o-ring chain
jim beam
o-ring chain for bicycles?
they're used for off-road motorcycles with great success in reducing
chain wear, so it would be logical for that to extend to human powered
machines. anyone know if that's happened yet, and is so, do you have a
source?
jb
Dave Thompson
"jim beam" <u...@ftc.gov> wrote in message
news:gJTwb.346$i%6....@newssvr27.news.prodigy.com...
bicycles for the following reasons: too expensive for what is returned in
the way of minimized chain wear and, more importantly, much greater friction
losses in the chain.
Werehatrack
said:
Where would you remove material from existing chain designs to insert
a durable and sufficiently elastic set of O-rings? The side plates
are too thin, the roller is too narrow, and the chain must have more
lateral flexibility than could be sealed by any o-ring that would be
possible to include. There's just no place to put a pair (or quartet)
of o-rings that would be able to seal the roller and the pin of a
bicycle chain.
--
My email address is antispammed; pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
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Words processed in a facility that contains nuts.
jim beam
> a durable and sufficiently elastic set of O-rings? The side plates
> are too thin, the roller is too narrow, and the chain must have more
> lateral flexibility than could be sealed by any o-ring that would be
> possible to include. There's just no place to put a pair (or quartet)
> of o-rings that would be able to seal the roller and the pin of a
> bicycle chain.
hmm, interesting points, but i think they are surmountable - it's just a
question of scale - the technology would be the same as motorcycle
chain. and regarding friction as mentioned by dave, i think this would
be a small price to pay for a chain that does not self destruct in mud.
i had a couple of rides last winter where both i and my bike were
completely caked. the grinding from the chain in the last few miles was
hideous, and it was starting to regularly foul itself because the
rollers were starting to stick. i'm sure there are people out there
like myself that would pay a little extra for reliability.
jb
Eric M
I don't think it'll happen soon. Besides having noticeably
greater friction, at least when cold, they are also significantly wider
than standard non-O-ring chains.
Most enduro riders (think century/long road race) use 0-ring chains,
moto-cross (criterium) racers and trials (trials!) riders use non O-ring
chains.
Eric
Carl Fogel
Dear Jim,
I think that Werehatrack's point, however, is that it
isn't entirely a question of scale.
Motorcycle chains have a wonderful straight chainline
from a single front countershaft sprocket to a single
rear drive sprocket. The idea of a chain mis-aligned
to one side is as difficult for a motorcyclist to
conceive as . . . see ludicrously irrelevant quote
from the Devil's Dictionary.
Anyway, bicycle chains lash from side to side like
alligator tails, criss-crossing between various front
and rear gears. This extra sideways or lateral bending
would tend to open things up beyond the closing ability
of motorcycle-style O-rings, letting in all the mud
that annoys the off-road bicycle in the first place.
In any case, the market for such expensively miniaturized
chains is likely to be so small that it would not be the
small price that you hope to pay.
Carl Fogel
A mis-aligned chain is as difficult for motorcyclists to
conceive as . . .
TIGHTS, n. An habiliment of the stage designed to reinforce
the general acclamation of the press agent with a particular
publicity. Public attention was once somewhat diverted from
this garment to Miss Lillian Russell's refusal to wear it, and
many were the conjectures as to her motive, the guess of Miss
Pauline Hall showing a high order of ingenuity and sustained
reflection. It was Miss Hall's belief that nature had not
endowed Miss Russell with beautiful legs. This theory was
impossible of acceptance by the male understanding, but the
conception of a faulty female leg was of so prodigious originality
as to rank among the most brilliant feats of philosophical
speculation!
S. Anderson
news:bq33mc$rns$1...@slack.lne.com...
>
> I don't think it'll happen soon. Besides having noticeably
> greater friction, at least when cold, they are also significantly wider
> than standard non-O-ring chains.
>
>
> Most enduro riders (think century/long road race) use 0-ring chains,
> moto-cross (criterium) racers and trials (trials!) riders use non O-ring
> chains.
