Slipping freewheel?

Colin Blackburn said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear
wheel. It felt as if the gears were shifting up a cog, but they
weren't. The feeling was as if the cranks turned for a fraction without
pulling the bike. There was a thought that there was a problem with the
freewheel, maybe even the cranks. It went away after a while and I did
the rest of the 80km without incident. Cycling in this morning I had
the same problem, again it started after a few miles but went away
after a few minutes and there was no problem for the bulk of the journey.

Any idea where I should start looking and how I could isolate the problem?

If it were the cranks, it would be really obvious and probably wouldn't
go away.

Chances are, it was some grit preventing one of the freewheel pawls
(like a ratchet) engaging. If it recurs, and if it's a removeable
freewheel (as opposed to a cassette/freehub), try giving it a good soak
in paraffin and re-lubing.

--
Mark.

Colin Blackburn typed:

Quoted message said:

At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike.

I've had this a couple of times ... Once it was a freewheel so clogged up
with mud, dirt and accumulated crud that the inner pawls that engage to turn
the wheel simply couldn't move. Cured by removing freewheel assembly,
dis-assembling it, cleaning and replacing everything. Please note, there
are a [censored]-load of bits and pieces in a freewheel ... I'd recommend not
dis-assembing it, but use a de-greaser spray, and lubricant .. or buy
another freewheel system .. 😉

Second time it was a tyre rotating on the rim .. very low pressures, trying
to get home, knowing it was low .. 😉 I doubt this would be your problem.

--
Paul ...

(8(|) ... Homer Rocks

Mark Tranchant said:

Colin Blackburn said:

Any idea where I should start looking and how I could isolate the
problem?

If it were the cranks, it would be really obvious and probably wouldn't
go away.

Yes, I thought that. The 'feel' isn't at the pedals.

Quoted message said:

Chances are, it was some grit preventing one of the freewheel pawls
(like a ratchet) engaging. If it recurs, and if it's a removeable
freewheel (as opposed to a cassette/freehub), try giving it a good soak
in paraffin and re-lubing.

I'd better check exactly what it is. But, thanks.

Colin

in message <[email hidden]>, Colin Blackburn

(') said:

At the weekend I used my MTB for this race that I've been chuntering
on about. At one point, a few miles in, I had a slipping on the rear
wheel. It felt as if the gears were shifting up a cog, but they
weren't. The feeling was as if the cranks turned for a fraction
without pulling the bike. There was a thought that there was a problem
with the freewheel, maybe even the cranks. It went away after a while
and I did the rest of the 80km without incident. Cycling in this
morning I had the same problem, again it started after a few miles but
went away after a few minutes and there was no problem for the bulk of
the journey.

Any idea where I should start looking and how I could isolate the
problem?

Could the chain be riding over the teeth for a moment? This can happen
with very worn cogs or with a misadjusted rear deraileur.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

For office use only. Please do not write or type below this line.

"Colin Blackburn" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike. There was a thought that there was a problem with the freewheel,
maybe even the cranks. It went away after a while and I did the rest of
the 80km without incident. Cycling in this morning I had the same problem,
again it started after a few miles but went away after a few minutes and
there was no problem for the bulk of the journey.

Any idea where I should start looking and how I could isolate the problem?

Sounds a bit like a slipping chain.

I have this problem because I went too long without renewing my chain.

Now I have a new chain and slipping on the smallest cogs on the rear gear
cluster on the freewheel.

Awaiting new gear cluster :-(

Is your chain, perhaps, stiff?

If so it might give 'new chain, old cogs' syndrome for a few miles until it
loosened up.

HTH
Dave R

On Mon, 26 Jul 2004 12:28:17 +0100, David W.E. Roberts <[email hidden]>

Quoted message said:

Is your chain, perhaps, stiff?

If so it might give 'new chain, old cogs' syndrome for a few miles until
it
loosened up.

Thanks to all so far. Plenty to think about. It's worth adding that the
bike is relatively new so the cogs aren't worn and the chain is new. It
had had a couple of semi-rough 30 mile rides under its tyres before the
anything started happening.

Colin

Colin Blackburn said:

At the weekend I used my MTB for this race that I've been chuntering
on about. At one point, a few miles in, I had a slipping on the rear
wheel. It felt as if the gears were shifting up a cog, but they
weren't. The feeling was as if the cranks turned for a fraction
without pulling the bike. There was a thought that there was a
problem with the freewheel, maybe even the cranks. It went away after
a while and I did the rest of the 80km without incident. Cycling in
this morning I had the same problem, again it started after a few
miles but went away after a few minutes and there was no problem for
the bulk of the journey.

