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-   -   maximum weight on a Bianchi Eros frame. (http://www.cyclebanter.com/showthread.php?t=95711)

TLOlczyk July 20th 05 05:58 AM

maximum weight on a Bianchi Eros frame.
 
Ok. For about the last nine months I've been sidelined with some real
nasty Achilles tendonitis. That ( plus a change in medications to one
that causes weight gain ) has caused my weight to really scoot up.
Now that the pain is subsiding, and I am ready to get back on a bike
can someone tell me what the maximum weight that the frame on a
Bianchi Eros can handle is?

Thanks



The reply-to email address is .
This is an address I ignore.
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**
Thaddeus L. Olczyk, PhD

There is a difference between
*thinking* you know something,
and *knowing* you know something.

Chalo July 20th 05 10:43 AM

maximum weight on a Bianchi Eros frame.
 
TLOlczyk wrote:

Ok. For about the last nine months I've been sidelined with some real
nasty Achilles tendonitis. That ( plus a change in medications to one
that causes weight gain ) has caused my weight to really scoot up.
Now that the pain is subsiding, and I am ready to get back on a bike
can someone tell me what the maximum weight that the frame on a
Bianchi Eros can handle is?


The frame can carry pretty much whatever you put on it, for a while at
least. (Remember the Viet Cong hauling 500 lbs. or more along unpaved
roads on old French road bikes?) It's the wheels, and the square taper
crank if it has one, that are at the most risk of failure from heavy
loads. Next in line is probably the fork steerer. (If you have an
Eros with a carbon/aluminum fork, I wouldn't be surprised if Bianchi
were willing to specify a weight limit for the fork, if you ask.)

This all presupposes that you are riding in a controlled fashion over
relatively good surfaces. For example, I managed to trash more frames
when I weighed in the mid-200s than later when I weighed in the
mid-300s, through a combination of highly athletic riding, lots of
miles, and inadvisable hijinks.

The couple of frame failures I have experienced while weighing above
350 lbs. have been sudden and dramatic. Both occurred while braking
hard with a special brake of my own design, though, and I don't believe
they would have been caused by the use of any commercially available
brake.

I wouldn't worry too much about it at this point. If your wheels fail
quickly, then you can concern yourself with what might go next. But if
they hold up OK, then I doubt you will have other structural problems.


Do switch to some kind of tubular spindle crank if your bike is
equipped with a square taper, though. When those things snap off-- and
that is the only way they fail structurally-- you can get seriously
hurt. One of the new 2-piece cranks with outboard-mounted BB bearings
would be a good choice.

Keep in mind that the risks you assume by not getting enough exercise
may be much graver than the risks you assume by riding a flimsy
bicycle. To mitigate both kinds of risk, however, you can always
upgrade to a sturdier bike.

Chalo Colina


Qui si parla Campagnolo July 20th 05 02:08 PM

maximum weight on a Bianchi Eros frame.
 


Chalo wrote:
TLOlczyk wrote:

Ok. For about the last nine months I've been sidelined with some real
nasty Achilles tendonitis. That ( plus a change in medications to one
that causes weight gain ) has caused my weight to really scoot up.
Now that the pain is subsiding, and I am ready to get back on a bike
can someone tell me what the maximum weight that the frame on a
Bianchi Eros can handle is?





Do switch to some kind of tubular spindle crank if your bike is
equipped with a square taper, though. When those things snap off-- and
that is the only way they fail structurally-- you can get seriously
hurt. One of the new 2-piece cranks with outboard-mounted BB bearings
would be a good choice.


Maybe you ought to see how much the gent weighs before you assume that
a square taper crank/BB will be unsafe. Many have ridden square taper
w/o problem for decades, and to paint it as 'unsafe' for nearly anybody
is not accurate.

In 20 years I have seen 3 BB square tapers break. I have also seen 2
octalink break and we will have to see about the two piece systems, as
they have only been around for 3 years so far.

Keep in mind that the risks you assume by not getting enough exercise
may be much graver than the risks you assume by riding a flimsy
bicycle. To mitigate both kinds of risk, however, you can always
upgrade to a sturdier bike.

Chalo Colina



[email protected] July 20th 05 05:06 PM

maximum weight on a Bianchi Eros frame.
 
Chalo wrote:
The frame can carry pretty much whatever you put on it, for a while at
least. (Remember the Viet Cong hauling 500 lbs. or more along unpaved
roads on old French road bikes?) It's the wheels, and the square taper
crank if it has one, that are at the most risk of failure from heavy
loads.


How exactly will a heavy load affect the bottom bracket spindle? I
would think the bottom bracket spindle is affected only by the amount
of force/power the motor/rider can put into it while turning the
cranks. No matter what load is being supported above the ground by the
frame and wheels, it does not cause the motor/rider to produce more
power/strength and stress the bottom bracket more.


Llatikcuf July 20th 05 07:08 PM

maximum weight on a Bianchi Eros frame.
 
Chalo wrote:


This all presupposes that you are riding in a controlled fashion over
relatively good surfaces. For example, I managed to trash more frames
when I weighed in the mid-200s than later when I weighed in the
mid-300s, through a combination of highly athletic riding, lots of
miles, and inadvisable hijinks.

The couple of frame failures I have experienced while weighing above
350 lbs. have been sudden and dramatic. Both occurred while braking
hard with a special brake of my own design, though, and I don't believe
they would have been caused by the use of any commercially available
brake.


Highly athletic at 350lbs?

[email protected] July 20th 05 08:47 PM

maximum weight on a Bianchi Eros frame.
 
