Coker Reliability

I rode mine most of last season without any trouble. I'm over 200 lbs
and only use it only on the street (no jumping curbs for me). I
upgraded to the airfoil because I found I was using it more and more and
wanted to lighten up. I would say use it till it dies, then worry about
replacing.

--
Dirtsurfer - Singlewheel/Singletrack

"All we have to decide is what to do with the time that is given to us."
Gandalf the gray
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I muni'd with my coker all last season, and a lot of urdan/street miles
on it. I am about 180-90 with gear on, and go over curbs and stuff, as
well as through technical MUni trails.

The rim is definetly the weak point to the unicycle, but it is far from
'[censored]'.

You do, however, need to be more concerned with proper spoke tension, if
you plan on throwing curbs and things into your ride.

My Coker has been through quite a bit, and the rim is still 'true'
(true enough)

Here is a '18mb Video' (http://tinyurl.com/2xrat) of me showing the
wheel almost taco'ing, then springing back into shape again. Very
little spoke tensioning was required when I got home...it's still going
strong.

However, if I were to buy a new Coker, I'd get it with the aftermarket
Airfoil rim right from the start, I'm sure it would be a wise
move...because then you wouldn't have to worry at all. But as stated by
the other poster, I won't replace mine with the aftermarket until mine
dies.

Finesse overcomes the wheel's weaker points.

--
Sofa - You Tu Tu Tuni?

'It really doesn't matter, because in a few years, you will have every
size made' - chirokid's response to 20" or 24"?

'Unicycle Product Reviews' (http://tinyurl.com/368h6) *107* reviews on
*72* products

'London Unicycling Club Website ' (http://www.brianmackenzie.com/LUC/)
version 3.02

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Well, are US pounds the same as proper English ones? Coz I'm only 149
pounds (as of today) and I think I need to lose a few more.

Be that as it may, I've ridden my standard Coker on and off road, up
hill and down dale, through the merry greenwood and down by the
riverside, and all I do is get the local bike shop to true the rim every
few months.

I believe I'm right in saying that steel is stronger than aluminium
alloy, weight for weight (I recall this from my scuba diving days when
steel tanks were lighter than the aluminium equivalents), but the
problem with the stock Coker rim is that it is a very simple design,
rather hastily thrown together. Add to that that the wheel is machine
built, and the structure can be weak. Hand tensioning of the spokes by
someone who knows what (s)he's doing makes quite a difference.

If my standard Coker rim Croke-d, I would probably pay the extra for a
better one, but not before.

--
Mikefule - Roland Hope School of Unicycling

So many pedestrians tell me I've lost a wheel.
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Mikefule said:

*Well, are US pounds the same as proper English ones? Coz I'm only
149 pounds (as of today) and I think I need to lose a few more.*

149 pound (US) = 10.6428 Stone (UK)😄

--
brian.slater - Nellfurtiti, the Wonder Cat

Brian C. Slater
AKA: Snoopy

Ok, I am now officially in my normal state of -advanced- confusion.
Don't try to confuse me, it won't make any difference.

"To not decide is to decide" - undecided
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brian.slater said:

*149 pound (US) = 10.6428 Stone (UK)😄 *

So a pound's a pound, either side of the pond. But no Englishman would
put a decimal point in a weight in stones.:eek:

:p

--
Mikefule - Roland Hope School of Unicycling

So many pedestrians tell me I've lost a wheel.
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Mikefule said:

*
So a pound's a pound, either side of the pond. But no Englishman
would put a decimal point in a weight in stones.:eek:

:p *

149 pound (US) = 10,6428 Stone (UK)?

--
brian.slater - Nellfurtiti, the Wonder Cat

Brian C. Slater
AKA: Snoopy

Ok, I am now officially in my normal state of -advanced- confusion.
Don't try to confuse me, it won't make any difference.

"To not decide is to decide" - undecided
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brian.slater said:

*
149 pound (US) = 10,6428 Stone (UK)? *

149 pounds = a little over ten and a half stone or ten stone six.

Sarah ( UK)

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Mikefule said:

I believe I'm right in saying that steel is stronger than aluminium
alloy, weight for weight (I recall this from my scuba diving days when
steel tanks were lighter than the aluminium equivalents)

Actually, aluminum alloy and high grade steel are comparable in
tensile strength/weight. Aluminum parts are often stiffer than steel
because they have to be made thicker for the same tensile strength,
and so the aluminum resists bending better. Steel is less expensive.
So, aluminum rims can be lighter and stronger than steel. Steel tends
to be used for inferior rims to save money.

Ken

sarah.miller said:

149 pounds = a little over ten and a half stone or ten stone six.

What does the six refer to? Six tenths of a stone? That is a decimal
point in disguise.

Klaas Bil - Newsgroup Addict
--
I think profile should make some stronger 145mm cranks - Ryan Atkins

Sarah Miller said:

Quoted message said:

149 pounds = a little over ten and a half stone or ten stone six.

and Klaas Bil responded:

Quoted message said:

What does the six refer to? Six tenths of a stone? That is a decimal
point in disguise.

It refers to 6lbs over a stone. But, with a stone being 14lbs, I think
Sarah may have been a little tired when she posted.

What she should have written was:
149 pounds = a little over ten and a half stone or ten stone nine.

Which is, coincidentally, about what I weigh.

