Stupid question about weight

Peddle Up!

The (low) weight of a bike comes up time and again as a desirable property, but is there any point in getting a lighter bike when the rider could stand to lose a few pounds ? Is it the "system weight" that counts, or is it more complicated than that?

danowat

Weight is weight I guess, no matter where it comes from, although I'd say rotational weight (i.e. wheels) has a greater bearing on things than static weight does?

daviesee

No point.

That was my rational for getting a steel colnago instead of a run of the mill carbon.

Don't anyone burst my bubble

Oh, and I have lost 1 1/2 stone. How many bikes can cut that weight?


You do want it to be light enough to be enjoyable though.

Peddle Up!

So, any cyclist who is over their optimum weight (whatever that is!) who buys lightweight components is kidding themselves. Is that right?

danowat

kidding themselves about what?

pbt150

Peddle Up! wrote:

So, any cyclist who is over their optimum weight (whatever that is!) who buys lightweight components is kidding themselves. Is that right?

I wouldn't go that far. Lighter components in the groupset make shifting better, lighter frames tend to handle better, lighter wheels will accelerate faster etc. But there's little or no point in agonising over 100g at the cost of many hundreds of pounds unless you don't have anything to lose yourself.

(Just as a test, weigh yourself before and after a bathroom break, you'll easily lose a couple of hundred grams with #2's).

Pross

To oversimplify then most of us could lose a significant percentage of the bike weight off our bodies (when I started back I was the equivalent of about 3 full bikes heavier than when I previously rode and I have now lost one of those bikes!) but if the bike is 5kg lighter it is 5kg less overall mass.

Also rolling mass has more impact so lighter wheels can make a disproportianate difference to effort apparently but the physics is far too complicated for me. It's worth remembering that mass is only really an issue going uphill or accelerating and 'weight' is possibly overplayed although it doesn't feel like it when I ride at the moment.

balthazar

Peddle Up! wrote:

Is it the "system weight" that counts, or is it more complicated than that?

It isn't any more complicated than that. Overall weight is all that matters, functionally, and the bike's a fairly small component of that. However, there are other reasons than function to covet glitzy exotic bicycles, especially when the alternative is dieting.

unclemalc

If you are 'overweight' because of too much fat then when riding that fat is simply dead-weight, akin to riding with lard strapped to your upper body.
If you become fitter by riding regularly so that you lose fat then there is a healthy weight loss and you lose that dead-weight.

BUT as you become fitter, some of the weight is regained/maintained by muscle development, and muscle is heavier than fat, so it can become a trade off.

If you ride regularly in a manner which really tests you, then you will lose fat, gain muscle and become as fit as you need to be to do what you want to do.
When you have lost that excess flab, THEN spend some cash on trimming bike mass.

If you are 14 stone, titanium rails on your saddle will not help you up that climb...

This is personal experience - others may disagree. The lure of new kit is strong tho'.... :shock:

rake

its nice to have something nice. durability is an issue, light = replace bits more often (which cost more to boot)

rick_chasey

If you find a bike you love and enjoy riding, the excess weight on your body will fly off.

carrock

A lot of people upgrade their wheels to save weight- usually no more than 500g

However, lighter wheels often have less spokes or are less strong- I have a set of Mavic CXP22s which weigh 2kilos but are superstrong, never buckle or go out of true

I am also 16 stone- I fancy a lighter set of wheels but to do so now would be madness- better to lose a good 20 kilos and then upgrade the bike.

I was huffing and puffing up honister and newlands at the weekend, but it wasn't to do with having heavy wheels or a 9kg bike- it was to do with hauling my 16 stone up the bloody hills.....had I been on a S works roubaix instead of the base model I would have been just as slow and even more self-conscious....

danowat

carrock wrote:

A lot of people upgrade their wheels to save weight- usually no more than 500g

Really?, I saved nearly 1kg from changing my wheels.

Sure, I could shaved 1kg off my body, but I don't think it would look as good as my wheels!!

rake

they wont be as strong.

RobG100

Can't overall weight be classed into two. Useful and non useful weight. Ie Fat and your heavy bike components can be classed as Non Useful weight, and Muscle being classed as useful weight. If a riders Power to weight ratio is as good as it can possibly be, then using the lightest bike avaliable is a feasible thing to do. However Amateurs may as well use any old racing bike since a light bike won't increase your speed dramatically.

Agent57

danowat wrote:

Sure, I could shaved 1kg off my body

Man, that's a lot of hair!

Skippy2309

I am 93kg at the moment regularly take either bike up into the 30+mph range on the flat....

I am technically obease - although I have about 10% body :P


Weight is not an issue its what the weight is, fat does not help, muscle does - same with a bike no point having a super light bike that flexes and absorbs all the power you put into the pedals. So weight shouldnt be an issue more about the stiffness IMHO.



PS: I have seen some frames flexing at the chainstays when people put the power down!!

carrock

Skippy2309 wrote:

I am 93kg at the moment regularly take either bike up into the 30+mph range on the flat....

Chris Hoy is that you??

carrock

danowat wrote:

carrock wrote:

A lot of people upgrade their wheels to save weight- usually no more than 500g

Really?, I saved nearly 1kg from changing my wheels.

