Stouter OC Rims?

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

TIA

D'ohBoy

Velocity Synergy - it's what Rivendell puts on most of their bikes.
They're 490g though.

There's a set of 32h/700c, F&R on ebay for $70 BIN, $10 S&H.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280157253979

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

Stay away from the Ritchey Aero OCR rear rim, its weak! I have one
built up with Campy Chorus 9/10 rear hub and with *only* about 1000
miles on it, yet the rim has developed a crack around one of the
nipples. The crack is probably because of the anodizing and/or the
lack of eyelets or both. I am very disappointed and frustrated as I
thought an offset rim would make a nice strong rear wheel.

Interestingly, I have logged tens of thousands of miles on my other
two wheels that are both built up with DA9hubs/Mavic Open Pro rim/
DT14/15 db spokes and aluminum alloy nipples. No cracks, broken spokes
or corroded or stripped nipples. Nothing. Both wheels are silent,
strong and still going.

Btw, Peter White, Master Wheelbuilder, recommends Mavic CXP-33, or one
of three Velocity rims: Fusion, Deep V or Synergy O/C. Good Luck!

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

TIA

D'ohBoy

fwiw, i weigh about 225 and the spoke holes of my synergy oc started
cracking in just under a year of moderate use, mostly commuting.
driveside tension around 105, built by me.

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

That is what the last Aeroheads I got actually weighed... 420g front,
430g rear. Pretty solid rim.

Quoted message said:

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

Or maybe a Fusion... *not* the Synergy.

bfd said:

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

Stay away from the Ritchey Aero OCR rear rim, its weak! I have one
built up with Campy Chorus 9/10 rear hub and with *only* about 1000
miles on it, yet the rim has developed a crack around one of the
nipples. The crack is probably because of the anodizing and/or the
lack of eyelets or both.

while some rims are just [censored] and crack regardless, /most/ rim cracking
is almost always due to excess spoke tension, not anodizing.

Quoted message said:

I am very disappointed and frustrated as I
thought an offset rim would make a nice strong rear wheel.

did you build with rim manufacturer specified spoke tension? assuming
the rim was ok quality, if you exceeded spoke tension spec. by seeking
spoke tension "as high as the rim can bear", it's not the rim's fault.
suggest you re-build using a tensiometer and the rim manufacturer's
spoke tension spec.

Quoted message said:

Interestingly, I have logged tens of thousands of miles on my other
two wheels that are both built up with DA9hubs/Mavic Open Pro rim/
DT14/15 db spokes and aluminum alloy nipples. No cracks, broken spokes
or corroded or stripped nipples. Nothing. Both wheels are silent,
strong and still going.

Btw, Peter White, Master Wheelbuilder, recommends Mavic CXP-33, or one
of three Velocity rims: Fusion, Deep V or Synergy O/C. Good Luck!

he also recommends sticking to manufacturer spoke tension spec!

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

TIA

D'ohBoy

CXP-33s are good rims, I've got a pair laced to Ultegra hubs 36-3X and
they've stayed in true for almost four years, even riding some rough
gravel roads. I weigh 225#

Smokey

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight).

http://www.surlybikes.com/2006_05_01_blog_archive.html

Chalo

Chalo said:

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight).

http://www.surlybikes.com/2006_05_01_blog_archive.html

Chalo

I just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:
1. The instructions are vague, confusing, and out of date.
2. The rims are offset the "wrong" way, to the non-drive side.
3. The rims barely fit in a Park truing stand.
4. It's easier to dish the wheels in the Pugsley fork than in a truing
stand.
5. Ordinary rim strips, like the wide Velox, are far too puny. A
strip of duct tape is just right.
6. Because of the obscene weight, it's hard to mount the tires. Sit
down, put the wheel in your lap, and use a big steel tire lever like
the Park TL-5. And don't even bother with a hand pump - use an air
compressor.

-Vee

Nate Knutson said:

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight). Something in the
neighborhood of 420 - 430 gms for a little extra durability. I am
fairly certain these don't exist but I thought I would ask.

Quoted message said:

Otherwise I am going to use a cxp-33 which is only 20 - 40 gms more
than what I am looking for.

Quoted message said:

TIA

Quoted message said:

D'ohBoy

fwiw, i weigh about 225 and the spoke holes of my synergy oc started
cracking in just under a year of moderate use, mostly commuting.
driveside tension around 105, built by me.