--
Danny Colyer (the UK company has been laughed out of my reply address)
http://www.speedy5.freeserve.co.uk/danny/
Why I like OE6 - http://www.speedy5.freeserve.co.uk/danny/misc/oe6.html
"He who dares not offend cannot be honest." - Thomas Paine

Klaas Bil said:

*That is a decimal point in disguise.*

A spy decimal point!!!😄 :eek:

I bet it even has an evil laugh.:p

--
brian.slater - Nellfurtiti, the Wonder Cat

Brian C. Slater
AKA: Snoopy

Ok, I am now officially in my normal state of -advanced- confusion.
Don't try to confuse me, it won't make any difference.

"To not decide is to decide" - undecided
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Ken Cline said:

*
Actually, aluminum alloy and high grade steel are comparable in
tensile strength/weight.
*

A little clarification: The -ratio- of strength to weight is about the
same for steel and aluminum.

Steel is three times stronger (in tension) and three times heavier than
aluminum. So an equivalent aluminum part is generally three times
thicker. This is the secret behind the stiffness of Cannondale and
Klein bicycles - since there is more aluminum to work with the tubes can
be made in larger diameters which are MUCH stiffer because the material
is further away from the centerline and has more leverage against the
bending.

But getting back to rims, they don't fail in tension. They twist and
"buckle," which means that they fold up under compressive loads. Think
of what happens to a rim when the wheel tacos - it picks up four gradual
twists. And if you've ever seen a broken rim you can see it has picked
up three distinct folds - one in and two out. Both of these
deformations are the rim's way of escaping from the huge compressive
loads that tensioned spokes create.

Torsional resistance and buckling strength are very dependant on the
geometry of the part. A thick-walled tube, like an extruded aluminum
rim, is much stronger under compressive loads than a thin sheet that has
been formed into a C-shape, and MUCH, MUCH more resistant to twisting
loads. My structures professor demonstrated this with a cardboard tube
from a roll of paper towels. The torsional stiffness of the tube
disappeared when he slit it lengthwise.

So the stock Coker rim is weak because of it's shape, not because of the
material. Aluminum rims are stronger because aluminum is easily
extruded into those nice tubular shapes. Those nice rim sections could
be done in steel but it would be prohibitively expensive.

--
cyberbellum - Level 1.0 rider!

Optimists think the glass is half full. Pesimists think the glass is
half empty. Engineers think the glass is too big.
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What does the six refer to? Six tenths of a stone? That is a decimal
point in disguise.

10 stone 6 means 10stone 6lbs(pounds) where there are 14 lbs in a
stone
Oh the joys of imperial weights and measures

Roland

--
roland
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roland said:

*What does the six refer to? Six tenths of a stone? That is a decimal
point in disguise.

10 stone 6 means 10stone 6lbs(pounds) where there are 14 lbs in a
stone
Oh the joys of imperial weights and measures

Roland *

That is my point. 149 lbs should be 10 stone 9, not 10 stone 6. More
proof that the imperial system is confusing even to the English - as if
we need more proof.

Klaas Bil

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I weight about 200 lbs. For the longest time my Coker (completely
stock), was my only unicycle. I beat the hell out of it, and never had
any problems. Until I bent the crank, which I believe are just cheap
lascos. So that's certainly no fault of the coker. I have found the
coker to be quite durable.

--
tortoise
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Klaas Bil said:

*That is my point. 149 lbs should be 10 stone 9, not 10 stone 6. More
proof that the imperial system is confusing even to the English - as
if we need more proof.

Klaas Bil *

Absolutely - I was lazy and didn't look at the figure that was being
converted assuming that the good folk of England would still have their
dark ages measuring hats on and so would have got it right 🙂 Just as
well we went decimal on the coinage or ordering unicycle bits on the web
would have been a nightmare

Roland

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I wouldn't rush out to buy a new rim, but if I broke the one that I have
I would upgrade to the airfoil.

carjug

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Klaas Bil said:

*That is my point. 149 lbs should be 10 stone 9, not 10 stone 6. More
proof that the imperial system is confusing even to the English - as
if we need more proof.

Klaas Bil *

149 pounds **is** 10 stone 9.

1 stone = 14 pounds
10 stone = 140 pounds

1 pound = 16 ounces.
Just to make it easy.

No one would normally express 10 stone 9 as 10.6 stone.
This is because the deciomal point would imply a decimal system, and
clearly a system of 1/14 and 1/16 is not decimal.

In the USA, they use pounds, rather than stones. Hence, an American
would say 149 pounds and an Englishman would say 10 stone 9.

My question which started all this was (facetiously) whether US pounds
were the same weight as UK pounds. Not an entirely daft question as US
gallons are different from UK gallons. It was prompted by several
people referring to their own weights as being about equivalent to the
weight of me carrying all my unicycles and a bucket of heavy water.

😉

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So many pedestrians tell me I've lost a wheel.
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Mikefule said:

*

My question which started all this was (facetiously) whether US pounds
were the same weight as UK pounds. Not an entirely daft question as
US gallons are different from UK gallons. It was prompted by several
people referring to their own weights as being about equivalent to the
weight of me carrying all my unicycles and a bucket of heavy water.

😉 *

Now I'm really confused! All that Stone stuff had me going, and now we
have to figure out the weight of "heavy water." Normal water is about
8.34 lbs/US gal, but i guess we'll have to ask Harper about heavy
water.

Just to stay somewhat on topic...i've had my standard Coker for about 4
years now. It doesn't get ridden on any real tough terrain, but it has
worn out two tires with no rim problems. I'd love to have the airfoil
rim, but like others have said, i probably won't upgrade until i fold
the stock one. One thing, though, i wouldn't recommend trying to use
brakes on the stock rim. I tried it for a little while, but my rim has
such a bulge at the weld that it is impossible to modulate...sent me
flying too many times!

Chuck

--
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I live in my own little world but its ok...they know me here!

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