The come down

DonDaddyD

So, after a few weeks of meetings, interviews, website launches and a week annual of leave (which included actually working for work) I finally got to commute on bike to the office proper.

As winter is clearly looming and seeing around 6.00 - 6.30pm a Dolan Mythos (yesterday at Battersea Park train station) in what looked like the hands of a thief, I left Karen, my Kharma at home and I put some old tyres on Donovan (my aluminium Giant SCR 3) and set upon my journey to work.

Things I noticed after a 7mile commute:

*Carbon is better than aluminium.

*Ultegra SL is a better groupset than Sora

*Fulcrum 5 wheels are more reassuring than Fulcrum 7

*My more aggressive riding position on my Kharma is more involving and comfortable than my 'upright position' on my Giant.

*I like narrow road handle bars.

*Having the back of the bike feel so low, makes you feel slower - Giant SCR frame geometry.

*There is no sudden snap in acceleration on a aluminium frame.

*My aluminium SCR frame is a power sponge compared to my carbon bike.

*Carbon is more exciting and responsive than aluminium.

*My Kuota Kharma is a better bike than my Giant SCR

Conclusion carbon makes me happy.

Seriously, I like my Giant SCR I really do but after riding a whole summer on my Kuota what the f*ck am I going to do. I can't go back, it's like going back to your first job ever when you first started working - for me that was McDonalds... :shock: Marketing job or McDonalds drive through....

Even riding at speed on the Giant was daunting, if I wasn't out of the seat trying to get to speeds I could do on my Kuota with a couple crank turns, I was slowing down because I half expected the Giant to just give up and crumble underneath me. It didn't feel safe and despite the longer wheelbase it felt less stable and sure-footed.

I really don't think I'm going to enjoy riding the entire Autumn and Winter on my Giant...

Has anyone else felt the depressing come down when switching from their best bike back to their hack...

linsen

I don't actually have a winter commuter bike but I do ride my BSO to college on a Tuesday night. I revel in the fact I will get fitter riding that than my roadie, I will not have to worry about leaving it locked up outside and I can thrash it without worrying when it will need cleaning and re-greasing. (I haven't cleaned the chain on it for 15 years - I think it would fall apart if I tried.

Had you guessed I am an optimist?

Aidy

Whilst I'm not disagreeing that carbon fibre is a nicer frame material than aluminium...

*There is no sudden snap in acceleration on a aluminium frame.

*My aluminium SCR frame is a power sponge compared to my carbon bike.

Eh?

Isn't the most commonly touted benefit of not-aluminium the fact that they tend to have some flex in them (hence why some bikes have CF seat stays). How's this supposed to soak up power?

With regards to riding position - surely that's tweakable to make you happier?

DonDaddyD

Aidy wrote:

Whilst I'm not disagreeing that carbon fibre is a nicer frame material than aluminium...

*There is no sudden snap in acceleration on a aluminium frame.

*My aluminium SCR frame is a power sponge compared to my carbon bike.

Eh?

Isn't the most commonly touted benefit of not-aluminium the fact that they tend to have some flex in them (hence why some bikes have CF seat stays). How's this supposed to soak up power?

With regards to riding position - surely that's tweakable to make you happier?

Carbon vs Alu - firstly there are exceptions to the rule. My carbon frame as a material is better than my alu framed bike. It's stiffer, lighter and more comfortable in the places it needs to be.

Carbon fibre isn't as flexible as aluminium. It's used as seat stays and seat posts for comfort because it absorbs vibration whereas alu will transmit that to the rider and the vibration is what is uncomforable.

In terms of power transfer, my carbon frame transfers power to the cranks far more efficiently than my alu bike. The groupset probably helps in doing that.

The varying frame geometry and frame size means that I'll never get the Giant to be like the Kuota...

MonkeyMonster

Hmmm... that still doesn't make much sense for acceleration. Stiffness rules for that and I had previously thought aluminium when was the stiffest out there [yes, another smut laden post coming *ahem*] So it absorbing vibration surely is down to it being more flexible.