Well..the single eyelet Velocity rims are very sensitive to tension,
incluing the Razor..they don't like more than 100 kgf...

I really like the Fusion, Deep V, Mavic CXP-33 and DT 1.2.

Vee said:

Chalo said:

D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight).

http://www.surlybikes.com/2006_05_01_blog_archive.html

Chalo

I just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:
1. The instructions are vague, confusing, and out of date.
2. The rims are offset the "wrong" way, to the non-drive side.

sounds like the "right" way to me - to reduce the bracing angle on the
drive side spokes, you need to shift the drillings towards the non-drive
side of the hub.

Quoted message said:

3. The rims barely fit in a Park truing stand.
4. It's easier to dish the wheels in the Pugsley fork than in a truing
stand.
5. Ordinary rim strips, like the wide Velox, are far too puny. A
strip of duct tape is just right.
6. Because of the obscene weight, it's hard to mount the tires. Sit
down, put the wheel in your lap, and use a big steel tire lever like
the Park TL-5. And don't even bother with a hand pump - use an air
compressor.

-Vee

quote='Chalo'D'ohBoy said:

I am looking for a somewhat stouter OC rim than the Velocity/Ritchey/
IRD, all of which go 390 or so gms (listed weight).

http://www.surlybikes.com/2006_05_01_blog_archive.html

Chalo[/QUOTE]
Large Marge is a super wide rim... and heavy. At over 60 mm wide, you need some very wide tires to go with "her". The 12 mm offset is attractive.
I have had very good results with the Velocity Synergy OC rims... using them with Sapim Race 14/15 DB spokes, Sapim Polyax nipples, tension balancing to withing 5% per side and running the tension @ 100 kgf. Getting the spoke alignment precise and the tension balance more precise makes the wheel more stable and durable. Use of double butted spokes really helps spread the peak loads and makes the wheel more durable.
However I am looking at Alex Rims CROSTINI T1.2 Features: Off set drilled rim profile for 700c Doublewall rear specific rim. Match with Crostini T 1.1; the non-offset version for front wheel without disc brake.

Take a look at the Alex Rims web site:

alexrims.comalexrims.comOpen ↗

under the Cross/Trekking link

jim beam said:

Vee said:

I just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:
1. The instructions are vague, confusing, and out of date.
2. The rims are offset the "wrong" way, to the non-drive side.

sounds like the "right" way to me - to reduce the bracing angle on the
drive side spokes, you need to shift the drillings towards the non-drive
side of the hub.

You missed something. The Pugsley frame-- for which the Large Marge
OC rims are made-- has dropouts offset 17.5mm over to the right side,
with 135mm spacing both front and rear. That's so that the chain will
clear the 3.7" tire in back, and the tire will clear the disc caliper
in front on removal and installation.

Because the dropouts are situated so far over to the right, the rim
must offset to the _left_, with its spoke holes offset towards the
drive side of the rim.

Chalo

daveornee said:

However I am looking at Alex Rims CROSTINI T1.2 Features: Off set
drilled rim profile for 700c Doublewall rear specific rim.

Cool! 23mm wide, 510g. That's a good one to know about.

Chalo

Vee said:

just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:

<snip>

Quoted message said:

6. Because of the obscene weight, it's hard to mount the tires. Sit
down, put the wheel in your lap, and use a big steel tire lever like
the Park TL-5.

Although I don't have any trouble mounting tires on it, the heaviest
wheel I've built to date features an 1.9 pound rim, 2.2 pound tire...
and a 22 pound hub. (It's an electric motor.) That sucker was a
chore just to lace up.

Surly seems to think that mounting tires on the Large Marge rim is
tricky enough to warrant a blog entry on the topic:
http://www.surlybikes.com/spew10.html

Quoted message said:

And don't even bother with a hand pump - use an air compressor.

How much work could it be just to get 8 psi? You should probably just
inflate it by mouth like a balloon.

Chalo

Chalo said:

jim beam said:

Vee said:

I just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:
1. The instructions are vague, confusing, and out of date.
2. The rims are offset the "wrong" way, to the non-drive side.

sounds like the "right" way to me - to reduce the bracing angle on the
drive side spokes, you need to shift the drillings towards the non-drive
side of the hub.

You missed something. The Pugsley frame-- for which the Large Marge
OC rims are made-- has dropouts offset 17.5mm over to the right side,
with 135mm spacing both front and rear. That's so that the chain will
clear the 3.7" tire in back, and the tire will clear the disc caliper
in front on removal and installation.

