Is weight (or lack of) the be all and end all?

rc856

Hi folks,

Recently I've read a few topics about forum members wanting advice on what expensive framesets or wheels to buy and it always make me daydream about me being in the same position with a dream bike.

In my mind, without question, I'd be getting the lightest frame/lightest wheels possible but a lot of the time I see the Cosmic Carbone wheels recommended which are heavier than a few others. I look at wheels I'd like to upgrade to but for quite a lot of ££££s more, they're not much lighter than my current Campag Zondas.
Makes it the more confusing if I was to upgrading wheels!!

And I was suprised to read that one of my dream frames, the Colnago M10, weighed in around 1500g.

So..might be a daft question to some but I was just curious as to whether there was a lot more to it than just getting the lightest wheels etc?

Thanks :?

Down the Road

No.

Best frame I raced was a Look 486 the frame weighed in at 1500g but it went uphill like stink. Possibly better than a lot of lighter weight frames of today.

Raced it with wheels of about 1800g and lost out nothing anywhere.

Power Transmission is more important than weight and I know the best way to explain it using the 486 frame.

But that's another story

inseine

Whatever the answer to your question no way is the Colnago 1500g. With forks and seatpin maybe. I thought it was meant to be 850g!

markos1963

How long is a piece of string?
The problem(or not if you like to have lots of bikes) is that there isn't such a thing as the 'perfect' bike. The fastest bikes on the flat are TTers but are amongst the heaviest racing bikes on the road. If you are riding in the mountains then a TT bike isn't going to cut it, light weight(especially wheels) are the priority.

desweller

On the flat: Drag vs Power
Ascending: Weight vs Power
Descending: Drag vs Weight (and courage)
Acceleration (not often relevant except in sprints): Weight and Drag vs Power

Power can be your endurance power level (ascents and TT) or your short-term power (sprints). Weight is largely driven by the rider, as he/she is always going to be far heavier than the bike.

Drag mostly varies with your position on the bike. Wheels like the Cosmic Carbone are low drag, but the deep rims required to achieve the aerodynamic gains come at the cost of increased weight.

rc856

inseine wrote:

Whatever the answer to your question no way is the Colnago 1500g. With forks and seatpin maybe. I thought it was meant to be 850g!

I was in no way quoting that as fact. I think I read it in the 'frame for 3k' thread.

And thanks for the answers

galatzo

My latest bike weighs 6.7kg including pedals and right now it's a joy just picking it up I've not ridden it enough to know if I like it yet but I do like lifting it up
I know they're for riding but there's something very satisfying about lifting a light bike up.

Wappygixer

To most people weight wont make any difference really.You could put Cav on a 25lb bike and he would still be faster than anyone of us even if we were riding sub 15lb bikes.
Its a mental thing I think and its nice to have something a little special.
Buy what you like and can afford ,if you get complements then so be it if not you should be happy inside, if your not your either skint of didn't do your research first.
I'm always happy on my Kuota and cant wait to get it back on the road.It weighs in at 16lb and I love it, even though I'm slow.

bendertherobot

I have two bikes.

A Focus at about 9kg and a Lemond at 6.9kg

I remarked to the Mrs that commuting on the Lemond (40 miles a day) is pointless as it's just too easy whereas the heavier bike is, well, hard work.

There may be many reasons for this, of course.

cougie

No point in having a light bike if it's floppy. And bear in mind total weight of bike plus rider. For a heavy rider the difference in weight between decent bikes would be pretty minimal.

MaxwellBygraves

No, but it helps...

flanners1

Makes no real difference in my book, nice to have a light bike but it is how it rides, usually up and down; as most if not all cycles and BSO's will feel ok-ish on the flat.

Most modern carbon frames at a 'real world' price point are in the 'zone' of acceptability weight wise. Weight in the wheels and where the weight is placed is more important to me.

All the weight saving and stiffness claims we get bombarded with year on year reminds me of washing powders and their continual claims. :roll:

Grifteruk

IMO a lighter bike does make a difference, both physically and mentally.

