desire to buy or fabricate the tool or jury rig
another method, and mainly far above my desire to spend such time to
rebuild a part that isn't worth the effort. If you know a source for
replacement pawls and springs for a 1996 +/- LX 7-speed freehub, I'll
give it more consideration :)
>Better to take it off, flush well, and lube with Mobil 1.
>
One more go-round and then I'll consider the freehub shot. At which
point I probably will open it up for the laughs. I was wondering if
there was some other place to look other than the obvious freehub
internals, but seems not.
Thanks to everyone for the comments.
A Muzi
-snip-
> Problems- when I do any backpedaling in the four smaller rear cogs,
> the chain does not always flow cleanly backwards. The chain goes slack
> between the top of the chainring and the top of the freehub.
> Rarely, I get a jump in the drivetrain. My best guess is that it is a
> problem with the freehub pawls. Always at applying initial pressure,
> either when starting after a stop or after coasting.
> Is it possible that the grease on the right side is affecting the
> freehub?
That's possible I suppose but isn't common. Another likely
scenario is right side dust shell drag - those are really
hard to remove/reinstall without damage and a dented one
would drag as you describe.
But the no-coast phenomenon, while annoying, is not as
serious as the pawl dysfunction. Definitely get that fixed,
which is cheaply done by grabbing a replacement body from a
scrap wheel.
Even if you have to _buy_ a new body, do it. The thought of
a pawl failure while standing through a yellow light should
be enough to convince you of the severity.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
Qui si parla Campagnolo
Not trying to get personal, but most LBS wrenches don't know how to do this. No
small parts either offered by shimano. A take off, dead for another reason
freehub is the only source for parts.
Thbis freehub complete is easy to get, about $30.
Dan Daniel
wrote:
>
>Even if you have to _buy_ a new body, do it. The thought of
>a pawl failure while standing through a yellow light should
>be enough to convince you of the severity.
Ack! Painful painful scenario. You've convincd me.
ant
> tool, and above my desire to buy or fabricate the tool or jury rig
> another method, and mainly far above my desire to spend such time to
> rebuild a part that isn't worth the effort.
oh, but its fun. and i got the tool for eight dollars, IIRC, and have
revived a couple freehubs with it, so i figure it was a good
investment.
If you know a source for
> replacement pawls and springs for a 1996 +/- LX 7-speed freehub, I'll
> give it more consideration :)
>
id lean a lot harder towards getting an old freehub from an abandoned
POS hub lying around most LBSs than looking for individual freehub
parts.
Dan Daniel
Curious- are the pawls and springs interchangeable from model to
model? Would I need a 7-speed LX freehub to take apart for
replacements? Any 7-speed? Any Shimano freehub at all? What have you
found out?
ant
> model? Would I need a 7-speed LX freehub to take apart for
> replacements? Any 7-speed? Any Shimano freehub at all? What have you
> found out?
what have i found out? nothing, really. i havent taken apart enough
freehubs to notice , let alone remember, any trends. i think the only
two ive done surgery on that were the same were two shitty seized up
ritchey bodies.
but are you really thinking of overhauling a freehub? if youre
thinking of doing it for fun, then go ahead and do it. take it apart,
clean everything really well, maybe a little steel wool if the pawls
are rusted up, and possibly some new bearings, generally a little over
50 1/8". but if youre talking about actually replacing parts, you
might as well get a whole new (or used, but working) freehub. take
that apart too, if you want, but i woudl venture to guess that its not
worth the time to find individual parts to tgrade between bodies.
freehub bodies dont seem to be very technologically advanced, in the
low to mid range. i think any old thing lying around would generally
work.
campy sells individual parts. i've special ordered pawl springs and
pawls for hardcore customers. but shimano? the shop i work at has a
bucket of some 50 old hubs cut out of wrecked wheels. ill bet a lot of
other shops have that same bucket lying around somewhere, and they
might be pleased to let a freehub join a new home for minimal cash and
minimal logistical worry.
but to answer your question.. no, i have no idea what is
interchangeable ;)
cheers,
anthony