Sure, I could shaved 1kg off my body, but I don't think it would look as good as my wheels!!

well a typical set of stock wheels might weigh 2000g- as in the Mavic CXP22s fitted to specialized bikes in the £1000-£1500 range- and a typical set of nice aftermarket wheels for between £3-£500 weigh around 1500g- which is what most people tend to buy unless they're professional racers

So you either spent a vast fortune or had very heavy wheels to start with....

sparkman

(Just as a test, weigh yourself before and after a bathroom break, you'll easily lose a couple of hundred grams with #2's).

Just tried that one and lost half a stone.

Peddle Up!

sparkman wrote:

(Just as a test, weigh yourself before and after a bathroom break, you'll easily lose a couple of hundred grams with #2's).

Just tried that one and lost half a stone.

Waaaay too much information. :shock:

STEFANOS4784

I'm probably slightly underweight, would a heavier bike balance that out and make me quicker?

pianoman

Waaaay too much information.

Someone's been to the curry house (make mine a Jalfrezi) :P

I'm probably slightly underweight, would a heavier bike balance that out and make me quicker?

I'd have thought the heavier bike would favour people closer to the normal weight range; after all, Scott put more carbon layers into the bike ridden by Mark Cavendish than those of his teammates. Similarly, a light rider can surely make more use of a light bike because the weight is more important on the climbs.

I've seen plenty of people who I would class as "better than their bikes" and I had to laugh at a recent post on another forum regarding a TT rider huffing and puffing to the start line after their warm up - on a £5,000 Cervelo :roll: There are too many variables at play to suggest that taking 250g here or 500g there is going to make every single one of us quicker - and even then, factors like stiffness (for sprinters) and aerodynamics (for anyone who batters themselves on training rides past the 20mph mark) are surely more important.

peejay78

for hillclimbing disciplines weight is everything, and power to weight the optimal thing. there's a reason why andy schleck is thinner than the bamboo canes in my garden, and a reason why hills hurt so very much when the rider is overweight, but they can churn out 30mph+ for a short while on the flat.

CiB

I'm a stone or so overweight, but if I held off buying a lighter bike until I lost that I'd never buy it, would still be on a bike made of scaffolding. And having got the shiny lightweight I ride much more as it's more enjoyable than lugging a heavywieght machne up a hill.

It's also an unalterable fact that lighter bikes are higher up the pecking order and come with better components.

peejay78

lighter bike + lighter rider = considerable gains

lenclume

The (low) weight of a bike comes up time and again as a desirable property, but is there any point in getting a lighter bike when the rider could stand to lose a few pounds Smile ? Is it the "system weight" that counts, or is it more complicated than that?

Here's a bit about weight by the always-entertaining guys at Rivendell (admittedly they have a vested interest, as they make lugged steel bikes):

"Frame weight is 1/4 as important as bike weight, and bike weight is 1/10 as important as body weight. If you want to go fast, ride harder and more often. We're not suggesting you should want to go fast unless you're racing, but if you do, that's how you'll achieve it. You can buy a Lightspeed, but it won't make you light or give you speed."

http://www.rivbike.com/article/bicycle_ ... _materials


And this is a nice article about weight, as well, entitled "How lightweight do you NEED your bike to be...?":

http://www.smartcycles.com/bike_weight.htm

"James C. Martin, Ph.D., assistant professor in the department of exercise and sport science at the University of Utah provided some interesting calculations that make the cost of weight very clear.

He posited a 5 kilometer, 7% grade. That's a good, stiff climb. The legendary Stelvio climb averages 7.5%. He further assumed a rider who can kick out 250 watts. A 160 pound rider will take 19 minutes and 21 seconds to get up the hill. Every 5 pounds added make the trip up the hill take 30 seconds longer.

That means each added pound adds 6 seconds to the time it takes to get up this hill. That is only 6 seconds on a stiff, 20 minute climb.

So, given our roughly 4-pound range from a full steel bike to a super-light carbon or aluminum bike, the time difference up this hill would be 24 seconds from best to worst."

peejay78

i did a 3 km hill climb yesterday.

i came third, by 2 seconds. if i was 2kg lighter, i.e at race weight, i would have come 2nd.

however, i wouldn't have come first, because the winner was a national hillclimb champion.

so i can draw the line there.

24 seconds can be the difference between 3rd and 30th in a strong field.

freehub

The only good thing about heavy bikes is training, and then when you get on a super light bike you'd feel alot faster. You put a fat guy on a light bike, gonna go up hills faster, you put a pro on a light bike, gonna go up hills faster, compared to them on a crap bike.

ireland57

Any weight is worth shaving off anywhere.

The most beneficial in my view is obviously off the body as there's usually a lot more of it and, done properly, there's a health and fitness gain associated with it.

If weight meant nothing why do Formula One builders and Top Fuel dragsters (9000 hp)
spend so much time and money shedding it?

It matters heaps.

And fwiw I'm not a weight weanie.

father_jack

Cut off unwanted body parts to save weight I believe the head is the heaviest, so that'll save a considerable amount.