>
> Eric
And most road race guys convert from a 530 O-ring chain to a 520 non-O-ring
for less friction and weight. A 520 chain is about 3/4 the width of a 530.
Every little bit helps I suppose.
Cheers,
Scott..
Jim Adney
>since we seem to be in "product testing" mode, has anyone heard of
>o-ring chain for bicycles?
I don't think the manufacturers think it's practical for drive chain
as small as that used on bicycles. It's only offered in the larger
sizes of drive chain.
-
-----------------------------------------------
Jim Adney jad...@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Mike DeMicco
"Dave Thompson" <davets...@comcast.net> wrote:
> I think O-ring chains, as practiced on motorcycles, wouldn't benefit
> bicycles for the following reasons: too expensive for what is returned in
> the way of minimized chain wear and, more importantly, much greater friction
> losses in the chain.
Well, I would disagree with that. The chain is the highest maintenance
item on a bicycle (other than having to air up tires, that is). I would
be nice not having to clean and lube the thing so often.
Since no one has come up with an o-ring sealed chain for a bike, I don't
think you can claim that it has much greater friction losses -
especially when compared with a dirty chain.
--
Mike DeMicco <blaster186...@comcast.net>
(Remove the REMOVE_THIS from my email address to reply.)
Werehatrack
have said:
>On Wed, 26 Nov 2003 01:54:20 GMT jim beam <u...@ftc.gov> wrote:
>
>>since we seem to be in "product testing" mode, has anyone heard of
>>o-ring chain for bicycles?
>
>I don't think the manufacturers think it's practical for drive chain
>as small as that used on bicycles. It's only offered in the larger
>sizes of drive chain.
Correct.
A bike chain's links must accomodate flex. This flexure is only
possible to achieve by permitting the links to have some inherent slop
in them that allows the pins to run at an angle. To seal something
with an o-ring, the ring must be under compression against the inner
and outer surfaces of contact. In a bike chain, then, to remain
sealed when the pin deflects, the ring would have to be precompressed
by an amount greater than the radial relaxation caused when the
deflection is in the direction of opening the joint, and would have to
have sufficient remaining compressibility to allow the ring to crush
on the opposite side at the same time, and would have to do this
without measurably changing the deflection force characteristics of
the chain. Realistically, there is no o-ring material which has any
chance whatever of meeting this requirement.
jim beam
> chance whatever of meeting this requirement.
not trying to be rude, but that sounds very negative. there are all
kinds of bearing seals that accomodate varying degrees of movement.
maybe "o-ring" is a misleading. let's try "sealed" instead. i can't
see that it would be difficult.
jb
Werehatrack
said:
> > Realistically, there is no o-ring material which has any
>> chance whatever of meeting this requirement.
>
>not trying to be rude, but that sounds very negative. there are all
>kinds of bearing seals that accomodate varying degrees of movement.
Yes. I've used many of them, and have had to locate substitute seals
for items that were obsolete on a number of occasions; most shaft
seals are designed to operate in a situation where the motions do not
include any significant radial component. When there is such motion
present, it's generally due to the shaft being so heavily loaded that
it's flexing, and it still amounts to just a small fraction of the
seal's cross-section. The normal running alignment variation in a
bike chain is very large by comparison.
>maybe "o-ring" is a misleading. let's try "sealed" instead. i can't
>see that it would be difficult.
O-rings or X-rings (or variations on that theme) are what's used in
existing sealed chains, with good reason. That's what is possible to
fit in there...and those chains are *much* wider than a bike chain.
Look at this:
http://www.drivesinc.com/roller-PDFs/rollr-preimp2.pdf
Note that the roller in such chains is still not sealed.
Or consider this:
http://www.rk-excel.co.jp/english/tech/chain_spec_200209.pdf
Note that in each case, the sealed chain is wider than its unsealed
counterpart. Since on 8, 9 and 10-speed cassettes, there's just no
room for a wider chain, the addition of the sealing components cannot
be accomplished in this manner.
