Bike recomendation

[Kim]

I agree with dim regards bike weight.

Assume you produce exactly the same energy output into exactly the same headwind.  Surely the bike that weighs the least will go faster?  Alternatively, in order to maintain the same speed, you must produce more energy in order to keep the heavier bike at the same speed.

Newton's first law, innit?

The only thing the extra weight will do in steady-state riding on the flat is increase tyre rolling resistance and suspension (or lack thereof) losses.  Which are negligable compared to aerodynamic drag.

It's trivially easy to demonstrate that aerodynamic improvements will make you go faster without changing weight, simply by changing your riding position on drop handlebars.

It takes a little more effort to offload some ballast (I suggest filling your panniers with bottles of water, and then pouring away the contents) - changing mass but not aerodynamic profile - but it's not rocket science.

In both cases, the change will alter the feel of the bike, which is liable to make you change your energy output.  Power meter needed for a fair test.

[dim]

Oh dear dim.

Weight has SFA to do with a headwind. 

It will slow you down by resisting your acceleration.
It will slow you down by increasing the rolling resistance through the tyres.
It will slow you down if you like to chuck the bike side to side at a frequency the bike doesn't like.
It will slow you down if you go uphill.

It will not have any effect whatsoever that is due to the wind. 

Really, how simple is this?

I was never very good at Science/theory  at school .... I'm more of "try it yourself and make up your own mind" sort of guy ....  so what I have found is that I'd rather ride a light bike in all conditions (be it wind, uphill, downhill etc) ... and I speak from my own experience

if you are pottering around, sight seeing and can't/don't ride fast ... then I suppose any bike will do (I used to own a Surly LHT and this was a really good touring bike especially if you don't care about speed or time)

people spend a lot of money to make their bikes lighter .... check the Weightweenies forum

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

[Kim]

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

With audax riding (little hard acceleration needed) a light bike will only gain you significant time on the climbs.  Obviously if all else is equal then a lighter bike is better, but depending on the hilliness of the ride you might quite reasonably decide to trade some weight for increased mechanical reliability, fewer contact point issues or better aerodynamics.

[Veloman]

........ Obviously if all else is equal then a lighter bike is better, but depending on the hilliness of the ride you might quite reasonably decide to trade some weight for increased mechanical reliability, fewer contact point issues or better aerodynamics.

Which is what I was trying to suggest in that a lighter bike will go faster, or be easier to maintain same speed, all other things being equal. And this is what I find between my two road bikes when the only difference is frame weight as I have used same wheels/tyres and set-ups are as near to identical as I can get them.

[dim]

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

With audax riding (little hard acceleration needed) a light bike will only gain you significant time on the climbs.  Obviously if all else is equal then a lighter bike is better, but depending on the hilliness of the ride you might quite reasonably decide to trade some weight for increased mechanical reliability, fewer contact point issues or better aerodynamics.

OK ... let me rephrase that ...

if you were riding the LEL this year, with the strong headwind that the guys experienced on the 2nd half of the ride, would you rather ride a Genesis Croix De Fer which weighs 12 Kg or would you ride a Giant Tcr that weighs under 7 Kg?

[grams]

There's a huge difference in the perceived speed of "light" vs "heavy" bike vs the actual number of minutes saved. Some bikes feel slow even when you're putting out the same power and achieving the same speed.

Of course perception is very important to the psychological aspect of riding, e.g. you might be less inclined to keep pedalling hard when riding a "slow" bike because it feels like wasted effort, and therefore actually go slower. But you shouldn't confuse that with reality.

[Karla]

Oh dear dim.

Weight has SFA to do with a headwind. 

It will slow you down by resisting your acceleration.
It will slow you down by increasing the rolling resistance through the tyres.
It will slow you down if you like to chuck the bike side to side at a frequency the bike doesn't like.
It will slow you down if you go uphill.

It will not have any effect whatsoever that is due to the wind. 

Really, how simple is this?

I was never very good at Science/theory  at school .... I'm more of "try it yourself and make up your own mind" sort of guy ....  so what I have found is that I'd rather ride a light bike in all conditions (be it wind, uphill, downhill etc) ... and I speak from my own experience

if you are pottering around, sight seeing and can't/don't ride fast ... then I suppose any bike will do (I used to own a Surly LHT and this was a really good touring bike especially if you don't care about speed or time)

people spend a lot of money to make their bikes lighter .... check the Weightweenies forum

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

You're changing the subject.  You were saying that a light bike would be better in headwinds.  Let's stick with this point before obfuscating it with what bike you'd like to ride on what ride.  Deal with this point in isolation.

Question: Does the weight of a bike have any effect on how much energy it takes to overcome a headwind?
Answer: No.

Examples of this:
1) Making a Dutch bike out of titanium will not make it more aerodynamic.
2) Putting lead weights down the seat tube of a TT bike will not make it less aerodynamic.

Either of those interventions might make it harder to ride up a hill, but that is a separate issue which has nothing to do with the wind.
Either of the interventions might also affect the other mechanisms I identified, i.e. handling, acceleration and rolling resistance, but none of them has anything to do with the wind.

