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Bike weight vs. rider weight(26 posts)

Bike weight vs. rider weightErik W
Apr 11, 2001 9:03 PM
As far as things like making climbing easier, is losing weight as a rider equal to shedding pounds off your bike? For example is losing one pound off yourself equal to taking one pound off your bike? Is there some ratio to that. One pound off bike equals three pounds off rider? Or does it not work that way at all.
Is this a Muti-Level Marketing Scheme? Or a Test of our Buzz?gimmeaminute
Apr 11, 2001 10:39 PM
'Come on, Dude. (ENTER sound of bong bubbling) What if my bike bumped up the hill on helium protons then became a gravity wave? Answer: It really doesn't work that way. All mass lost is relative. (stay with me, you missing links) A rider on a say, 13lb bike, does not have an advantage by virtue of his presumably lighter bike. Eddie Merxxxxxxxxxx could have creamed us on a given course, regardless (nearly) of our advantage in weight. The advantage is only relative to yourself. Your choices are 1. go on a MLM diet de jour and drop a couple (15?) of pounds, or 2. you can grift Shimano and Campy into grinding monel,inconel, byrillium, titanium and skunk werks materials into trick parts. Why not? Knock out that second mortgage and get the bike 'o your dreams. Choose your misery:

Be a fat guy riding a fat bike = 1
Be a fat guy riding a skinny bike = 1
Be a skinny guy riding a fat bike= 1
Be a skinny guy riding a skinny bike= 1

Don't see the logic? Don't sweat it, you'll catch up in 25M years or so.

If Socrates was a road biker, what would he choose?
Very sarcastic responsechrisbaby
Apr 12, 2001 5:57 AM
You need not be so sarcastic. You also claim to be very logical (are you vulcan?) but I think the guy raises a valid question. So here is my spin on it.
All things being equal here...
If you are one of those guys that has about 5% body fat (lucky bastard!) then losing a pound off your body may not be such a good idea and may not make you go faster. Any weight loss here will be muscle mass. If you have a cyclists distribution of skeletal muscle, then most of your weight and muscle is in your legs. Losing musce mass in your legs could, but not necesarily, compromise your strength-to-weight ratio. In this case, it would be good to shed a few grams off the bike to help on the climbs.

If, however, you are a fat bastard (like me!) then you should lose the weight off of your body first.

To answer the original question: There is no formula that I am aware of.
you're being too kind...JohnG
Apr 12, 2001 7:10 AM
This guy's post is stupid and insulting!
JohnG
I disagree. Certainly moving less mass against gravity isbill
Apr 12, 2001 7:26 AM
moving less mass against gravity. But, at what relative cost? I think that the poster's ratio idea may reflect some lack of thoughtul consideration of different body types with different strength to weight ratios and absolute weights vs. relative weight loss in an effort to simplify the equation, but, you know, it's sort of interesting to think about. Just throwing in the variables is an exercise -- lighter weight of a bike (maybe) equals more energy lost through flexing, etc.
Ok, I'll pack 'em lighter this time......gimmeaminute
Apr 12, 2001 11:55 AM
No claim to logic here, but the issue is relationship in a formula. My answer/guess/surmise is that rider weight and bike weight relationships are equal because you can only be/have one at any given time. The relationship probably has a formula, but getting everything to fit nicely, well?

Back on Earth, for the average Joe, I'd agree with losing the body weight. As for the bike, don't sweat it too much.

Your power/weight ratio thingy could develop into the pie.........
Face It....grz mnky
Apr 12, 2001 1:41 PM
...you don't know jack sh!t about what you're saying in the technical arena and you pass of your intuition as some $0.10 theory.

When called on the carpet you bluster and insult - if you could only see how funny this looks.
You poor boy, Giiz mnky, you don't have many friends, do you?gimmeaminute
Apr 13, 2001 10:50 AM
Except the few that fawn for your "advice" and opinion.

Plus, you are an exceptionally easy mark.

Playing with you is like playing fetch with a dog.

And why is it taking you so long to catch my changing screen names?

Fetch.....
Over the Topgrz mnky
Apr 12, 2001 9:25 AM
Hey, sarcastic and cynical responses are my department! Actually, I try to save it for the truly moronic which the original poster's question is NOT. No, the truly moronic is Gimmeahit's and I didn't even provoke him. Amazing.

The critical difference is between live weight and dead weight. Weight of the rider is live weight since it can be used as leverage on the cranks. The bike as a unit is dead weight and contributes nothing. The rider plus the bike is a system as a whole and F=ma applies as always and the effects of rotational inertia. Ultimately it comes down to the strength of the rider and may be best understood with the following example: a strong skinny guy on a light bike can usually climb better while a strong large guy (not fat) on a light bike can usually sprint better. I haven't come across a generic relationship yet, but the problem could be worked out with analysis using energy and power. A 150 lb. rider on a 30 lb. bike is not the same as a 160 lb. rider of on a 20 lb. bike. An additional factor is the loss in efficiency in getting power to the pavement.