Improving my climbing has been a long term goal and I know that my lighter bike makes a big difference on the steeper sections, to the point when Saturdays indulgence on my best bike showed me just how much easier it is. My winter bike Is a few kgs heavier than my best bike, and when going uphill on Sat on the best bike I couldn't feel my back wheel. It made me feel much better and I got up the hill faster.

I'm certain others will disagree, but it works for me.

Monty Dog

It also depends on rider weight and riding style too - making a frame too stiff can be counter-productive for lighter riders because the whole bike just skips and jumps around on anything but a smooth surface - might not be noticeable in general riding but in a race when someone puts the hammer down it can be pretty frustrating to have to back-off - I race on an older ti carbon frame purely for that reason.

inseine

it can be pretty frustrating to have to back-off - I race on an older ti carbon frame purely for that reason.

I had an one of the early Alan carbon tubed/ali lugged frames and I really had to back off a couple of times in sprints because it was so whippy, but I know what you mean about super stiff frames skipping about especially if you overinflate the tyres. I don't find super light modern bikes more likely to skip about though.

what brakes

I have 2 identical frames. One is built up with light wheels and components while the other (training/commuting bike) is built up with heavier wheels and tyres, heaviers components etc. Im noticably faster on my lighter bike! and it feels easier on the hills and quicker to accelerate.

So for me yes weight does play its part!

Some will bang on about the rider losing weight will have a bigger difference but maybe riders dont want to lose weight and look like a stick insect! So the next best thing is a lighter bike!

vorsprung

Weight isn't as important as having a comfortable, well fitting bike

Essex Man

Unless you constantly cycle ruthless climbs, I don't think you'll "notice" a 1-2 kg difference, it's a low % of the overall bike+rider weight.

dennisn

You ask if all there is to it is buying light wheels? You've got to be kidding? Of course there's more to it. Even thinking that you can buy big speed and power buy shelling out more money than the next guy is lunacy. It's a bicycle and wheels, nothing more and it won't move so much as an inch on it's own. As a matter of fact a bicycle can't even stand up on it's own without help. So, don't look for the bike to help you go faster, look to yourself and forget all these weight wennie schemes and promises of podium finishes with this or that bike and this or that wheel. You're not going to gain any speed and power at all until you start developing legs, lungs, and heart.

night_porter

what brakes wrote:

I have 2 identical frames. One is built up with light wheels and components while the other (training/commuting bike) is built up with heavier wheels and tyres, heaviers components etc. Im noticably faster on my lighter bike! and it feels easier on the hills and quicker to accelerate.

So for me yes weight does play its part!

Some will bang on about the rider losing weight will have a bigger difference but maybe riders dont want to lose weight and look like a stick insect! So the next best thing is a lighter bike!

I believe the weight difference is minimal, I am guessing that you don't try and race on the commuter? Certainly a lighter bike will be easier to go up hills but conversley it must be easier for the heavier bike to come down hills?

My own experience is my commuter bike and my journey to work. In the last 3 months I have lost 20 kilos and it still takes roughly the same time for me to ride to work. Perhaps the easiest way to prove the weight thing is to ride a jounrey as fast as you can. Then repeat the journey with some extra weight and see if it has made a difference!

You may be surprised at the results.

gethmetal

"I believe the weight difference is minimal, I am guessing that you don't try and race on the commuter? Certainly a lighter bike will be easier to go up hills but conversley it must be easier for the heavier bike to come down hills? "

This is twaddle. Acceleration due to gravity is at a fixed rate and is governed by air resistance. Extra weight may have some effect on how long you'd keep rolling once a hill flattens out, but not at the speed you'd descend at.

As for the OP's question, I have been trying to remember a sentence from a book on cycling I read years ago. It goes something like this...

"There is a bigger difference between the prices of regular and performance kit, than there is in the actual difference it will make to the rider."

rolf_f

gethmetal wrote:

As for the OP's question, I have been trying to remember a sentence from a book on cycling I read years ago. It goes something like this...

"There is a bigger difference between the prices of regular and performance kit, than there is in the actual difference it will make to the rider."