Got it?

[LittleWheelsandBig]

Karla is right and dim is wrong. Pure and simple.

[Veloman]

So I would have managed the same speed across the Fens on LEL into that headwind had I have been on my 18kg shopper rather than my 8kg carbon jobby given that aero position and wheels etc are the same?

My experience tends to differ!

[Kim]

OK ... let me rephrase that ...

if you were riding the LEL this year, with the strong headwind that the guys experienced on the 2nd half of the ride, would you rather ride a Genesis Croix De Fer which weighs 12 Kg or would you ride a Giant Tcr that weighs under 7 Kg?

Assuming the same ergo setup and aerodynamic performance, they'd perform equally well into the headwind.

The TCR would be faster up hills, which might save a bit of rider stamina for the headwind, but experience suggests that I don't notice a 5kg difference in weight while riding (because it's such a small fraction of all-up weight).


(The real answer is that I'd notice the bikes handle differently, they wouldn't have the same ergonomics/aerodynamics and that I wouldn't make it past Spalding on either.)

[Karla]

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

With audax riding (little hard acceleration needed) a light bike will only gain you significant time on the climbs.  Obviously if all else is equal then a lighter bike is better, but depending on the hilliness of the ride you might quite reasonably decide to trade some weight for increased mechanical reliability, fewer contact point issues or better aerodynamics.

OK ... let me rephrase that ...

if you were riding the LEL this year, with the strong headwind that the guys experienced on the 2nd half of the ride, would you rather ride a Genesis Croix De Fer which weighs 12 Kg or would you ride a Giant Tcr that weighs under 7 Kg?

You're making a basic category error here, which is to try to conflate two things that are completely separate.  The headwind and the bike weight are separate issues.  The fact that the TCR is both lighter and also more aerodynamic does not mean that a light bike will be worse into headwinds, any more than it means that honing aerodynamics in a wind tunnel will make a bike lighter.  How ridiculous would that be?!

[DuncanM]

So I would have managed the same speed across the Fens on LEL into that headwind had I have been on my 18kg shopper rather than my 8kg carbon jobby given that aero position and wheels etc are the same?

My experience tends to differ!

You have an 18kg shopper and an 8kg carbon bike that share the same wheels and body position? 

It's simple to test the hypothesis that a light bike will outperform an aero bike in a headwind. You stick them in a wind tunnel and measure. It's been done, the aero bike wins. https://www.outsideonline.com/1995216/we-tested-worlds-fastest-bike-what-we-found-will-shock-you  You can also put the details of your bike and rider into a model like BestBikeSplit, and unless you are riding an alpine TdF stage, the aero bike will be faster, even if it is heavier.
Ultimately though, I assume the original poster isn't going to try to win bike races on this bike, so this is a massive diversion from the topic. Which of the aero/light bike will be nicer to ride is probably down to personal preference.

[LittleWheelsandBig]

Q - How much faster do you ride into a headwind as you empty your bidons?
A - You don't.

[Samuel D]

It will slow you down if you like to chuck the bike side to side at a frequency the bike doesn't like.

Harmonic oscillation doesn’t apply here, so do you just mean that heavier bicycles absorb more power when being thrown from side to side (honking)? I wonder how significant that effect is.

[Veloman]

Q - How much faster do you ride into a headwind as you empty your bidons?
A - You don't.

I don't but the pro peloton does everything it can to reduce the overall weight in order to maximise speed produced by their energy. I assume that, headwind argument aside, with a limited power output then a lighter bike will go faster, all other things being equal.

(Although I did once accidentally allow a bidon to depart the bike and smash the feeding bit which you may recall, along with me transferring content from one bottle to the other before realising swapping the tops would be easier: doh!)

[quixoticgeek]

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

You see, for something like the Indipac, where you're spending 14-21 days in the saddle, where each day is 16+ hours of riding. i would say that the light weight is less important than the comfort. If your light bike is so hard that you feel every stone and bump, you're going to be going crazy by the end of day 2. If it's got such an uncomfortable position that your shoulders hurt so much that after your 2 hour nap you're so stiff it hurts getting on the bike, you're going to struggle.

There's a reason that the winner of the TCR has always been on a steel framed bike. Comfort. Yes a light bike might save you 20Watts per hour climbing over some alpine pass, but that's not worth it if it makes the bike too uncomfortable to ride for 21 days straight...

J

[psyclist]

To put the bike weight arguments into perspective, there is an interesting piece of analysis on the RideFar website. In relation to the 2016 TCR route, they conclude "about 30 to 40 minutes of cycling time saved across the entire 3900 km route per kilogram saved."

Working this back down to a typical Audax event, the time savings are very small.

https://ridefar.info/bike/speed/weight/

[Samuel D]

Energy and power aren’t quite the same thing! (Applies to several commentators above.)

Speaking of bidons, Anquetil took his out of the cage and put them in his pocket at the bottom of climbs to lighten his bicycle. This counted for double into a headwind.