Sounds like worn or mismatched chain & sprockets but I would first check
the chain for stiff links. Perhaps one link is just stiff enough to cause
the occasional problem. Could be the freewheel but the slips last for
more than a second if it's gunked up, in my experience, and feel smooth
rather than violent skips.

Also check the gear cable is okay: there's a chance the gear could have
semi-changed for a fraction then changed back again.

~PB

quote='Pete Biggs'Colin Blackburn said:

At the weekend I used my MTB for this race that I've been chuntering
on about. At one point, a few miles in, I had a slipping on the rear
wheel. It felt as if the gears were shifting up a cog, but they
weren't. The feeling was as if the cranks turned for a fraction
without pulling the bike. There was a thought that there was a
problem with the freewheel, maybe even the cranks. It went away after
a while and I did the rest of the 80km without incident. Cycling in
this morning I had the same problem, again it started after a few
miles but went away after a few minutes and there was no problem for
the bulk of the journey.

Sounds like worn or mismatched chain & sprockets but I would first check
the chain for stiff links. Perhaps one link is just stiff enough to cause
the occasional problem. Could be the freewheel but the slips last for
more than a second if it's gunked up, in my experience, and feel smooth
rather than violent skips.

Also check the gear cable is okay: there's a chance the gear could have
semi-changed for a fraction then changed back again.

~PB[/QUOTE]

If the gear cable passes under the BB shell, check that is is running smoothly in its guide. Maybe it had jumped out of its guide some how thus moving the derailleur to be in the wrong place and causing the 'slipping'.

"Colin Blackburn" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike. There was a thought that there was a problem with the freewheel,
maybe even the cranks. It went away after a while and I did the rest of
the 80km without incident.

sounds pretty much like what happens as the chain/cassete sprockets
wear and the chain starts spotaneously jumping about. As to how to
eliminate this or any other candidates (apart from swapping out chain
and cassette) I am less sure

best wishes
james

In article <[email hidden]>, Simon

Brooke said:

Quoted message said:

Any idea where I should start looking and how I could isolate the
problem?

Quoted message said:

Could the chain be riding over the teeth for a moment? This can
happen with very worn cogs or with a misadjusted rear deraileur.

If it only happens in the highest gear/smallest sprocket at the rear
it is probable that you need a new freewheel.

--
A T (Sandy) Morton
on the Bicycle Island
In the Global Village
http://www.millport.net

In article <[email hidden]>, Colin Blackburn

Quoted message said:

Thanks to all so far. Plenty to think about. It's worth adding that
the bike is relatively new so the cogs aren't worn and the chain is
new. It had had a couple of semi-rough 30 mile rides under its
tyres before the anything started happening.

In which case it will help the diagnosis if you turn the pedals
gently backwards and watch the chain for stiff links.

--
A T (Sandy) Morton
on the Bicycle Island
In the Global Village
http://www.millport.net

[email hidden] (james) wrote in message news:<[email hidden]>...

Quoted message said:

"Colin Blackburn" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike. There was a thought that there was a problem with the freewheel,
maybe even the cranks. It went away after a while and I did the rest of
the 80km without incident.

I had similar prob - sudden disengagment of freewheel, pedals turning
but no power. It turned out to be over enthusiastic application of
grease to the free wheel (old sort whatever you call them, not a
cassette). The pawls eventually being stuck in and not engaging. Had
to dismantle it completely and clean grease off, and not loose
hundreds of small ball bearings and several tiny springs. Did this in
Portugal in pouring rain in muddy field surrounded by bemused
portuguese cherry pickers who would have helped if they could - very
nice people the portuguese, excellent place for cycle touring.
Would not have been able to do it with a cassette - lot to be said for
older technology in terms of maintenance when you are desperate and
far from home.
So - no grease, only thin bike oil.
How do you spell 'loose', 'lose'? rhymes with booze?

cheers

Jacob

jacob [email hidden] opined the following...

Quoted message said:

How do you spell 'loose', 'lose'? rhymes with booze?

Lose. You will lose the ball bearings if you are not careful because
they are often loose.

