Strange weight related question

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can anybody
out my mind at rest and reassure me that this bike can take my weight?

I am interested in how much weight bikes can take as this seems to be a
rather vague subject. Obviously it depends on how the bike is used but
isn't there some kind of benchmark, like typical road use? The modern
trend towards fewer spokes, which saves on manufactuing costs, is
counterproductive strengthwise. One of my bikes has 40 spoke wheels and
I was astonished the other day to see a BMX bike in Halfords with 60
spoke wheels!

I wouldn't think 18st is at all unusual, maybe 25st+ is but I could be
wrong on this.

Doug.

Doug said:

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can
anybody out my mind at rest and reassure me that this bike can take
my weight?

I am interested in how much weight bikes can take as this seems to be
a rather vague subject. Obviously it depends on how the bike is used
but isn't there some kind of benchmark, like typical road use? The
modern trend towards fewer spokes, which saves on manufactuing costs,

More to make them more fashionable now. Original idea I think was to
increase aerodynamics and save weight.

Quoted message said:

is counterproductive strengthwise.

To try and make up for this, they tend to use stiffer (and heavier!) rims,
if not heavier spokes as well.

Wheels aside, only the lightest and flimsiest bikes will have a problem
with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with good
rims (eg. Mavic Open Pro or CXP33).

~PB

Pete Biggs said:

Doug said:

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can
anybody out my mind at rest and reassure me that this bike can take
my weight?

I am interested in how much weight bikes can take as this seems to be
a rather vague subject. Obviously it depends on how the bike is used
but isn't there some kind of benchmark, like typical road use? The
modern trend towards fewer spokes, which saves on manufactuing costs,

More to make them more fashionable now. Original idea I think was to
increase aerodynamics and save weight.

Quoted message said:

is counterproductive strengthwise.

To try and make up for this, they tend to use stiffer (and heavier!) rims,
if not heavier spokes as well.

Wheels aside, only the lightest and flimsiest bikes will have a problem
with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with good
rims (eg. Mavic Open Pro or CXP33).

~PB

I must admit to be nearing that weight, and not daring to get on my
Softride in case I snap the beam!

Which is a shame, as I've only got an OCR3 with minimal brakes otherwise
(:

Steve

in message <[email hidden]>,

Doug (') said:

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can
anybody
out my mind at rest and reassure me that this bike can take my
weight?

I am interested in how much weight bikes can take as this seems to be a
rather vague subject. Obviously it depends on how the bike is used but
isn't there some kind of benchmark, like typical road use? The modern
trend towards fewer spokes, which saves on manufactuing costs, is
counterproductive strengthwise.

Reduced spoke count certainly does not have anything to do with saving
manufacturing costs - quite the opposite. Furthermore, some reduced
spoke count wheels are amazingly strong - the 18 spoke front wheel which
took the full force of the impact of the 46mph crash in which I broke my
back was still perfectly true afterwards, although the rim was slightly
dented.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Good grief, I can remember when England won the Ashes.

[[[Doug said:

]]']The modern trend towards fewer spokes, which saves on manufactuing costs...

Thats not what that is all about. The speed the tops of your wheels are doing relative to the velocity of the air is twice the rolling speed if there is no wind.

Obviously therefore when you are doing high speeds like 40mph the speed difference of the air and the rim is 80mph. When you consider the parasitic drag force from the air quadrouples everytime you double the speed and furthermore the power requirement increases by a factor of 8(!) when doubling the speed you realise how much power it takes to rotate a wheel quickly. So by making the spokes more aerodynamic you can save a whole load of energy and reducing the number helps. Also by blading them you can make them appear aerodynamically to be an 1/8 of the frontal area relative to circular ones.

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can anybody
out my mind at rest and reassure me that this bike can take my weight?

Cheers

When I was very overweight the only problem I had was that I broke the
rear spindle (axle)on one of my bikes. Actually I bent it severely and
it only broke when I took it out to service the hub. This is only
likely to be a problem if you have a freewheel rear hub. The currently
popular cassette hubs should be less inclined to bend or break under
load because the bearing points are more or less equidistant from the
dropouts. BTW, I wasn't quite 18 stone, but over 17 at the time.

--
Brian G

MichaelB said:

Doug said:

]]']The modern trend towards fewer spokes, which saves on manufactuing
costs...

Thats not what that is all about. The speed the tops of your wheels
are doing relative to the velocity of the air is twice the rolling
speed if there is no wind.

Obviously therefore when you are doing high speeds like 40mph the speed
difference of the air and the rim is 80mph. When you consider the
parasitic drag force from the air quadrouples everytime you double the
speed and furthermore the power requirement increases by a factor of
8(!) when doubling the speed you realise how much power it takes to
rotate a wheel quickly. So by making the spokes more aerodynamic you
can save a whole load of energy and reducing the number helps. Also by
blading them you can make them appear aerodynamically to be an 1/8 of
the frontal area relative to circular ones.

Yes but how does this relate to bikes with 20 spoke wheels sold to
non-athletic users? Are they really going to notice any difference,
except that their bike is not as strong as it could be?

Another point I would like to make is that bike trailers usually have a
maximum load recommendation so why not bikes themselves?

Doug.

Brian G said:

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can anybody
out my mind at rest and reassure me that this bike can take my weight?

Cheers

When I was very overweight the only problem I had was that I broke the
rear spindle (axle)on one of my bikes. Actually I bent it severely and
it only broke when I took it out to service the hub. This is only
likely to be a problem if you have a freewheel rear hub. The currently
popular cassette hubs should be less inclined to bend or break under
load because the bearing points are more or less equidistant from the
dropouts. BTW, I wasn't quite 18 stone, but over 17 at the time.