Therefore aluminium has a better "snap" of acceleration ie doesn't eat any in frame flex.

andrewjoseph

In terms of power transfer, my carbon frame transfers power to the cranks far more efficiently than my alu bike. The groupset probably helps in doing that.

Is this a new energy source?

And here I was thinking that it was my legs transferring power to the cranks, which in turn deliver that power to the cassette and wheels.

I'm getting a carbon frame next time!

supersonic

It completetly depends how the frame are built, given the material. You can get flexy and stiff frame examples of all materials. Alu tends to be purposely built stiff to maintain strength and durabilty as the material has no fatigue limit when flexing, and repeated large flexing can cause them to fail quicker.

As a material like for like, steel is 3 times stiffer than alu, and ti is about twice as stiff (young's modulus).

The carbon layup can have some vibration damping properties.

DonDaddyD

MonkeyMonster wrote:

Hmmm... that still doesn't make much sense for acceleration. Stiffness rules for that and I had previously thought aluminium when was the stiffest out there [yes, another smut laden post coming *ahem*] So it absorbing vibration surely is down to it being more flexible.

Therefore aluminium has a better "snap" of acceleration ie doesn't eat any in frame flex.

Right, if we are comparing the very best aluminium to the very best carbon fibre then maybe so. But we are comparing the aluminium used to build my £000 Giant SCR3 to the Carbon Fibre used to build my £0000 Kuota Kharma.

Dare I say that the carbon on the Kuota is probably stiffer than the alu on the Giant.

Moreover the transfer of energy (which i would dissipate more in alu frames - but i could be wrong) isn't the sole reason why my Kharma has a greater sudden snap of acceleration over my Giant. Weight is another contributing factor, groupset, cranks, bottom bracket, wheels (I was using the same tyres). All I know is that when I want to go fast on the Kharma it's easier to do so that the Giant and the carbon helpd to do this.

greg66_tri_v2.0

DonDaddyD wrote:

Has anyone else felt the depressing come down when switching from their best bike back to their hack...

Not me. But then, my idea of a hack may not the in tune with everyone else's...

DonDaddyD

andrewjoseph wrote:

In terms of power transfer, my carbon frame transfers power to the cranks far more efficiently than my alu bike. The groupset probably helps in doing that.

Is this a new energy source?

And here I was thinking that it was my legs transferring power to the cranks, which in turn deliver that power to the cassette and wheels.

I'm getting a carbon frame next time!

No you muppet but the bottom bracket area of the frame that holds the bottom braket and crank set is a large contributing factor to the way power is delivered from the legs, to the cranks which in turn rotates the cassette and wheels creating forward motion.

The size of that area and the material its made from have developed over the years to produced more efficient ways of going forward on a bike.

_Brun_

DonDaddyD wrote:

Dare I say that the carbon on the Kuota is probably stiffer than the alu on the Giant.

You're rather missing the point of carbon fibre. It's less stiff than aluminium (yes, even that of the Giant) where the designers want it to be, such as forks and seat stays.

DonDaddyD

The comfort benefit of carbon seatstays is because carbon fibre doesn't vibrate as much as aluminium does and therefore offers more comfort than aluminium ones. I'm sure if they wanted to make carbon seatstays stiffer or as stiff as some aluminium ones they could (and visa versa).

If aluminium is so much stiffer than carbon fibre, why are the majority of TT bikes not made of aluminium anymore besides the weight saving?

I have carbon forks on the Giant.

supersonic

Old Sheldon 'stiff and flexible' Brown, rest his soul, has an interesting articel on this:

http://www.sheldonbrown.com/frame-materials.html

UndercoverElephant

DonDaddyD wrote:

But we are comparing the aluminium used to build my £000 Giant SCR3 to the Carbon Fibre used to build my £0000 Kuota Kharma.

I'd just like to say that I think both bikes were a bargain.

il_principe

Greg66 wrote:

DonDaddyD wrote:

Has anyone else felt the depressing come down when switching from their best bike back to their hack...

Not me. But then, my idea of a hack may not the in tune with everyone else's...

