Chain off, rear wheel trashed

Peter Grange said:

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?
I shall be emailing the manufacturers with this thought.

I tried fitting an old one after breaking the rear derailleur on my
Speed Machine in a similar incident. The problem was that there simply
wasn't space for it between the biggest sprocket and the spokes. With
the guard fitted, I couldn't actually fit the cassette.

I guess that's the price we pay for having 9-speed cassettes. The guard
originally came off a wheel with a 6-speed block.

--
Danny Colyer (the UK company has been laughed out of my reply address)
<URL:http://www.speedy5.freeserve.co.uk/danny/>
"He who dares not offend cannot be honest." - Thomas Paine

Peter Grange wrote:
.........

Quoted message said:

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?

Bikes in good condition don't need a spoke guard, most expensive bikes
don't come with one.

~PB

In article <[email hidden]>, Pete Biggs <pblackcherry{rem
[email hidden]> writes

Quoted message said:

Bikes in good condition don't need a spoke guard, most expensive bikes
don't come with one.

~PB

Can you further define 'good condition' please?
Why would I pay that kind of money for a bike and then not look after
it?
--
Peter Grange

On Sun, 31 Oct 2004 12:04:27 +0000, Peter Grange wrote:

[snip]

Quoted message said:

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?
I shall be emailing the manufacturers with this thought.

Bike manufacturers have determined that guards are not trendy any more, so
you never see them fitted.
A slight maladjustment and you've ruined your back wheel or derailleur.

--
Mike

in message <[email hidden]>, Peter Grange

(') said:

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?
I shall be emailing the manufacturers with this thought.

Might have something to do with the fact that these 'guards' don't
actually work.

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

;; not so much a refugee from reality, more a bogus
;; asylum seeker

Peter Grange said:

Quoted message said:

Bikes in good condition don't need a spoke guard, most expensive
bikes don't come with one.

Quoted message said:

Can you further define 'good condition' please?

Derailleur adjusted correctly and not broken.

Quoted message said:

Why would I pay that kind of money for a bike and then not look after
it?

Chains don't come off the inside sprocket unless something is damaged or
incorrectly adjusted.

I think there was more of a need for spoke guards in the old days with
cheap derailleurs that worked poorly, and perhaps still now with
kids/beginners. But serious damage doesn't usually result even if
something does go wrong, and usually you can tell that something has
started to go wrong and do something about it.

I never liked them mainly because there's minimal clearance between the
guard and the derailleur, causing rubbing if the guard sightly warps or
comes out of position.

~PB

mb said:

Bike manufacturers have determined that guards are not trendy any
more, so you never see them fitted.

You do see them fitted, to cheap bikes.

Quoted message said:

A slight maladjustment and you've ruined your back wheel or
derailleur.

A slight maladjustment usually results in nothing more than a "tink tink
tink" as the mech just rubs the spokes. You need more than a *slight*
maladjustment or more than a slight bad luck for anything worse to happen.

Fit one if you like but complaining that the manufacturer should have
fitted one is not justified, IMO.

~PB

Simon Brooke said:

Might have something to do with the fact that these 'guards' don't
actually work.

They also look bl**dy awful!

Pete Biggs said:

mb said:

Bike manufacturers have determined that guards are not trendy any
more, so you never see them fitted.

You do see them fitted, to cheap bikes.

I don't think this is a general rule as my cheap bike didn't have one
but my Kona did. Knowing how poorly setup a cheap bike can be it would
seem logical to fit one though where as a more expensive bike would
probably be well set up from the dealer.

Quoted message said:

Quoted message said:

A slight maladjustment and you've ruined your back wheel or
derailleur.

A slight maladjustment usually results in nothing more than a "tink tink
tink" as the mech just rubs the spokes. You need more than a *slight*
maladjustment or more than a slight bad luck for anything worse to happen.

I suppose this varies with the design and dimensions of the wheel.
Some might really crunch if theres not enough space for the wheel to
still go round while the chain has fallen there.

Quoted message said:

Fit one if you like but complaining that the manufacturer should have
fitted one is not justified, IMO.

~PB

A fair point for experienced cyclists who can adjust deraileurs well
but with cheap bikes being almost home assembly and fairly poorly
setup a nice thick and cheap plastic spoke protecter type disc could
eliminate the possibility of this happening altogether. My question is
why are they so large? On my old Raleigh Arena and the Kona the disc
is well above the level of the sprockets by a long way. How would the
chain every get up there?

Martin Wilson said:

.......My question is
why are they so large? On my old Raleigh Arena and the Kona the disc
is well above the level of the sprockets by a long way. How would the
chain every get up there?

The guard is so large to protect the spokes from the derailleur.

~PB

Peter Grange said:

Coming home from yesterday's ride, almost at the front door, changed
down into bottom gear. The chain came off the largest ring on the
cassette & went down between it and the spokes. Much noise, rear wheel
locked, I skidded to a halt (minor note, disengaging from the spd
pedals at last a reaction, no recollection of doing it).

Subsequent examination of wheel shows major bends in two spokes and
damage to the rim where the spokes have pulled on it, in one case
cracking the metal. Can't examine the hub yet, need to get cassette
off.

So, that's at least a new rim and a rebuild.

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?
I shall be emailing the manufacturers with this thought.

They make bikes look like toys. I really shouldn't be possible to derail the
chain in this way especially with modern indexed gears.