Llatikcuf wrote:
Chalo wrote:


This all presupposes that you are riding in a controlled fashion over
relatively good surfaces. For example, I managed to trash more frames
when I weighed in the mid-200s than later when I weighed in the
mid-300s, through a combination of highly athletic riding, lots of
miles, and inadvisable hijinks.

The couple of frame failures I have experienced while weighing above
350 lbs. have been sudden and dramatic. Both occurred while braking
hard with a special brake of my own design, though, and I don't believe
they would have been caused by the use of any commercially available
brake.


Highly athletic at 350lbs?


Re-read the post. He did highly athletic riding when he weighed in the
mid 200s. As compared to when he weighed in the mid 300s. He broke
more frames when weighing less, mid 200s, than when he weighed more,
mid 300s. Weight is not the only or main reason frames break.


Chalo July 20th 05 11:06 PM

maximum weight on a Bianchi Eros frame.
 
Qui si parla Campagnolo wrote:

Chalo wrote:


Do switch to some kind of tubular spindle crank if your bike is
equipped with a square taper, though. When those things snap off-- and
that is the only way they fail structurally-- you can get seriously
hurt. One of the new 2-piece cranks with outboard-mounted BB bearings
would be a good choice.


Maybe you ought to see how much the gent weighs before you assume that
a square taper crank/BB will be unsafe. Many have ridden square taper
w/o problem for decades, and to paint it as 'unsafe' for nearly anybody
is not accurate.


As I've told you before, I have broken two square tapers under pedaling
loads alone; one when I weighed about 240 lbs., and the other when I
weighed about 260 lbs.

IMO this is not so far out of the normal range that the square taper
can be considered safe. The OP does consider himself enough heavier
than average to pose the question.

In 20 years I have seen 3 BB square tapers break. I have also seen 2
octalink break and we will have to see about the two piece systems, as
they have only been around for 3 years so far.


That's not terribly surprising about Octalink (it being a Shimano
product after all), but I did assume that the feeble little crankarm
splines would strip before the "pipe spindle" snapped.

Chalo Colina


Chalo July 20th 05 11:16 PM

maximum weight on a Bianchi Eros frame.
 
wrote:

Chalo wrote:
The frame can carry pretty much whatever you put on it, for a while at
least. (Remember the Viet Cong hauling 500 lbs. or more along unpaved
roads on old French road bikes?) It's the wheels, and the square taper
crank if it has one, that are at the most risk of failure from heavy
loads.


How exactly will a heavy load affect the bottom bracket spindle? I
would think the bottom bracket spindle is affected only by the amount
of force/power the motor/rider can put into it while turning the
cranks. No matter what load is being supported above the ground by the
frame and wheels, it does not cause the motor/rider to produce more
power/strength and stress the bottom bracket more.


The load in this case is the rider. The rider can load the BB spindle
in three primary ways: Asymmetric torque from pedaling forces on the
left side, symmetric torque from standing with pedals level, and
bending loads that are applied whenever either pedal has any force on
it (in any crank orientation) and whenever the chain has any tension on
it.

A heavy rider increases the magnitude of all three of these loads
compared to a lighter rider.

If the load on a bike is in the form of luggage or the like, then of
course the BB spindle will not be affected by that.

Chalo Colina


Chalo July 21st 05 12:06 AM

maximum weight on a Bianchi Eros frame.
 
Llatikcuf wrote:

Chalo wrote:


This all presupposes that you are riding in a controlled fashion over
relatively good surfaces. For example, I managed to trash more frames
when I weighed in the mid-200s than later when I weighed in the
mid-300s, through a combination of highly athletic riding, lots of
miles, and inadvisable hijinks.

The couple of frame failures I have experienced while weighing above
350 lbs. have been sudden and dramatic. Both occurred while braking
hard with a special brake of my own design, though, and I don't believe
they would have been caused by the use of any commercially available
brake.


Highly athletic at 350lbs?


I didn't say that.

However, since I'm 6'8" with a sturdy frame (and used to be even
taller), 300 lbs. represents a fit and strong weight for me. At 350+
lbs., I'm rather fat but still physically active and capable of
vigorous riding.

If you refer to the simple geometric principle that volume is
propotional to height^3, then you'll see that 6'8" and 300 lbs is
equivalent to 6'0" and 219 lbs., or 5'6" and 168 lbs. That's normal
for fit men of heavy build at those heights.

At my leanest (due to a combination of fanatical riding, vegan diet,
and "ethnopharmacology"), I measured 6'9" and about 220 lbs. That's
equivalent to 6'0" and 155 lbs., and it's not an ideal weight for
someone of naturally heavy build. I'm quite a lot stronger at 300 lbs
than at 220.

If you have had a failure of imagination about my physical scale, don't
feel bad about it. Bike, car, and airplane manufacturers do it all the
time.

Chalo Colina


Llatikcuf July 21st 05 01:51 AM

maximum weight on a Bianchi Eros frame.
 
If you refer to the simple geometric principle that volume is
proportional to height^3, then you'll see that 6'8" and 300 lbs is
equivalent to 6'0" and 219 lbs., or 5'6" and 168 lbs. That's normal
for fit men of heavy build at those heights.


that's not how I remember health class-

http://www.intmed.mcw.edu/clincalc/body.html

6' 8" 300# = BMI of 33
6' 0" 219# = BMI of 29.7
5' 6" 168# = BMI of 27.1

Not equivalent in my book

Equivalent would be:

6' 0" 243# BMI of 33
5' 6" 205# BMI of 33

Just an observation.



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