Fixed/free hub opts to be free/free

"Paul Hobson" wrote in message
...
Tom Nakashima wrote:

I once bet my friend that a fixedgear couldn't freewheel. He also rides
without a lockring and he actually unthreaded the cog by standing on the
pedals, then quickly forward pedaled retheading the cog before it came
off. Guess I lost the bet because I didn't state how long of a freewheel.
btw; I ride with a lockring, but only secure it just past finger tight.
-tom

That's how I started with my lockring/sprocket, but noticed that strong
back pedaling unthreaded the cog just slightly, which really threw off my
mojo. So as per some advice of Mr. Sheldon, I road up a really stiff hill
with some tools in my pocket to really thread the sprocket on tight. At
the top of the hill I took off the wheel and then really torqued down the
lockring ring hard. I've only felt the sprocket slip a little bit a
couple time while skidding (something I *hate* doing).

Can you friend who rides sans lockring do track stands when the hill
slopes downward?

\\paul
www.fastermustache.org

My friend is a lot heavier than I, and has a lot of power in his legs. I'm
really not sure why he doesn't use an inexpensive lock ring since he can
also ride his fixie backwards, or at least do a figure 8 backwards. We both
can do track stands, but it's a balance thing. I not sure if the track
stand you're referring to is making a skid...that I can't do, but my friend
will sometimes leave his mark. My fixie is a converted steel frame bike.
It has a longish wheelbase and a relaxed rake both headtube and seat-tube,
so there is no toe-overlap which makes the wheelstand a lot easier on
red-lights.

Yes, Sheldon has great cycling information. In his website, I picked up a
lot of good advice on fixedgear riding.
-tom

"Luke" wrote in message
...
In article , Tom Nakashima
wrote:

"Luke" wrote in message
...

More exactly, that the outcome wouldn't have been different; but I
concede your point. I was reasoning (Disclaimer: I'm not an engineer) -
along these lines: once the chain jammed and began leveraging the cog
off with the force of the bike's momentum behind it, the dynamic at
play was essentially a battle of strength between the hub's cog and
lockring threaded portions? And wouldn't the cog's greater surface area
of thread engagement over the lockring's (one installed to spec), favor
the hub's cog threads at the expense of its lockring grooves?
Luke

How did your chain get jammed?

snip

Well I was preoccupied with other matters during the duration of the
snafu ;-) and so could only surmise the specifics post facto, with the
bike roadside, its cog unscrewed and chain swinging freely from the BB
shell and wheel's axle.

But based on observations from previous - and more innocuous! -
derailments and details particular to the event, I've a fair idea. Bear
in mind the time span from the chain's derailment and cog unscrewing
was little more than an instance; estimated speed was 45 KM/H.

Here are the sequence of events:
a) loose chain + bumpy asphalt derails chain to the inboard of the
chainring.
b) chain then derails inboard at the cog
c) the chain's top run, now positioned between the cog and flange,
is hooked by the wheels outbound spokes; it's pulled down and around
the hub, further wedging itself between the cog and flange/spokes.
d) Running out of length, the chain jams. At the time this was
evidenced by a brief but intense shuddering, grinding protest from the
rotating wheel, as the chain and spokes milled themselves.
e) Now the chain, with the force of the bike's momentum behind it,
was exerting an outbound, counterclockwise force on the cog as the
spokes tried to wrap it more tightly around the hub.
d) The wheel locks up for an instant; but the path of least
resistance is my ersatz lockring/hub combo rather than the friction of
rubber on dry asphalt.
f) Cog liberated...
Luke

Pretty awesome Luke, 45 KM/H = 27.9617 mph.. I had to ask about derailing
the chain because I did this once at the Hellyer Park Velodrome in San Jose
when I had too much slack in the chain. The chain got wedged between the
bottom bracket spindle cup and the crank around the curved bank. The sad
part was I was strapped in tight and didn't release from the bike. It was
more embarrassing than actually hitting the cement. From then on, I always
made sure I adjusted the slack to the tightest part of the chain.
-tom

"Paul Hobson" wrote in message
...
James Thomson wrote:


Did you know about the fixed-gear mailing list? Subscription details are
at:

http://lists.davintech.ca/mailman/listinfo/fixed-gear

James Thomson

Thanks for that link, I'll check it out

\\paul

Here's another fun site:
http://www.fixedgeargallery.com/
You wouldn't think there was so many of us.
-tom

Tom Nakashima wrote:
"Paul Hobson" wrote in message
...

