I discovered today that inexpensive crank arms may be fine for street
riding, but not for muni. So, does anyone have any recommendations on who
makes a good (yet still, hopefully, inexpensive) crank arm? As the terrain
is quite flat around here, I’m probably looking at a 6" size.
I borrowed the crank arms from my Coker because they were the right
length. I really should have thought that through before I took them into
the woods. I had to make a 6" jump up to a bridge, and I landed just hard
enough to bend one crank to the point where I could feel, but not see the
bend. Well, after that, I figured it wouldn’t make much difference if I
went for a 3’ drop.
That drop had the oddest feel – I felt the shock of the landing as it was
absorbed by the pedal… which, unlike other drops I’ve made on my 20"
uni, did not apply any of that force back to my foot.
Also learned that day, riding a mile on a dirt trail with two bent cranks
can be interesting.
That’s funny, this strange feeling happened to me yesterday actually with
my monty uni. I was doing a 2’ drop on a steep slope, landed quite
brutally and really felt the right crank bending. When I reached flat
ground I checked the crank and mysteriously it was intact.
I’m wondering if a crank can really deform slightly and get back to its
primary shape or it’s just an illusion maybe due to the shock on the lower
leg / unprepared / over-contracted muscles ?
As a matter of fact I never bent my bicycle euro 140mm on trials.
I discovered today that inexpensive crank arms may be fine for street
riding, but not for muni. So, does anyone have any recommendations on who
makes a good (yet still, hopefully, inexpensive) crank arm? As the terrain
is quite flat around here, I’m probably looking at a 6" size.
I borrowed the crank arms from my Coker because they were the right
length. I really should have thought that through before I took them into
the woods. I had to make a 6" jump up to a bridge, and I landed just hard
enough to bend one crank to the point where I could feel, but not see the
bend. Well, after that, I figured it wouldn’t make much difference if I
went for a 3’ drop.
That drop had the oddest feel – I felt the shock of the landing as it was
absorbed by the pedal… which, unlike other drops I’ve made on my 20"
uni, did not apply any of that force back to my foot.
Also learned that day, riding a mile on a dirt trail with two bent cranks
can be interesting.
My limited knowledge physics tells me that yes, the crank arms will be
deformed to a certain degree, before returning back to their original
shape. If, however, the force you land with excedes the elastic limit of
the crank arms, they will not spring back.
My impression is that as you get into the “better” materials, the elastic
limit is not increased, but the amount that the pedals tend to flex with
the same force is decreased. By this logic, cheaper cranks would tend to
bend out of shape, whereas the more expensive ones would more likley snap
(though a lot more force would be required).
My uneducated guess would be that that this bending feeling is more due to
a flex in the spokes then anything with the cranks. It makes me wonder,
though, just how much flex the average set of crank arms have before they
break or become permanently misshapen. I would suspect if the cranks are
long enough, and have a good amount of flex, you very well could feel it.
Jeff Lutkus
— “Olivier Paugam” <opaugam@aptilon.com> > wrote: That’s funny, this strange feeling happened to me yesterday > actually with my monty uni. I was doing a 2’ drop on a steep slope, > landed quite brutally and really felt the right crank bending. When I > reached flat ground I checked the crank and mysteriously it was intact. > >I’m wondering if a crank can really deform slightly and get back to its >primary shape or it’s just an illusion maybe due to the shock on the >lower leg / unprepared / over-contracted muscles ? > >As a matter of fact I never bent my bicycle euro 140mm on trials. > >Oli- > >-----Original Message----- From: Jeff Lutkus >[mailto:lutkus@unicyclist.com] Sent: Thursday, July 05, 2001 8:42 AM To: >unicycling@winternet.com Subject: crank arms > > >I discovered today that inexpensive crank arms may be fine for street >riding, but not for muni. So, does anyone have any recommendations on who >makes a good (yet still, hopefully, inexpensive) crank arm? As the >terrain is quite flat around here, I’m probably looking at a 6" size. > >I borrowed the crank arms from my Coker because they were the right >length. I really should have thought that through before I took them into >the woods. I had to make a 6" jump up to a bridge, and I landed just hard >enough to bend one crank to the point where I could feel, but not see the >bend. Well, after that, I figured it wouldn’t make much difference if I >went for a 3’ drop.=20 > >http://www.rit.edu/~jvl2957/bent_crank.jpg > >That drop had the oddest feel – I felt the shock of the landing as it >was absorbed by the pedal… which, unlike other drops I’ve made on my >20" uni, did not apply any of that force back to my foot. > >Also learned that day, riding a mile on a dirt trail with two bent cranks >can be interesting. > >Jeff Lutkus > > >_____________________________________________________________ >Free e-Mail and Webspace - http://Unicyclist.com
This message is in MIME format. Since your mail reader does not understand
this format, some or all of this message may not be legible.
------_=_NextPart_000_01C1056F.71F365D0
charset="iso-8859-1"
> That’s funny, this strange feeling happened to me yesterday actually > with my monty uni. I was doing a 2’ drop on a steep slope, landed quite > brutally and really felt the right crank bending. When I reached flat > ground I checked the crank and mysteriously it was intact.
>This message is in MIME format. Since your mail reader does not >understand this format, some or all of this message may not be legible. > >------_=_NextPart_000_01C1056F.71F365D0
How many miles have you put on your Coker with 5" cranks? David Stone will
tell you it takes 20 miles, and I have to say, I think he might be right.
I think he’s done about 1000 on his 5’s. I was nervous with the 5’s, at
first, but now that I’ve done 100 miles on them, I wouldn’t consider 5.5s.