Because the dropouts are situated so far over to the right, the rim
must offset to the _left_, with its spoke holes offset towards the
drive side of the rim.

Chalo

ok, unaware of that. my answer applies to the situation described by
the o.p.

On Sun, 30 Sep 2007 02:27:49 -0000, Chalo <[email hidden]>

Quoted message said:

How much work could it be just to get 8 psi? You should probably just
inflate it by mouth like a balloon.

Chalo

Dear Chalo,

Actually, 3 psi is impressive:

"About the final use of the respiratory system, Jacobs says, 'I
learned more about the lungs not by studying wind for playing my
instrument, the tuba, singing, or trumpet playing, but by studying
defecation and childbirth—the study of what happens with breath
pressure.'"

"The pelvic pressure syndrome uses the respiratory musculature for
both childbirth and defecation. Abdominal muscles bear down,
increasing internal air pressure. The throat closes to contain the
pressure [the Valsalva maneuver]. Inside the body, air is under
considerable pressure, far more than required to play a wind
instrument."

"Often during master classes, Jacobs has a man blow into a modified
blood pressure gauge with as much air pressure as possible. Usually
he can only blow three pounds of static breath pressure as sensors in
the lungs protect the tissue and prevent larger pressures."

"Next, he has this man lie flat on his back on the floor and tense up
the muscles of his abdomen by isometric opposition. A small woman
[usually Mrs. Jacobs!] then stands on his chest and abdomen."

"'On the trumpet, which is the highest pressure instrument in the
brass family, I have measured many people and they hardly go up to
three pounds of pressure. The average will be between one-half and one
and one-half pounds. When they are working really hard, they may get
up to two to three pounds.'"

"This demonstration shows that the muscles of the abdomen can only
sustain a pressure around three pounds, but can also support 100
pounds or more."

http://abel.hive.no/trompet/tpin/respiratory.html

The strong-man trick of blowing up and bursting heavy balloons relies
on the fact that the unconstrained rubber expands enormously, but the
pressure remains very low. Eventually, the rubber stretches enough to
crack.

You can test this by pumping up an inner tube, which will expand and
burst without raising the gauge needle appreciably.

When I tested a 700c x 23 tube long ago, my floor pump gauge read 0
after 80 strokes:

http://groups.google.com/group/rec.bicycles.tech/msg/ae49bf49bf2dda29

Here's a picture, showing the expanded inner tube:

http://home.comcast.net/~carlfogel/download/212_700c_80_pump_strokes_0_psi_4_feet_wide.jpg

The strong-man trick of bursting ballons is a dangerous stunt, since
our lungs aren't good at taking even that tiny pressure difference.

Cheers,

Carl Fogel

Chalo said:

Vee said:

just built up a set of wheels with those Large Marge rims for my
Pugsley. It was difficult! Key findings:

<snip>

Quoted message said:

6. Because of the obscene weight, it's hard to mount the tires. Sit
down, put the wheel in your lap, and use a big steel tire lever like
the Park TL-5.

Although I don't have any trouble mounting tires on it, the heaviest
wheel I've built to date features an 1.9 pound rim, 2.2 pound tire...
and a 22 pound hub. (It's an electric motor.) That sucker was a
chore just to lace up.

Surly seems to think that mounting tires on the Large Marge rim is
tricky enough to warrant a blog entry on the topic:http://www.surlybikes.com/spew10.html

It would be awfully tough with plastic levers. I wouldn't try. Not a
problem with metal levers, though.

Quoted message said:

Quoted message said:

And don't even bother with a hand pump - use an air compressor.

How much work could it be just to get 8 psi? You should probably just
inflate it by mouth like a balloon.

Chalo

It's not physically difficult with a hand pump, just tedious. It
takes lots of pumping before the tube begins to fill out.

-Vee

Carl Fogel said:

Chalo said:

How much work could it be just to get 8 psi? You should probably just
inflate it by mouth like a balloon.

Actually, 3 psi is impressive:

It's true. I have learned from some of my friends who dive that lungs
are irreversibly injured at pressure differentials of less than 5psi.
That's the reason for cultivating the habit of exhaling continuously
on ascent.

I spoke figuratively, to emphasize the very low pressures necessary
for the Endomorph tire.

Chalo