He he

Jon

Sandy Morton said:

In article <[email hidden]>, Colin Blackburn

Quoted message said:

Thanks to all so far. Plenty to think about. It's worth adding that
the bike is relatively new so the cogs aren't worn and the chain is
new. It had had a couple of semi-rough 30 mile rides under its
tyres before the anything started happening.

In which case it will help the diagnosis if you turn the pedals
gently backwards and watch the chain for stiff links.

I've (after between 500-1000 miles) discovered (or I think I have) the
cause of the noise on some sprockets, and hopefully the cause of the
annoying 'chain leaps off chainwheel with gleefull abandon' incidents.

It sounded like a stiff link, but I couldn't find one anywhere.

Then I cleaned the chain, and in doing so, realised something was odd
abotu one of the links.

It was bent!

And it was also the link that has the joining pin - so my guess is it's
very unlikely jumping off the chainrings managed to dent the same one
that joins the chain, and that the link has *always* been bent since it
was put on by the manufacturer...

I have new chain, tool, and pins, and am hoping this weekend to swap it
for the one that's on there and see if it cures the problem (adjusting
the shifting just mucked up the gears no matter how carefully I did it)
- and hopefully I won't be looking at a new casette through it having
worn two of the sprockets (the noisy ones)... be bloody annoyed if I am!

--

Velvet

"Colin Blackburn" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike. There was a thought that there was a problem with the freewheel,
maybe even the cranks. It went away after a while and I did the rest of
the 80km without incident. Cycling in this morning I had the same problem,
again it started after a few miles but went away after a few minutes and
there was no problem for the bulk of the journey.

Any idea where I should start looking and how I could isolate the problem?

Colin

I've had a similar problem several times on my C'dale which is ridden
on road and off-road just enough to put off racers, not enough to get
the mtb brigade out of bed. Symptom (always same): pedalling along,
suddenly the drive "disengages" as if making a very long gear change
or the chain has come off, the pedals continue turning but there is no
resistance. Drive then reengages after a couple of resolutions of the
pedals and all is as before. Once it has occurred, the problem
recurrs with increasing frequency until the drive fails to reengage
:-(.

The cause has been diagnosed by LBS as either loose or worn out hub
body in the rear wheel. Replacement cost <£20 inc labour (Cambridge
prices), tightening cost a flutter of eyelashes.

I have had this problem and told the mechanics what I wanted done,
because it was the same as before, only to be told that the bike
should be making one hell of a racket if that were the case. When
they've looked at it in the workshop, the hub body has been
practically worn out afterall. It might be worth stripping down your
hub to see, assuming you have the skills and tools.

I have been led to believe that my past lacksdaisical attitude to
cleaning has caused the problem. Now I am converted to the joys of
degreaser etc, I wait to see if the problem recurs.

Clear skies
Sarennah

"Colin Blackburn" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

At the weekend I used my MTB for this race that I've been chuntering on
about. At one point, a few miles in, I had a slipping on the rear wheel.
It felt as if the gears were shifting up a cog, but they weren't. The
feeling was as if the cranks turned for a fraction without pulling the
bike. There was a thought that there was a problem with the freewheel,
maybe even the cranks. It went away after a while and I did the rest of
the 80km without incident. Cycling in this morning I had the same problem,
again it started after a few miles but went away after a few minutes and
there was no problem for the bulk of the journey.

Any idea where I should start looking and how I could isolate the problem?

Colin

I've had a similar problem several times on my C'dale which is ridden
on road and off-road just enough to put off racers, not enough to get
the mtb brigade out of bed. Symptom (always same): pedalling along,
suddenly the drive "disengages" as if making a very long gear change
or the chain has come off, the pedals continue turning but there is no
resistance. Drive then reengages after a couple of resolutions of the
pedals and all is as before. Once it has occurred, the problem
recurrs with increasing frequency until the drive fails to reengage
:-(.

The cause has been diagnosed by LBS as either loose or worn out hub
body in the rear wheel. Replacement cost <£20 inc labour (Cambridge
prices), tightening cost a flutter of eyelashes.

I have had this problem and told the mechanics what I wanted done,
because it was the same as before, only to be told that the bike
should be making one hell of a racket if that were the case. When
they've looked at it in the workshop, the hub body has been
practically worn out afterall. It might be worth stripping down your
hub to see, assuming you have the skills and tools.

I have been led to believe that my past lacksdaisical attitude to
cleaning has caused the problem. Now I am converted to the joys of
degreaser etc, I wait to see if the problem recurs.

Clear skies
Sarennah