Rim split how?

On 16 Jan 2005 10:45:25 -0800, Ed <[email hidden]>

Quoted message said:

To kill time waiting for spring, anyone want to speculate how this happened:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

or

http://tinyurl.com/4tq2c

The accompanying text:

After the blessing of the children, the wind shifted in my favor. I still had to
push myself to continue, and I thought I could make it to my hard-earned fifty
mile campsite until I heard that dreaded sound-- hissssssssss. In an instant, I
was riding on a flat. I couldn't have picked a better place to have a puncture;
first off, I was not speeding down a hill; secondly, there was a well kept clean
lawn on which to do my work: thirdly, no menacing dogs. In no time, I'd patched
the inner tube. Examining the wheel I found what had caused the perforation; I
gasped with dismay, my wheel had split in two. I guess that was the last mile
that wheel would ever serve me.

Dear Ed,

Here's a guess.

Maybe the intial spoke tension was too high for the rim, so
cracks began to form around the spoke holes on inner wall of
double-wall rim?

The spokes then lost tension, so they were tightened up
again.

The cracks naturally get bigger again.

Repeat until cracks join from spoke hole to spoke hole?

Carl Fogel

Ed said:

To kill time waiting for spring, anyone want to speculate how this

happened:

Quoted message said:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

or

http://tinyurl.com/4tq2c

The text doesn't explain, but the picture makes it pretty explicit- the
inner wall of the rim split open between the spoke holes. Moreover,
it's an "aero" rim without eyelets:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

From other pictures I would guess that this is a Velocity Aeroheat 20"

rim on a recumbent Greenspeed trike.
(Second photo:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=24585&v=sq&size=large
) The rider also appears to be using fat, high-pressure Maxxis Hookworm
tires.

Quoted message said:

From that evidence, I would surmise that the sidewalls of the rim were

pushed apart to an unusual degree. The inner wall of the rim fatigued
and split at its weak spot.

Jeff

On Sun, 16 Jan 2005 12:38:08 -0700, [email hidden] may have

Quoted message said:

Maybe the intial spoke tension was too high for the rim, so
cracks began to form around the spoke holes on inner wall of
double-wall rim?

The spoke's tension is applied to the outer wall, not the inner.
(Outer as in "exposed to the world, not next to the tube".)

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

On 16 Jan 2005 10:45:25 -0800, Ed <[email hidden]> may have

Quoted message said:

To kill time waiting for spring, anyone want to speculate how this happened:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

or

http://tinyurl.com/4tq2c

Given the way it split, I'd expect that to be a fault in the
extrusion.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Werehatrack said:

On Sun, 16 Jan 2005 12:38:08 -0700, [email hidden] may have

Quoted message said:

Maybe the intial spoke tension was too high for the rim, so
cracks began to form around the spoke holes on inner wall of
double-wall rim?

The spoke's tension is applied to the outer wall, not the inner.
(Outer as in "exposed to the world, not next to the tube".)

Dear Werehatrack,

D'oh!

Carl Fogel

Quoted message said:

...

Quoted message said:

From other pictures I would guess that this is a Velocity Aeroheat 20"

rim on a recumbent Greenspeed trike.
(Second photo:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=24585&v=sq&size=large
) The rider also appears to be using fat, high-pressure Maxxis Hookworm
tires....

Would not a Catrike [1] be a more appropriate choice for this uphill
training method? 😉

I would consider the 53-406 Maxxis Hookworm [2] to be a rather wide tire
for the Aeroheat rim, as they are quite wide even for the 4-mm wider
Taipan rim [3].

[1] <http://www.catrike.com/>.
[2] <http://www.maxxis.com/products/bicycle/product_detail.asp?id=90>.
[3] <http://www.velocityusa.com/catalog/velocity_rims_recumbent.html>.

--
Tom Sherman - Near Rock Island

"Ed" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

To kill time waiting for spring, anyone want to speculate how this
happened:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

I've seen that happen a couple of times. One was definitely a bad extrusion,
and the other was definitely from too much tire pressure. Yours might be a
combination of the two, can't say. But if you were running a fairly wide mtb
slick (1.5 or larger) at high pressure (100psi or more) you're putting an
awful lot of pressure on the rim... far more than would be the case with a
standard road tire at higher pressures.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

Ed said:

To kill time waiting for spring, anyone want to speculate how this

happened:

Quoted message said:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

or

http://tinyurl.com/4tq2c

The text doesn't explain, but the picture makes it pretty explicit- the
inner wall of the rim split open between the spoke holes. Moreover,
it's an "aero" rim without eyelets:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

From other pictures I would guess that this is a Velocity Aeroheat 20"

rim on a recumbent Greenspeed trike.
(Second photo:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=24585&v=sq&size=large
) The rider also appears to be using fat, high-pressure Maxxis Hookworm
tires.

It's not a Greenspeed it is a Timuter. The failure occured just short of 10000
miles into a 13000 mile tour.

Ed said:

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

Ed said:

To kill time waiting for spring, anyone want to speculate how this

happened:

Quoted message said:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

or

http://tinyurl.com/4tq2c

The text doesn't explain, but the picture makes it pretty explicit- the
inner wall of the rim split open between the spoke holes. Moreover,
it's an "aero" rim without eyelets:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

From other pictures I would guess that this is a Velocity Aeroheat 20"

rim on a recumbent Greenspeed trike.
(Second photo:
http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=24585&v=sq&size=large
) The rider also appears to be using fat, high-pressure Maxxis Hookworm
tires.

It's not a Greenspeed it is a T[r]imuter. The failure occured just short of 10000
miles into a 13000 mile tour.