In article <[email hidden]>, Pete Biggs <pblackcherry{rem
[email hidden]> writes

Quoted message said:

mb said:

Bike manufacturers have determined that guards are not trendy any
more, so you never see them fitted.

You do see them fitted, to cheap bikes.

How cheap is cheap? My last Dawes Super Galaxy had one.
--
Peter Grange

Peter Grange said:

Can you further define 'good condition' please?

Perhaps "with derailleur screws properly set". I broke the derailleur
on my Street Machine when the chain came off and got caught between the
sprockets and the spokes. It wouldn't have happened if the derailleur
screws had been set properly.

I take full responsibility for that, I couldn't possibly blame the
manufacturer. In my case, I had forgotten to properly finish a
maintenance job.

I suppose I could blame my wife, I might have finished the job properly
if she hadn't gone into labour while I was doing it :-)

--
Danny Colyer (the UK company has been laughed out of my reply address)
<URL:http://www.speedy5.freeserve.co.uk/danny/>
"He who dares not offend cannot be honest." - Thomas Paine

Pete Biggs said:

Martin Wilson said:

.......My question is
why are they so large? On my old Raleigh Arena and the Kona the disc
is well above the level of the sprockets by a long way. How would the
chain every get up there?

The guard is so large to protect the spokes from the derailleur.

~PB

Yeah I thought of that and then I thought that it couldn't actually
help in this regard thinking of the kona as the spokes are obviously
further away. Also if the spoke protector is doing its job and
preventing the chain from getting caught between the
freewheel/cassette and spokes then the derailleur won't be near the
spokes. However with regard much thinner wheels I could see this
having some benefit I suppose. Personally I would have thought a
smaller diameter spoke protecter would be preferable at least for
mountain bikes which are much more likely to get abused anyway and
need such a device.

"Martin Wilson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Yeah I thought of that and then I thought that it couldn't actually
help in this regard thinking of the kona as the spokes are obviously
further away. Also if the spoke protector is doing its job and
preventing the chain from getting caught between the
freewheel/cassette and spokes then the derailleur won't be near the
spokes.

It will if the mech or hanger has been bent. As Pete has said, the only
reasons a mech or a chain go into a wheel are:

1/. The mech or hanger is bent
2/. Component(s) are very worn
3/. The rear mech is out of adjustment

In these circumstances a spoke disc may help you. I've never liked them, but
I have to admit that my reasons are mainly aesthetic. I've never had a wheel
badly damaged by a rear mech going into it, in 200,000 miles of cycling.
(Mind you, a fair number of them were on fixed! ;-) )

Incidentally, I don't know if it's still the case, but Mavic Ksyrium wheels
certainly used to be fitted with (posh but minimalist!) spoke discs - so
they're not *entirely* restricted to entry level!

Pete Biggs said:

mb said:

Bike manufacturers have determined that guards are not trendy any
more, so you never see them fitted.

You do see them fitted, to cheap bikes.

Quoted message said:

A slight maladjustment and you've ruined your back wheel or
derailleur.

A slight maladjustment usually results in nothing more than a "tink tink
tink" as the mech just rubs the spokes.

By the time this happens, the chain could be the wrong side of the last
sprocket...

Quoted message said:

You need more than a *slight* maladjustment or more than a slight bad
luck for anything worse to happen.

"Slight" being a relative term, i.e. enough to cause the chain to go over
the last sprocket

Quoted message said:

Fit one if you like but complaining that the manufacturer should have
fitted one is not justified, IMO.

Yebbut, *I* don't want one and I never complained.

--
Mike

Peter Grange said:

Coming home from yesterday's ride, almost at the front door, changed
down into bottom gear. The chain came off the largest ring on the
cassette & went down between it and the spokes. Much noise, rear wheel
locked, I skidded to a halt (minor note, disengaging from the spd pedals
at last a reaction, no recollection of doing it).

Subsequent examination of wheel shows major bends in two spokes and
damage to the rim where the spokes have pulled on it, in one case
cracking the metal. Can't examine the hub yet, need to get cassette off.

So, that's at least a new rim and a rebuild.

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?
I shall be emailing the manufacturers with this thought.

They look clunky and collect dirt, so few bikes have them these days.
They're completely redundant on a properly-adjusted bike.

On Sun, 31 Oct 2004 12:04:27 +0000, Peter Grange
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Bikes used to have a plastic guard fitted to help prevent this king of
extreme damage did they not? My thought is why should a bike of this
cost (close to ukp2.5k Speed Machine recumbent) not have such a thing
fitted?

Prolly because they didn't work that well, as I recall, and add the
demon mass to your bike. Not that you'd notice it on the average
'bent ;-)

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington University

mb said:

Quoted message said:

Quoted message said:

A slight maladjustment and you've ruined your back wheel or
derailleur.

A slight maladjustment usually results in nothing more than a "tink
tink tink" as the mech just rubs the spokes.

By the time this happens, the chain could be the wrong side of the
last sprocket...

The derailleur usually contacts the spokes *before* the chain comes off,
if it ever does.

Quoted message said:

Quoted message said:

You need more than a *slight* maladjustment or more than a slight bad
luck for anything worse to happen.

"Slight" being a relative term, i.e. enough to cause the chain to go
over the last sprocket

I call that a lot more than slight.

Quoted message said:

Quoted message said:

Fit one if you like but complaining that the manufacturer should have
fitted one is not justified, IMO.

Yebbut, *I* don't want one and I never complained.

"You" doesn't have to mean you :-)

~PB