Bit of a statement of the blindingly obvious in some respects that! Basically, otherwise known as the law of diminishing returns. Governs pretty much everything that we spend money on. eg how much nicer is a £5000 bottle of whisky than a £50 bottle etc etc. Lucky for the manufacturers we accept this - otherwise we'd all be on £500 bikes which would pretty much do everything our more expensive bikes do only about 20 seconds slower in 4 hours

gethmetal

Blindingly obvious to you maybe.
But there do seem to be some who think that spending more money will have a proportional effect on performance, which is bollocks.

inseine

While I understand the science the reality isn't always so. When I bought my latest Giant TCR I got a complete bike (which I don't normally) it came with pretty basic wheels and I was thoroughly disapointed with the ride. Changing to a set of 1300g wheels transformed it. Since then I've changed everything else but the it was the wheels that made the differnence.

rolf_f

gethmetal wrote:

Blindingly obvious to you maybe.
But there do seem to be some who think that spending more money will have a proportional effect on performance, which is bollocks.

Probably should have said 'ought to be blindingly obvious'.

Entirely agree - please see edit to my previous post that I was just making re £500 bikes

Personally, I don't mind spending loads on bikes but I do do it in the full knowledge that it won't really make me faster......

gethmetal

Rolf F, off topic, but how is the SAAB running these days?
They're getting rare now...

Chris James

gethmetal wrote:

This is twaddle. Acceleration due to gravity is at a fixed rate and is governed by air resistance. Extra weight may have some effect on how long you'd keep rolling once a hill flattens out, but not at the speed you'd descend at..

Yes, you accelerate at the same rate due to gravity, however your air resistance is governed by your frontal area, which would be the same on the heavy and light bike if set up the same.

So the same slowing force is applied.

But it is applied to a larger mass in the case of the heavier bike, and since

Force = Mass x Acceleration

and the force of air resistance is constant in both instances, then the large mass will see a smaller deccelaration due to wind resistance.

So, far from being 'twaddle', the previous guy was right, heavy bikes / riders go uphill slower and downhill faster. Which is just common sense anyway.

rolf_f

gethmetal wrote:

Rolf F, off topic, but how is the SAAB running these days?
They're getting rare now...

MOT'd on Monday - no advisories 8)

Did have a problem with the exhaust blowing though. First bloke tightened and replaced manifold bolts, second garage adjusted the tail pipe. Second garage then, when I went back and said it still sounded blowy, finally found the crack and welded it!

You're right on the rarity though - half our little Saab group have abandoned the classic 900 cause this year and bought Vauxhalls instead

rolf_f

Chris James wrote:

So, far from being 'twaddle', the previous guy was right, heavy bikes / riders go uphill slower and downhill faster. Which is just common sense anyway.

Oddly enough though, a single unstatistically meaningful experiment easily proves the converse

Last week, I dropped the car off at the garage and biked in to work a 10 mile, mainly downhill route. The steed was my MTB with draggy brakes. It took about 42 minutes. I returned in the evening on a 7.1 mile route with a very long, steepish drag. That was about 36 minutes and I was in a hurry.

I repeated the trip on Monday with a lighter (28lb as opposed to 32lb for the laden MTB) touring bike (with all new running gear). The downhill took a good 6 minutes less. The uphill return was almost identical in timing.

Therefore the heavier bike took the same time to climb but was slower on the descents. I rest my case (seriously, I was surprised about the climb.....)

Chris James

I suggest you repeat the experiement on the same bike, adopting the same position on it, and put weights in your pockets.

Heavier descends faster, all other things being equal.

Perhaps, as a mechanical engineeer, I have more faith in the science!

It is fairly marginal though. Likewise for a 80kg bloke riding uphill on a 8kg bike or a 12 kg bike the difference in required power is only 4% but you'd get the impression it was about 50% from some reviews.

I guess that shows that the main difference between light and heavy bikes is mental.

The record for my local hill climb, Jackson Bridge route was held for many years by Chris Boardman.It might still be. I can't imagine his bike from 20 years ago would have been very light compared to modern day steeds, but it didn't seem to slow him down much on an extremely steep course!

(mind you, I do blame my heavy bike when I grovel my way up the course!)

cougie

From experience I can tell you that heavier bikes/riders will go faster downhill than lighter combinations.

This assumes that the rolling resistance of the tyres is roughly equal - a fat dude on a MTB with tractor tyres isnt going to come whizzing past Contador on an alpine descent any time soon.