Now look at the space between the plates of a bike chain. Look at the
thickness of those plates. Remember that to add space for the seal
between the plates, those plates must become thinner...and they're
already about as thin as it is practical to make them.
Perhaps a V-section ring might be possible to put between the plates
with just a small reduction in plate thickness, but it would have to
be incredibly thin and thereby much too fragile, and this still does
nothing about the dirt which gets in under the roller. To add a pair
of sealing rings in that location, you're forced to decrease the
contact face area on the roller and side plate flanges to provide room
for the rings there...and the same alignment issues still pertain,
with the same set of problems.
No, this is a dead end. Bike chains are not like motocycle chains,
where straight-line runs are the rule. Bicycle chains have too much
side flex, and too little room for anything to be inserted.
Mike DeMicco
news:mn3osvk7sm60nj8je...@4ax.com:
> Now look at the space between the plates of a bike chain. Look at the
> thickness of those plates. Remember that to add space for the seal
> between the plates, those plates must become thinner...and they're
> already about as thin as it is practical to make them.
If you use an internal hub geared system instead of derailleur gears, the
chain can be wider.
Werehatrack
<blaster186...@comcast.net> may have said:
Limit with current tech: 14 speeds. (Which, admittedly, is far more
than the casual rider really needs.)
Drawbacks: heavy and expensive.
However, in my personal opinion, the geared hubs look very attractive
in many respects. If a sealed chain were available to use with them,
this would be a good low-maintenance solution.
It should be remembered, however, that even sealed chains still
require some external lube, and periodic cleaning. A toothed belt
drive and a geared hub would eliminate that mess.
Ted Bennett
> >If you use an internal hub geared system instead of derailleur gears, the
> >chain can be wider.
>
> Limit with current tech: 14 speeds. (Which, admittedly, is far more
> than the casual rider really needs.)
No, it's 28 speeds using the Schlumpf planetary geared crankset
(ignoring the duplication which may be present).
Your gripes about cost and weight apply to this setup of course. But
the clean appearance of the no-derailer system is attractive. The
traditional beef about efficiency is certainly arguable as it would be
easier to implement a straight run of O-ring chain.
Or a well sealed chainguard, but there goes the clean appearance bit.
--
Ted Bennett
Portland OR
Werehatrack
<tedbe...@earthlink.net> may have said:
>Werehatrack <rau...@earthWEEDSlink.net> wrote:
>
>> >If you use an internal hub geared system instead of derailleur gears, the
>> >chain can be wider.
>>
>> Limit with current tech: 14 speeds. (Which, admittedly, is far more
>> than the casual rider really needs.)
>
>No, it's 28 speeds using the Schlumpf planetary geared crankset
>(ignoring the duplication which may be present).
There might be some duplications or near-same ratios, but this is true
for derailleur setups too, so 28 would be a valid statement.
>Your gripes about cost and weight apply to this setup of course.
Yet another candidate for the Understatement of the Week, at least as
far as cost. The weight factor on the Schlumpf, as I understand it,
isn't as serious as for the 14-speed hub, though.
>But
>the clean appearance of the no-derailer system is attractive.
Very true! So is the added chain and sprocket durability from the
wider single-speed chain.
>The
>traditional beef about efficiency is certainly arguable as it would be
>easier to implement a straight run of O-ring chain.
There are always trade-offs. I have no doubt that derailleurs are
more popular than gearhubs for the overall market because they're much
cheaper per gear provided, but they dominate the racing market because
they're more efficient and lighter. If the gearhubs were the same
weight and had the same drive losses as derailleurs, I have no doubt
that they would be the system of choice for competition.
>Or a well sealed chainguard, but there goes the clean appearance bit.
Actually, some people might like the sealed-chainguard look right now.
It's the retro thing. Times will change yet again, and it's hard to
say what the next trend will be. (It's been fun seeing the late-60s
miniskirts back in action, though.)