Road Cycling - Is weight lost from the bike different from weight lost from body?

Speed freaks are obsessed with taking every spare gram of weight off their bike. I was wondering if there is a difference between, lets say, a pound of fat lost from your body, versus a pound of weight lost off your bike, in terms of speed and acceleration. Like, for example, would 1 pound off the bike be equivalent to.... 10 pounds from your body? Or does 1 pound always equal 1 pound, no matter where its coming from?

I believe the myth goes 1# off the bike = 10# off the body. It makes sense... You've got to factor in lean muscle mass and core body strength to the equation. I think your fitness allows you to take your bike as far as you like...

And it sure is cheaper to lose a pound off yer' gut than off yer' bike $$$...

Mike

In terms of speed it depends where. Taking a gram off the frame should be the same as taking a gram off of your stomac while seated. While climbing though, you have to hold up the gram in the air in addition to carry it up the hill (so taking it off you will yeild a better performace benefit)

A gram of the wheels will go a long way because the wheels spin (the exact benefit depends on the change of the moment of inertia etc...)

The same applies to you legs, they go up and down so much that taking some weight off of them will reduce the force required to pedal more than if you just took that gram off of the frame.

hm... i think it depends on the kind of riding.

for hill climbing i think it should be close to 1-1 as the total weight is the biggest factor to overcome.

on flat ground i'm not sure, but something near 1-10 sounds ok.

as to Hawkphoto's comment about more muscle, that's not the way i interpret it --- i interpret it as pound of FAT lost compared to lb on the bike... although obviouly if you loose 10 lbs you are likely to loose a small amount of muscle too...

There is a difference between suspended weight (ie you or the suspended part of the bike) and unsuspended weight (on the bike), but Im not sure what the effective ratio is.

For weight take off any part of the bike, I think all you need do is compare the inertial moment of each gram, and the ratio between these is exactly the ratio of weights that you are interested in. (Calculating the moments could be quite complicatied, especially for parts that do not oscillate perfectly or do not go round in circles).

I have no scientific formula to impart. However, in general, assuming some measure of an overweight condition on the rider, loss of weight, if done properly should also result in increased fitness. If you lose the weight off the body by proper nutrition and appropriate exercise, the remainin weight should be also more fit (more and better muscle and less fat.)

Wieght lost from the machine itself doesn't contribute to the machine's "fitness." Though it is argued that less power from the rider would be necessary to propel it.

True, weight carried requires power to carry it no matter whether the weight is on the rider or the machine. It just seems to me that weight off the rider, within limits of course, is both cheaper to achieve and yeilds more performance benefits than the same weight taken off the bike. IMHO

maybe also consider the increase in rolling friction caused by a heavier body. 10 pounds on panniers on a bike increases rolling friction alot, while 10 pounds on a BOB trailer doesn't increase it by much, but mainly only increases the inertial mass.

i dunno... it seems pretty complicated to me.

one is permanent and the other isn't. A 16 lb. bike will always weigh 16 pounds no matter how much you eat.:D

are we talking about lost fat or lost muscle (wasting from atkins diet for example) -i would also think that it is correct that the weight that directly touches the ground (wheelset) slows the whole thing down (think a heavy kevlar vs. a lightweight model)

i personally think that it is all acedemic because any weight would show itself more during inclines, actually help increase speeds during the downhills and be almost negligible on flats.

i like to think that i can train myself to overcome such differences.

i have had fast times when i am very light but tend to burn out faster (in successive rides) when compared to a higher weight (5-6 lbs)

if my big gut get in the way then i can't get 'aero' as well. does that count in our discussion here?

I found that the people most concerned with weight on their bikes in the shop I worked in were the ones that could most stand to drop a couple of pounds themselves and had too damn much money. Hopefully, it's just that one shop. I've always tried to remove weight from myself first, and the bike second, because of the financial end of things. I think the guys that obsess over grams are looking for psychological edges, though. When you're that light, bike or body wise, you're trying to psych yourself up or the other people out.

Originally posted by ImprezaDrvr
I found that the people most concerned with weight on their bikes in the shop I worked in were the ones that could most stand to drop a couple of pounds themselves and had too damn much money. Hopefully, it's just that one shop. I've always tried to remove weight from myself first, and the bike second, because of the financial end of things. I think the guys that obsess over grams are looking for psychological edges, though. When you're that light, bike or body wise, you're trying to psych yourself up or the other people out. Yeah! Besides there is scientific proof that the dynamic vibration and oscillation coefficient of fat is 36.73204 times that of lean muscle, and if said resulting moment of inertia of fat is 36 to 58 degrees out of the plane of the vibrating momentum of the bicycle, at a speed at or above 2.487 meters / second,CATASTROPHIC FAILURE results. Studies are still being conducted to see if the failure occurs first to the ride or rider,as the result is always found as an unidentifiable pile of poo and twisted metal in the middle of the road.:)

My 2cents... Don't know what the technical terms are called... But, yes to your question with conditions. :) Dropping weight from moving parts on your bike or body would be realized in speed, climbing, distance and cardio. However, loosing weight in stationary items, such as handlbars, stem, seat, bottles, cages won't be descernable but would have a distance affect.