James Thomson wrote:


Did you know about the fixed-gear mailing list? Subscription details are
at:

http://lists.davintech.ca/mailman/listinfo/fixed-gear

James Thomson

Thanks for that link, I'll check it out

\\paul


Here's another fun site:
http://www.fixedgeargallery.com/
You wouldn't think there was so many of us.
-tom

oh man...I've been a regular at that bike porn site for a while now...I
never get enough.

\\paul

Tom Nakashima wrote:
"Paul Hobson" wrote in message
...

Can you friend who rides sans lockring do track stands when the hill
slopes downward?

\\paul
www.fastermustache.org


My friend is a lot heavier than I, and has a lot of power in his legs. I'm
really not sure why he doesn't use an inexpensive lock ring since he can
also ride his fixie backwards, or at least do a figure 8 backwards. We both
can do track stands, but it's a balance thing. I not sure if the track
stand you're referring to is making a skid...that I can't do, but my friend
will sometimes leave his mark. [snip]

My question wasn't clear, sorry. When you're doing a track stand
(standing still at a red light) facing uphill, you primarily have to
apply pressure forward, which would work to tighten the cog.
Conversely, a track stand at a light facing downhill, you primarily have
to apple pressure *backward*, which would work to *loosen* the cog --
which would in turn have the bike creep foward and the go would not
rotate as much as the wheels, thus, unscrewing.

So what I was asking was if track standing facing down a hill
representive of your area would cause in sprocket to unthread.

Does that even make sense? sorry...

\\paul
--
Paul M. Hobson
Georgia Institute of Technology
..:change the words to numbers
if you want to reply to me:.

"Paul Hobson" wrote in message
...

So what I was asking was if track standing facing down a hill representive
of your area would cause in sprocket to unthread.

Does that even make sense? sorry...

\\paul
--
Paul M. Hobson
Georgia Institute of Technology
.:change the words to numbers
if you want to reply to me:.

Paul, to answer your question, the answer is "no" there wouldn't be enough
backwards force on a down hill slope doing a track stand that would unthread
the cog. You really have to put a lot of force on the cog to unloosen it.

To install the cog, I give it a good solid turn with my cog chain wrench,
and then add the reverse (left hand thread) locking ring a little past
finger tight. I then find a hill to climb and most likely I have to
ever-so-slightly retighten the lockring.

My friend who rides without a lockring has to really stand on the pedals to
break loose the cog. Even when I use my cog chain wrench I have to put on a
lot of force to remove it.

Since I love climbing hills with my fixie, I have a 46t front and a 20t rear
which gives me about 62.1 gear inches. I can ride pretty steep hills in the
gear, but the downside is on the flats I have a high cadence. The flip-flop
makes sense, or even carrying an extra few cogs and wrench, but I'm lazy.
-tom

In article , Tom Nakashima
wrote:

Pretty awesome Luke, 45 KM/H = 27.9617 mph..

Well, I wish I could attribute the warp speed to my Nothstein-like
thighs, but the hill's grade definitely played a part! ;-). Really, at
the time, the cadence was managing me as opposed to the reverse: I was
in the proverbial ass-pogoing pedalling mode and transmitting no power
to the pavement.

I'm laughing now just thinking about it. I'd like to believe that a
burst of sparks fanned out from my mobile chain grinder as it sped
through the night - that would've made it really awesome!

Luke

"Tom Nakashima" wrote:

Pretty awesome Luke, 45 KM/H = 27.9617 mph..

Not correct. Tom, if you are either faculty or student at Stanford, you
should know something about significant digits. That conversion is a
common source of error in many computations.

45.0000 km/h = 27.9617 mph
45 km/h = 28 mph

--
Ted Bennett

"Ted Bennett" wrote in message
...
"Tom Nakashima" wrote:

Pretty awesome Luke, 45 KM/H = 27.9617 mph..

Not correct. Tom, if you are either faculty or student at Stanford, you
should know something about significant digits. That conversion is a
common source of error in many computations.

45.0000 km/h = 27.9617 mph
45 km/h = 28 mph

--
Ted Bennett

Sorry Ted, I was only off by -.0383 mph.
-tom