Bottom line: shedding weight off the bike is a very good thing with the wheels being the best. Getting weight off your body is good, but not at the price of power.

Pass the bong Beavis.
yup yup yupjunebride
Apr 12, 2001 9:45 AM
"Getting weight off your body is good, but not at the price of power." - Grz Monkey

listen to the monkey!! :)

-jb
All relative....gimmeaminute
Apr 12, 2001 1:17 PM
Still, this power/weight thingy may prove useful. Can you convert it into a rule of thumb? I'm stumped.

Eeehhrr. Need a light?

It would have been funnier for you to be Beavis. At least we are partners in one sense. Pass it back when you are done, Butthead.
As you saidErik W
Apr 12, 2001 2:53 PM
"The advantage is only relative to yourself". Which is what I was asking (granted not in the clearest terms). The question only pertained to oneself and ones own bike. On this board I've seen many posts about taking every gram possible off ones bike. I've also seen posts about riders shedding weight, claiming that is more important then a light bike. But is it the same thing? Is what I was asking. Of course I understand it's not as simple as that, with regards to strength to weight ratio and the general shape of the rider etc.
As you saidgrz mnky
Apr 12, 2001 3:00 PM
Ignore Gimmeahit, he's a gnat on the a$$ of humanity. He knows not of what he speaks, but thinks otherwise. You have an excellent point and checking out the website mentioned by Doug S. is a good start.
He knows not of what he speaksgimmeaminute
Apr 13, 2001 11:04 AM
Gnat on the,(well, we know) of humanity. Man, that was weak! Right up there with "throwing the raw prawn". Did you get that from "Platoon" or someother he-man source? I'm not going to go into your Chinese proverb, but come on, get some creativity.

If you've ever seen "Barfly", just see yourself as the young bartender/barback and me as Bukowski.

I'd call it the most rational comparison.
to go faster, add lightness -- to a pointDog
Apr 12, 2001 6:11 AM
Lighter will be faster up hills, until you get to the point of interfering with function, whether you or your bike. To quantify, go here (one of my favorite websites): http://www.analyticcycling.com

However, if you get too skinny and lose muscle, or are energy depleted, etc., of course you will lose power.

If you put bike parts on that are flimsey, unreliable, don't function as well, or make you very uncomfortable, you may well be slower. For example, I love the concept of the Speedplay X/1 pedals. They are roughly half the weight of most other pedal systems and easy to get in and out of. But, after trying them off and on for at least 8,000 miles, I just can't get used to them, and they seem to put strain on my lower legs. This ultimately slows me. So, I tried one of the next heavier systems, Campy Record Profits. Much more stable, but the darn things refuse to let me clip in far too often. This is not a problem when clipped in, but when it takes me a full 2 minutes to clip in after stopping to fix a flat, I've certainly lost any advantage their relatively low weight provided. So, I'm again back to my Looks. They are extremely comfortable, stable, easy to get in and out, and very reliable. But they weigh lots. Nonetheless, I've resigned myself to them, as they probably are faster *for me -- for the riding I'm doing now*. That last part is important.

Of course, there are many other examples of low weight not working as well for the particular circumstances. Lightweight handlebars might not feel good; lightweight bottom brackets can be a chore to maintain; a lightweight 11-21 tooth cogset may not provide the low gears you need; a lightweight saddle may be ok for 50 miles, but not 200; a very light frame may be fragile or flex...

You cannot state consistently that a pound of this or that is the same or different. While weight is weight, as far as your muscles are concerned getting up a hill, it can matter where it is. Examples: Lots of extra upper body muscle mass might help you in a sprint, but will hurt you in an endurance event with big hills; any extra mass, be it muscle or fat, on your body may make you slightly more uncomfortable standing while pedaling (supporting the extra weight with your legs) or just sitting on the saddle; but, the one place where extra weight will hurt you the most may be wheels and tires -- but even here lighter is not always better -- light tires tend to flat more often; light wheels can be flimsey or less aero.

So, to answer your question, it depends.

Doug
another link, etc.; reasonable weightsDog
Apr 12, 2001 6:31 AM
Here is another link to a calculation website: http://external.nj.nec.com/homepages/sandiway/bike/climb.html

I've read several places that a respectable bike weight is 12% of body weight. Therefore, a 200 lb. rider has a 24 pound bike; 150 lb. -> 18 lb. bike; 130 lb. -> 15.6 lb. bike. This would come out a little heavy for my tastes, but it certainly would be reasonable.