I have a lot of muscle mass for my size. I am working at loosing some and redistributing muscle. I've noticed the difference over the last month in my ability to climb. And, it's also affected my golf swing in a temporarily bad way :(

Weight off the bike yields a (extracting statistic from bodily orafice) 20:1 perceived improvement to the rider, compared to weight lost from the body.

Originally posted by Garbear
However, loosing weight in stationary items, such as handlbars, stem, seat, bottles, cages won't be descernable but would have a distance affect.

:( Ok, so the downtube front shifter on a well known tour of France riders mountain stage bike is all in his head? Just one example of many.

Originally posted by pokey
Ok, so the downtube front shifter on a well known tour of France riders mountain stage bike is all in his head? Just one example of many.

I used the term "discernable", verses "measureable" and I don't think shifter weight is discernable even by a professional racers. Who ever your referencing is considering every gram and aerodynamics because he can and his career depends on him doing everything possible to win. With right instrmentation, maybe shedding grams is measurable over scientific test track conditions, I don't know.

I was just told that Mario Cipollini went through 40 frames before settling on what "felt right" to him. I can only imagine how many LA went through to "feel" right before racing. For a Pro, logic says loose any and all weight where possible, including shaving ones legs...They go to the extreme to protect their position.

The question was:
Speed freaks are obsessed with taking every spare gram of weight off their bike. I was wondering if there is a difference between, lets say, a pound of fat lost from your body, versus a pound of weight lost off your bike, in terms of speed and acceleration. Like, for example, would 1 pound off the bike be equivalent to.... 10 pounds from your body? Or does 1 pound always equal 1 pound, no matter where its coming from?

The difference between my CR 10spd double crank @632grams compared to CR 10spd carbon crank @500grams is next to nothing and after 30yrs or riding I couldn't tell the difference. But, recently I went from a 19.2lb bike to a 16.8lb, and I can feel some difference, especially on long rides at the end in a climb.

pokey, document and prove this further:


Yeah! Besides there is scientific proof that the dynamic vibration and oscillation coefficient of fat is 36.73204 times that of lean muscle, and if said resulting moment of inertia of fat is 36 to 58 degrees out of the plane of the vibrating momentum of the bicycle, at a speed at or above 2.487 meters / second,CATASTROPHIC FAILURE results. Studies are still being conducted to see if the failure occurs first to the ride or rider,as the result is always found as an unidentifiable pile of poo and twisted metal in the middle of the road

Originally posted by ImprezaDrvr
pokey, document and prove this further:
[yada yada yada deleted]


doooooood, if you didn't recognize the sarcasm dripping from his first post, you probably won't catch it in his proof, either.
:D

A little perspective: unless you are serious racer, don't sweat your body weight too much. If you're getting in your base miles, and eating in a relatively healthy fashion, your body will find it's optimum weight. Sure, you might lose a few pounds by dint of fanatical discipline, but you might pay for it in increased weakness. Beyond a certain point, weight loss needs to be monitored by trained coaches and/or doctors to prevent catabolic wasting.

OK bike weight can make a difference. I think the difference between an mid range shimano group equipped bike and a dura ace equipped bike is about 2 lbs. Climbing is power to weight ratio. So if the cyclist and bike weighs 200 lbs (I picked this number because the math is easy), he will climb about 1% slower on the "cheap" bike then the "expensive" bike. On a 5000' climb that would be 50' or at a 10% grade about 500' back. That could be a decisive difference in a race. Remember, weight really only enters in drastically on climbing and accelerating. On flats, the effect is much less.

Another thing is this. You can spend say $2000 more dollars and shave 2-3 lbs off of your bike. And you might see a difference in performance and you might not.

However, most people are recreational cyclists. Most cyclists can afford to lose 10, 20, 30 or even more lbs. The best potential place to lose weight is off the rider and not the bike.

The other thing is that the engine is also important. The engine is the rider. The more training you do, the stronger you get. When I am in a group with strong riders riding hard to drop each other, I have never seen a case where putting the strongest rider on the worst bike in the group would have made a dang bit of difference (assuming of course that it fit).

As for weight on the bike, on certain places, like rotating parts, losing a lb can have a larger effect then losing weight on the frame. Of course, there is a downside. Shaving so much weight that wheels collapse or you get piles of flats is counterproductive. One breakdown will cost you far more time then shaving that little bit weight will ever save you. That is why you don't see 10 lb bikes. I suppose that they could make them but the resulting unreliability just does not make up for the fractional gains.