In other words, a Greenspeed clone built under license.

--
Tom Sherman - Near Rock Island

Ed said:

To kill time waiting for spring, anyone want to speculate how this happened:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

or

http://tinyurl.com/4tq2c

The accompanying text:

After the blessing of the children, the wind shifted in my favor. I still had to
push myself to continue, and I thought I could make it to my hard-earned fifty
mile campsite until I heard that dreaded sound-- hissssssssss. In an instant, I
was riding on a flat. I couldn't have picked a better place to have a puncture;
first off, I was not speeding down a hill; secondly, there was a well kept clean
lawn on which to do my work: thirdly, no menacing dogs. In no time, I'd patched
the inner tube. Examining the wheel I found what had caused the perforation; I
gasped with dismay, my wheel had split in two. I guess that was the last mile
that wheel would ever serve me.

looks like a tire pressure problem to me. how hard are you running
them? some manufacturers specify a maximum pressure based on tire size.
if pressure is within that spec, likely an extrusion problem.

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Ed said:

To kill time waiting for spring, anyone want to speculate how this

happened:

Quoted message said:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

Quoted message said:

or

http://tinyurl.com/4tq2c

The text doesn't explain, but the picture makes it pretty explicit- the
inner wall of the rim split open between the spoke holes. Moreover,
it's an "aero" rim without eyelets:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

Quoted message said:

Quoted message said:

From other pictures I would guess that this is a Velocity Aeroheat 20"

rim on a recumbent Greenspeed trike.
(Second photo:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=24585&v=sq&size=large

Quoted message said:

) The rider also appears to be using fat, high-pressure Maxxis Hookworm
tires.

Quoted message said:

From that evidence, I would surmise that the sidewalls of the rim were

pushed apart to an unusual degree. The inner wall of the rim fatigued
and split at its weak spot.

Jeff

Too much pressure in tyre.

Marty

Mike Jacoubowsky said:

But if you were running a fairly wide mtb
slick (1.5 or larger) at high pressure (100psi or more) you're putting an
awful lot of pressure on the rim...

/me goes and lets tyres down on Thorn touring bike

Mike Jacoubowsky said:

"Ed" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

To kill time waiting for spring, anyone want to speculate how this
happened:

http://www.crazyguyonabike.com/journal/page/pic/?o=as&pic_id=41571&v=1t&size=large

I've seen that happen a couple of times. One was definitely a bad extrusion,
and the other was definitely from too much tire pressure. Yours might be a
combination of the two, can't say. But if you were running a fairly wide mtb
slick (1.5 or larger) at high pressure (100psi or more) you're putting an
awful lot of pressure on the rim... far more than would be the case with a
standard road tire at higher pressures.

Hmmm... I am running 53-406 Maxxis Hookworm tires at 110-psi on Velocity
Taipan rims -should I be worried?

--
Tom Sherman - Near Rock Island

Tom Sherman said:

Hmmm... I am running 53-406 Maxxis Hookworm tires at 110-psi on

Velocity

Quoted message said:

Taipan rims -should I be worried?

Mmmmm... the Taipan's 28mm wide as opposed to a 24mm Aeroheat. I seem
to recall that some of the early Aeroheats suffered from a defective
extrusion, so you should be OK. If you're really paranoid, the
appropriately-named Velocity "Psycho" rim might be warranted.

Jeff "Just because you're paranoid doesn't mean they're not out to get
you" Wills

Quoted message said:

Tom Sherman said:

Hmmm... I am running 53-406 Maxxis Hookworm tires at 110-psi on
Velocity Taipan rims -should I be worried?

Mmmmm... the Taipan's 28mm wide as opposed to a 24mm Aeroheat. I seem
to recall that some of the early Aeroheats suffered from a defective
extrusion, so you should be OK. If you're really paranoid, the
appropriately-named Velocity "Psycho" rim might be warranted.

Jeff "Just because you're paranoid doesn't mean they're not out to get
you" Wills

I am not paranoid enough to rebuild three low mileage trike wheels with
new rims (especially considering than none are rim braked).

--
Tom Sherman - Near Rock Island

In article <[email hidden]>, jim beam says...

Quoted message said:

looks like a tire pressure problem to me. how hard are you running
them? some manufacturers specify a maximum pressure based on tire size.
if pressure is within that spec, likely an extrusion problem.

It did not happen to me. It is from a travelog of a woman who rode from North
Carolina to Alaska and back last year. She gives no information except that the
rim failed while she was just riding along about 10000 miles into the ride. I
posted the question because I could not imagine what could cause such a failure.

Quoted message said:

Quoted message said:

I've seen that happen a couple of times. One was definitely a bad
extrusion, and the other was definitely from too much tire pressure.
Yours might be a combination of the two, can't say. But if you were
running a fairly wide mtb slick (1.5 or larger) at high pressure (100psi
or more) you're putting an awful lot of pressure on the rim... far more
than would be the case with a standard road tire at higher pressures.

Hmmm... I am running 53-406 Maxxis Hookworm tires at 110-psi on Velocity
Taipan rims -should I be worried?

Curiously, the last "exploded" rim I saw was actually a '406 in a 'bent, now
that I think about it. I would suggest a call or email to Velocity might be
in order. I would absolutely, definitely have concern if it were a 26" wheel
with a tire of that width and that kind of pressure, but I'm not smart
enough to know if there's a reason that a smaller rim would have more
relative strength against that happening. Intuitively, I think the same
forces would be acting on the same amount of material.

I'm also thinking that most of this stress has little to do with riding, so
releasing some air when not in use might not be a bad idea.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com