Doug
I like this ideaDaveG
Apr 12, 2001 8:52 AM
That means all I have to do to feel better about my 23 pound bike is gain another 10 lbs and I'll be dead-on 12%. Food is a lot cheaper than titanium bolt kits and fancy wheels, too.
Doug, did you never work out your problem with the Pro-Fits?bill
Apr 12, 2001 7:07 AM
I gotta admit, every time I get in my Pro-Fits, I think of Doug Sloan, and I wonder what is the problem there? I wonder whether your shoes and the cleats have some sort of compatibility issue. Do you have the proper insert for the sole? That was the biggest bummer for me; I've got these pretty light Sidi's and the fairly light pedals and cleats, and I have to slap in this insert that not only raised the height from the spindle but added rotating mass. But, you know, if that's the biggest bummer, it's not but so bad.
Mine work great. At this stage in cleat wear (I don't put the miles on that you do, but I would have gone through several sets of Looks by this point), I can't say that the pedals are any harder to get into than my old Looks, although they were at first.
Doug, did you never work out your problem with the Pro-Fits?PatH
Apr 12, 2001 8:27 AM
I also converted from Speedplays to Pro-fits and had a problem with getting my right foot in for awhile. Discovered that when I steppped down on the pedal to engage I tended to put most of my force toward the instep and this caused the cleat to meet the clip just askew enough to prevent engagement. I solved the problem by consciously rolling the pressure to the outside of my foot as I pressed down and Voila! Not that much movement at all, but every time I had trouble I'd think "roll your foot" and in it went.
never made them workDog
Apr 13, 2001 5:54 AM
I bought new shoes, new cleats, and with both sets of Profits I have, I get the same problem. I've tried everything I can think of, including putting my bike on the trainer and trying things right there in the garage. The former shoes were Vittorias, and the new set is the Vittoria Blitz all carbon. Very stiff sole. Maybe it's the shoe sole shape (say that fast), but those are the shoes I like best.

They tend to be fine when they are lubed at first, but after hours in the saddle, and getting off the bike a few times, they become impossible. I give up.

I have some Look PP296, the adjustable float, and recently got some PP206, one of Look's most basic pedals. After all this pedal trying, Ultegra, Speedplay, Campy, and two Looks, I actually like the 206 the best -- one of the lightest Looks, very wide platform, 100% reliable getting in and out, secure, and relatively cheap. Amazing.

Doug
Weight effects on VO2 ....HH
Apr 12, 2001 11:12 AM
... here's an interesting question that bugs me more the more I learn about VO2max. VO2 uptake is given in units of amount of oxygen uptake per unit of body mass, typically deciliters or kg. But we all know, the only tissue that should be doing any significant uptake is muscle. Fat will use a little in the process of moving calories in and out of storage, but that's nothing compared to hammering muscles.

So it would seem to me, if you are trying to improve your VO2 max by most of the normal methods of measuring it, that losing bodyfat would accomplish that goal to some degree.

But I can see a couple of other benefits to the fat loss. One is less blood flow needed thru all the blubber, conserving energy. The other is less frontal area and body surface area, reducing drag, which is the worst culprit robbing energy from us at any significant speed.

I have to vote for getting rid of fat first, at least until you get somewhat below the government guidelines for ideal bodyfat. An adult male in the 5-7% range might do well to look elsewhere for weight savings.

Sez the guy with the 40+ pound bike who's lost about 8 pounds of fat since January, with plenty more to go in both departments.
sureMidCal
Apr 12, 2001 11:45 AM
Although fat certainly robs us of speed, particularly up hills, a bike can make quite a difference. My time up that large hill (2,500 foot climb) on the Milano (28 pounds?) was about 20 minutes slower than on the EV2 at 15something pounds. Of course, there are gearing, geometry, and rolling resistance issues, but the difference in weight of the bike along that magnitude does make a big difference.

Also, the smaller you are, or the lower your power, the more the bike weight will matter.

The VO2 max determinations that are a function of body mass I never really understood, either. I realize it would make a huge difference up a hill, but on flat ground, not much. Weight is not a linear function of drag. Is there an absolute measure of oxygen uptake?

I've seen some pot-bellied riders who could really fly on the flats. Their power to drag ratio can be enormous. But, first hill...
re: Bike weight vs. rider weightBart
Apr 12, 2001 10:18 AM
Lose the fat first. You can then strenghten your legs and/or get a lighter bike.
My point was...Erik W
Apr 12, 2001 2:22 PM
I hear a lot of people say they are trying to shave every last gram off there bikes, usually at great expense. I also hear a lot of people say who cares about the bike, you can always lose weight yourself instead. My question really was, are they really the same thing?
My point was...tr
Apr 12, 2001 3:36 PM
I think the answer is no. I also think Doug Sloan's response is excellent on the weight issues of the bike and/or person.
Sense of satisfactiontommyb
Apr 12, 2001 7:17 PM
In the 12 years that I have owned my current bike, I have gained 25 pounds and have since lost 20 of them. I feel a lot better, the bike feels the same. I also have a sense of satisfaction having lost the entire weight of my bike that the purchase of a few titanium doo-dads would not remotely match. And since I feel better, I ride better. I've never ridden better as a result of buying new, lighter water bottle cages. As far as objective performance measures go, my 40k time is within a few minutes of 1989's time, when I weighed about the same as I do now. So, as I loose weight, I'm at least not aging any faster than my bike.