And I’m doing this in busy NYC. I’m no daredevil, I just love the feel of
the 5s - very smooth. It seems especially scary at first when hitting
bumps at high speed, but once you start relaxing and letting the momentum
of the wheel carry you through, no big deal. My 2 cents. Joe Merrill
In a message dated 7/13/01 12:35:18 AM Eastern Daylight Time, lutkus@unicyclist.com writes:
> On my coker: 6" cranks feel just slightly too long. 5" feel just > slightly too short. Does anyone know where to find a reasonable pair of > crank arms in the 5.5" range? > >
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>Jeff, <BR> <BR>How many
miles have you put on your Coker with 5" cranks? David Stone will
<BR>tell you it takes 20 miles, and I have to say, I think he might be
right. I <BR>think he’s done about 1000 on his 5’s. I
was nervous with the 5’s, at <BR>first, but now that I’ve done 100 miles
on them, I wouldn’t consider 5.5s. <BR>And I’m doing this in busy
NYC. I’m no daredevil, I just love the feel of <BR>the 5s - very
smooth. It seems especially scary at first when hitting bumps <BR>at
high speed, but once you start relaxing and letting the momentum of the
<BR>wheel carry you through, no big deal. My 2 cents. <BR>Joe
Merrill <BR> <BR>In a message dated 7/13/01 12:35:18 AM Eastern Daylight
Time, <BR>lutkus@unicyclist.com writes: <BR> <BR> <BR><BLOCKQUOTE
TYPE=CITE style=“BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px;
MARGIN-RIGHT: 0px; PADDING-LEFT: 5px”>On my coker: 6" cranks feel just
slightly too long. 5" feel just slightly <BR>too short. Does
anyone know where to find a reasonable pair of crank arms <BR>in the 5.5"
range? <BR> <BR></FONT><FONT COLOR="#000000" SIZE=3 FAMILY=“SANSSERIF”
FACE=“Arial” LANG=“0”></BLOCKQUOTE> <BR></FONT><FONT COLOR="#000000"
SIZE=2 FAMILY=“SANSSERIF” FACE=“Arial” LANG=“0”> <BR></FONT></HTML>
>On my coker: 6" cranks feel just slightly too long. 5" >feel just >slightly too short. Does anyone know where to >find a reasonable pair of >crank arms in the 5.5" range?
I’m running 140mm (5.5") on my Coker. Aluminium (Lasco) from unicycle.com
(both UK & US stock them: http://www.unicyclesource.com/Lasco116107.html I
find them smooth enough for flat and just about enough leverage for the
type of hills I’m attempting to ride. With 5’s I would struggle on the
ups/downs.
>On my muni: I am in the market for a good set of crank >arms. Bicycle >euro didn’t cut it for me, unfortunately. >Can anyone recommend any >cotterless crank types? (I’m a >fan of 150mm)
I’m still running original DM 150’s, which seem to hold up to 14stone of
me hopping around - note I’ve not done anything too drastic, i.e. never
more than a 1’ drop.
>I hear the profile splined hub and cranks come with a >lifetime warrenty. >Has anyone had the chance to put this >guarentee to the test? How good >are they about >replacement?
Sorry, no experience as yet.
SIMON
|
Simon Greenway | I.O.U O
I.O.U@mindless.com | | Romsey, Hampshire, UK. | Idiots On
Unicycles \#/
| <a href="http://come.to/muni">http://come.to/muni</a> o
inevitable stuff about air saddle coming to my site soon
Regarrding 5" cranks on a Coker, I would imagine there are hills that will
be a problem, but I haven’t encountered many hills yet, as I have ridden
mostly in NYC. I was worried about bumps and short stops at first, but I
guess I just allow extra space knowing I need more room to stop and
maneuver. I’ve found with bumps at high speed the key is just to relax and
ride through it, let the momentum of the wheel carry you through it.
Probably the only thing that would force me to use a crank greater than 5"
would be big hills.
Joe
In a message dated 7/13/2001 10:45:34 AM Eastern Daylight Time, jack@kanji.org writes: > > I love the smoothness too. I only tried it for 5 miles or so, but, as I > worte earlier, I don’t feel confident when I need to make sudden stops, > go over bumps, idle, make sharp turns etc.How do you handle that with > 5"? I am also worried since there are some pretty steep hills around my > neighborhood. > >
<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>Regarrding 5" cranks on a
Coker, I would imagine there are hills that will <BR>be a problem,
but I haven’t encountered many hills yet, as I have ridden <BR>mostly in
NYC. I was worried about bumps and short stops at first, but I
<BR>guess I just allow extra space knowing I need more room to stop and
maneuver. <BR> I’ve found with bumps at high speed the key is just to
relax and ride <BR>through it, let the momentum of the wheel carry you
through it. Probably the <BR>only thing that would force me to use a
crank greater than 5" would be big <BR>hills. <BR> <BR>Joe <BR> <BR>
<BR>In a message dated 7/13/2001 10:45:34 AM Eastern Daylight Time,
<BR>jack@kanji.org writes: <BR><BLOCKQUOTE TYPE=CITE style=“BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT:
5px”> <BR>I love the smoothness too. I only tried it for 5 miles or so,
but, as I <BR>worte earlier, <BR>I don’t feel confident when I need to
make sudden stops, go over bumps, <BR>idle, <BR>make sharp turns etc.How
do you handle that with 5"? I am also worried since <BR>there are
some pretty steep hills around my neighborhood. <BR> <BR></FONT></HTML>