[grams]

I don't but the pro peloton does everything it can to reduce the overall weight in order to maximise speed produced by their energy. I assume that, headwind argument aside, with a limited power output then a lighter bike will go faster, all other things being equal.

There are simple well-defined equations for the forces acting on a bicycle in motion. Weight is not a parameter in the equation for aero drag.

On a flat road, a bicycle will accelerate to the speed where rolling resistance and aerodynamic drag exactly match power output from the rider. While acceleration will take longer if the bike is heavier, the speed reached once the acceleration phase is complete will be *exactly the same*, less whatever tiny affect the extra weight has on the bicycle's rolling resistance.

(or put more simply, on a flat road almost all of your effort is spent counteracting aero drag - whether or not there's a headwind - and weight has literally zero effect on aero drag)

[dim]

So, if you were riding a very long Audax ride such as Indipac, what would you rather use .... a light bike that will gain you time so that you have more rest/sleep time .... or a heavy cluncker that feels nice on the road, but gives you very little time to sleep?...

You see, for something like the Indipac, where you're spending 14-21 days in the saddle, where each day is 16+ hours of riding. i would say that the light weight is less important than the comfort. If your light bike is so hard that you feel every stone and bump, you're going to be going crazy by the end of day 2. If it's got such an uncomfortable position that your shoulders hurt so much that after your 2 hour nap you're so stiff it hurts getting on the bike, you're going to struggle.

There's a reason that the winner of the TCR has always been on a steel framed bike. Comfort. Yes a light bike might save you 20Watts per hour climbing over some alpine pass, but that's not worth it if it makes the bike too uncomfortable to ride for 21 days straight...

J

tyres and tyre pressure play a very important part in comfort. Fit 23 wide tyres to your steel bike and pump to max pressure .... then fit tubeless 28's with lower pressure and you will see that the wider tyres are more comfortable for longer distance, but you will be a little slower.

I use IRC tubeless on my carbon bike and there is a huge difference in comfort compared to when I used tubes. Check the steel bikes that the guys ride on the TCR ... such as the Fairlight Cycles Strael that was ridden by James Hayden who won the race.

http://road.cc/content/review/216171-fairlight-cycles-strael

it has a carbon fork and not steel ....

[Samuel D]

There's a reason that the winner of the TCR has always been on a steel framed bike. Comfort.

Doubtful (although the riders may believe that). If frame comfort drove these choices, would they ride massively stiff forks designed for disc brakes?

Fashion is the more likely reason: everyone knows that for adventure and gravel and especially Instagram you need a steel frame, preferably from a boutique builder with a slick web presence.

[DuncanM]

Q - How much faster do you ride into a headwind as you empty your bidons?
A - You don't.

I don't but the pro peloton does everything it can to reduce the overall weight in order to maximise speed produced by their energy. I assume that, headwind argument aside, with a limited power output then a lighter bike will go faster, all other things being equal.

It depends on the rider, but most riders these days use aero bikes. The only standout exceptions are a few sprinters who believe that the aero bike that their sponsor makes is not as stiff as the regular road bike (sprinters don't care about lightness).

[McWheels]

A velomobile is heavier and faster on the flat than almost anything. Point proven. To accelerate that mass takes more energy than something lighter, therefore as a holistic choice, less weight usually brings benefits, but not in aero.

[dim]

A velomobile is heavier and faster on the flat than almost anything.

but it's shite when climbing ....

most people (who are reasonably fit), can cycle 30Km/hr or a bit faster on flats when there is very little wind, irrespective of which road bike that they use (I'm not talking about hybris or MTB's etc)...

and I'm speaking from my own experience from owning several bikes

Hit the hills and this is where races are won .... 

On a long Audax such as LEL, which is 1441km long and has 11,128m of climbing, a light climbing bike will gain you a lot of time with that elevation (especially if you are climbing into head wind) .... maybe enough time to finish the ride in time?

as for headwinds, I have owned a few light bikes such as a very light Specialized S-Works, (sad that I sold it) and it's a lot faster in headwind than many of my other heavier bikes (tested on several routes with the same wind direction and wind speed)

[LEE]

A velomobile is heavier and faster on the flat than almost anything.

but it's shite when climbing ....

That's not the point you were arguing.

We all agree that heavy bikes take more energy to lift vertically.  That's agreed.  We agree.  There's no argument.

What we disagree with you about is whether weight makes a difference when travelling horizontally.

As pointed out a Velomobile is bloody heavy but you won't keep up with one on the flat, into a headwind.  How do you explain that?  It's as heavy as a Dutch Shopper or three and yet goes faster into a headwind than a carbon road bike..weird   Maybe it's not about the weight but more about aerodynamics.

There's much more going on than just lack of weight on expensive carbon road bikes.  The subtleties of frame compliance and stiffness in the correct places , the responsiveness of the wheels, the profile of the wheels....  etc They are usually an aggregation of marginal gains that result in a fast bike, uphill, downhill and on the flat. My Genesis lacks almost all these subtleties (that my Domane has).