Too fat for Campag?

[Tin Pot]

Never saw this before, but looks like I'm selling all my kit before my bulk destroys it!

 

[Drago]

Ruddy hell, my breakfast weighs more than 180lb.

 

[vickster]

Never saw this before, but looks like I'm selling all my kit before my bulk destroys it!

View attachment 360487

Is that not just for wheels? I think 82kg is the number they quote for Fulcrums too IIRC

 

[Drago]

I'm finding all this rather lardist. How are us real men supposed to cope?

 

[Yellow Saddle]

I'm finding all this rather lardist. How are us real men supposed to cope?

A good enema?

 

[Graeme_FK]

Is that not just for wheels? I think 82kg is the number they quote for Fulcrums too IIRC

It's on all parts.
All makers have to make some general recommendations on this to cover themselves.

 

[GrumpyGregry]

Sensible advice. Read the small print and you find similar from Spesh and Giant. Being my size invalidates some folks carbon frame warranties.

As Canyon almost say in their owners manual "The laws of physics are merciless and gravity is a harsh mistress"

 

[ColinJ]

I have been up to 60 pounds over that weight and never damaged any of my Campagnolo components! I am currently 10-15 pounds over that weight and my Campagnolo wheels are perfectly okay. I do treat my bike with respect though - watching out for potholes, not bumping up over kerbs, that kind of thing.

 

[cyberknight]

Maybe Campag just want skinny pro looking riders using their stuff, they need to maintain their image.

 

[Yellow Saddle]

I have been up to 60 pounds over that weight and never damaged any of my Campagnolo components! I am currently 10-15 pounds over that weight and my Campagnolo wheels are perfectly okay. I do treat my bike with respect though - watching out for potholes, not bumping up over kerbs, that kind of thing.

It is a common misconception that potholes and kerb bumps damage wheels in the long run. That's just not true.

Wheels fail in two places - spokes and rims. The spokes fatigue at the elbows and first thread and rims fatigue in a zone around the spoke holes.
The mode for rims and spoke elbows is metal fatigue and the mode for the thread failure is crack initiation. All these modes of failure are exacerbated by a combination of stress cycles and cycle amplitude. In other words, how many times in total has the spoke loaded and unloaded and, how many times in total has the rim relaxed and re-tensioned. The answer is easy - once per wheel revolution. The second part of the combined stress contributor is the amplitude. In other words, how much does the spoke/rim load/unload with each revolution. This is a function of your weight.

In one kilometer your wheel turns 500 times (circumference is approximately 2 meters). In 20 kilometers, an average commute, say, your wheel turns 10 000 times. That's 10 000 stress cycles. In one commute you jump the kerb once and hit a pothole once. The ratio is thus 10 000:2.

Conclusion: Just riding along does more damage than any other activity on your bike.

The reason why your Campag wheels have not broken is because the weight limit is a complete and utter arbitrary limit. It isn't the result of any sort of measurement, nor is it a tipping point for sudden onset of fatigue or failure.

The same amount of fatigue will set in with 10 000 revolutions at an amplitude of 80kg than would with 100 000 revolutions with an amplitude of say, 70kg.

It is the combined effect that matters.

The only time a meaningful weight limit can be put on wheels is when the wheels will flex enough with a rider of X- kilograms so that it touches the fork blades or chainstays or brake blocks. Even then, the style of riding would dictate the rider's weight.

You say you've never damaged any of your components. How do you know that metal fatigue has not started a spoke or rim crack yet?

 

[Vapin' Joe]

People tend to forget that racing bikes are designed for racing cyclists, not overweight ex golfers.

 

[Drago]

It is a common misconception that potholes and kerb bumps damage wheels in the long run. That's just not true.

Wheels fail in two places - spokes and rims. The spokes fatigue at the elbows and first thread and rims fatigue in a zone around the spoke holes.
The mode for rims and spoke elbows is metal fatigue and the mode for the thread failure is crack initiation. All these modes of failure are exacerbated by a combination of stress cycles and cycle amplitude. In other words, how many times in total has the spoke loaded and unloaded and, how many times in total has the rim relaxed and re-tensioned. The answer is easy - once per wheel revolution. The second part of the combined stress contributor is the amplitude. In other words, how much does the spoke/rim load/unload with each revolution. This is a function of your weight.

In one kilometer your wheel turns 500 times (circumference is approximately 2 meters). In 20 kilometers, an average commute, say, your wheel turns 10 000 times. That's 10 000 stress cycles. In one commute you jump the kerb once and hit a pothole once. The ratio is thus 10 000:2.

Conclusion: Just riding along does more damage than any other activity on your bike.

The reason why your Campag wheels have not broken is because the weight limit is a complete and utter arbitrary limit. It isn't the result of any sort of measurement, nor is it a tipping point for sudden onset of fatigue or failure.

The same amount of fatigue will set in with 10 000 revolutions at an amplitude of 80kg than would with 100 000 revolutions with an amplitude of say, 70kg.

It is the combined effect that matters.

The only time a meaningful weight limit can be put on wheels is when the wheels will flex enough with a rider of X- kilograms so that it touches the fork blades or chainstays or brake blocks. Even then, the style of riding would dictate the rider's weight.

You say you've never damaged any of your components. How do you know that metal fatigue has not started a spoke or rim crack yet?

Soooooooo...what you're saying is avoid potholes?

 

[Tin Pot]

People tend to forget that racing bikes are designed for racing cyclists, not overweight ex golfers.

Heretic!

 

[Tin Pot]

Is that not just for wheels? I think 82kg is the number they quote for Fulcrums too IIRC

It's on all parts.
All makers have to make some general recommendations on this to cover themselves.

Yes, I'm fitting shifters.

Of which will bear zero body weight of course. Nevertheless, I'm sure my warrantee is invalidated by being fat.

 

[Yellow Saddle]

Soooooooo...what you're saying is avoid potholes?

Nooooo....what I am saying is that everybody thinks their spokes break because of potholes. It is not that.