Was it a hollow, quick release axle?

Doug.

Quoted message said:

Brian G

in message <[email hidden]>,

Doug (') said:

Yes but how does this relate to bikes with 20 spoke wheels sold to
non-athletic users? Are they really going to notice any difference,
except that their bike is not as strong as it could be?

Another point I would like to make is that bike trailers usually have a
maximum load recommendation so why not bikes themselves?

Some (mostly time trial bikes, which tend to be built very light) do.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; this is not a .sig

Quoted message said:

Yes but how does this relate to bikes with 20 spoke wheels sold to
non-athletic users? Are they really going to notice any difference,
except that their bike is not as strong as it could be?

<shrugs> Most won't notice the wheels aren't as strong as they could be,
but will certainly notice the looks :-)

You don't really notice the difference between low and high end components
either, at least when they're both new.

Pete Biggs said:

Wheels aside, only the lightest and flimsiest bikes will have a problem
with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with good
rims (eg. Mavic Open Pro or CXP33).

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

David Belcher

[1] Approx 11 1/2 stone, I think.

"David E. Belcher" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

David Belcher

[1] Approx 11 1/2 stone, I think.

Just over 12 1/2 stones - either ask google or remember there are 454g in a
lb and 14 lb in a stone.

This is important - it would move me from being too heavy to ok for these
wheels!

cheers,
clive

in message <[email hidden]>, David

E. Belcher (') said:

Pete Biggs said:

Wheels aside, only the lightest and flimsiest bikes will have a
problem with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with
good rims (eg. Mavic Open Pro or CXP33).

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

Neither the Cosmic Carbone Pro nor the Ksyrium ES (which I[1] ride) have
any specified maximum rider weight, and they are the lightest wheels in
the Cosmic (time trial) and Ksyrium (road race) ranges. My friend
Dougie, who /is/ 18 stone, has a Comete disk on the back of his time
trial bike and a Cosmic Carbone on the front, and I've seen him do ten
miles in 24 minutes 20 on that bike.

So I'd be /very/ surprised if any Mavic wheel has a specified maximum
rider weight of 80Kg.

[1] 83Kg

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I can't work yanks out......
;; Why do they frown upon sex yet relish violence?
;; Deep Fried Lettuce

Doug said:

Brian G said:

Gregster said:

I've got a Ribble 7003 framed bike, a Chorus/Athena/Veloce mix and
Mavic Comsos wheels.

I haven't ridden for a few years and now weigh in at 18st. Can anybody
out my mind at rest and reassure me that this bike can take my weight?

Cheers

When I was very overweight the only problem I had was that I broke the
rear spindle (axle)on one of my bikes. Actually I bent it severely and
it only broke when I took it out to service the hub. This is only
likely to be a problem if you have a freewheel rear hub. The currently
popular cassette hubs should be less inclined to bend or break under
load because the bearing points are more or less equidistant from the
dropouts. BTW, I wasn't quite 18 stone, but over 17 at the time.

Was it a hollow, quick release axle?

Yes.

--
Brian G

David E. Belcher said:

Pete Biggs said:

Wheels aside, only the lightest and flimsiest bikes will have a problem
with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with good
rims (eg. Mavic Open Pro or CXP33).

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

David Belcher

[1] Approx 11 1/2 stone, I think.

I suspect this is the max load per wheel rather than rider weight.

Pete
--
"If people think nature is their friend,
then they sure don't need an enemy." - Vonnegut
mono[losethis]treme@ntlw{andthis>orld.com

Clive George said:

Quoted message said:

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

David Belcher

[1] Approx 11 1/2 stone, I think.

Just over 12 1/2 stones - either ask google or remember there are 454g in a
lb and 14 lb in a stone.

I've ridden a pair of Mavic Cosmos wheels at over 17 stone before, for
quite some time. They have 24 spokes front and 28 rear and I thought
they'd fold in half the moment I sat on them but they were as solid as
a rock. In the end I was so confident in their strength I was happy to
bump up and down kerbs every now and then, I wasn't at all cautious
with 'em. I think the OP will be fine on his.

"Bob"
--

Email address is spam trapped, to reply directly remove the beverage.

David E. Belcher said:

Pete Biggs said:

Wheels aside, only the lightest and flimsiest bikes will have a problem
with 18 stone.

Greg, it would be sensible to get some handbuilt 36-spoke wheels with good
rims (eg. Mavic Open Pro or CXP33).

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

David Belcher

[1] Approx 11 1/2 stone, I think.

I found this:

http://www.amclassic.com/tech/pdf/WheelWeightLimits2006.pdf

The weight limits range from 185 to 235 pounds (83 to 106kg) per wheel
and spoke counts 18 to 32. Presumably a 36/40 spoke wheel with a solid
axle could take more.

But what about frame weight limit?

Doug.

Simon Brooke said:

So I'd be /very/ surprised if any Mavic wheel has a specified maximum
rider weight of 80Kg.

I think the wheels in question were one of the lower-end models;
possibly the Classics Pro, since superseded by the Cosmos.

David Belcher

Pete Connors said:

Quoted message said:

Would second that - don't certain Mavic factory-built wheels have a
recommended rider weight limit; 80kg [1], I think (www.mavic.com
probably holds the answer)?

Quoted message said:

I suspect this is the max load per wheel rather than rider weight.

The heavy braking/disk brake/QR-skewer/unloaded rear wheel thread is
over there. ----> :-)

R.