What's a hack bike? :?:

MonkeyMonster

I imagine you are indeed correct to a smallish degree on that carbon frame being more efficient to ride on. But don't forget that you will be adding a large degree of "eugh, not my carbon bike" [violins at the ready] and thus already be preparing yourself that it won't be as pleasurable...

I guess what I am saying is MTFU and stop blaming the tools in this case. Suck it up soldier and get on with living!

DonDaddyD

My carbon fibre bike is better than my aluminium bike.

boneyjoe

You know you must do it - put away that skimpy summer party dress till next season!

Aidy

DonDaddyD wrote:

The comfort benefit of carbon seatstays is because carbon fibre doesn't vibrate as much as aluminium does and therefore offers more comfort than aluminium ones. I'm sure if they wanted to make carbon seatstays stiffer than aluminium ones they could.

Where do you think this vibration comes from? Why do you think that carbon fibre vibrates less than aluminium?

_Brun_

Aidy wrote:

DonDaddyD wrote:

The comfort benefit of carbon seatstays is because carbon fibre doesn't vibrate as much as aluminium does and therefore offers more comfort than aluminium ones. I'm sure if they wanted to make carbon seatstays stiffer than aluminium ones they could.

Where do you think this vibration comes from? Why do you think that carbon fibre vibrates less than aluminium?

Because it's more expensive, and shiny.

supersonic

Aidy wrote:

DonDaddyD wrote:

The comfort benefit of carbon seatstays is because carbon fibre doesn't vibrate as much as aluminium does and therefore offers more comfort than aluminium ones. I'm sure if they wanted to make carbon seatstays stiffer than aluminium ones they could.

Where do you think this vibration comes from? Why do you think that carbon fibre vibrates less than aluminium?

It is not the seats stay flexing. They hardly move in the vertical plane, if at all. The material, lay up and resins can damp big frequency vibrations like buzz from the road.

sarajoy

Well, isn't it nice to know that DDD is happy with his purchase

MonkeyMonster

I know your pain though DDD, just being mean. My bro-in-law recently bought a roubaix after having a spectre for ages. He often has a critical decision to make in the morning as to which to go out on...

DonDaddyD

Aidy wrote:

DonDaddyD wrote:

The comfort benefit of carbon seatstays is because carbon fibre doesn't vibrate as much as aluminium does and therefore offers more comfort than aluminium ones. I'm sure if they wanted to make carbon seatstays stiffer than aluminium ones they could.

Where do you think this vibration comes from? Why do you think that carbon fibre vibrates less than aluminium?

Road vibration.

Look, my carbon fibre bike suffers less road vibration than my aluminium one. Unless my personal experience amounts for nothing when discussing my bikes that I've ridden that you haven't.

My alu seat post emitted more road vibration than my carbon one on the same bike. The guy in the bike shop said it would, most people understand.

My cromloy (not alu but a metal) fork on my Giant Escape M2 vibrates more than both my carbon forks.

why do they wrap some alu seat post in carbon fibre and then strap comfort on the advert - it absorbs vibrations primarily road vibration.

If you take a tube of aluminium and hit it against a wall it will vibrate and possibly wobble if you hit it hard enough. Hard still it may bend. Do the same with carbon fibre its likely to crack.

Part of the reason carbon fibre is s easy to fracture (really smash your carbon bike against a wall and do the same to your aluminium one and we'll assess the damage) is because it doesn't vibrate and disipate the energy in the way metal does.

UndercoverElephant

DonDaddyD wrote:

Unless my personal experience amounts for nothing when discussing my bikes that I've ridden that you haven't.

After the stories we've all heard about Karen, are you sure of that statement?

DonDaddyD wrote:

Part of the reason carbon fibre is s easy to fracture (really smash your carbon bike against a wall and do the same to your aluminium one and we'll assess the damage) is because it doesn't vibrate and disipate the energy in the way metal does.

I thought it was because it wasn't malleable, who knew.

supersonic

Carbon vs a hammer! And vice.

http://www.youtube.com/watch?v=-lsDXEEUlRE

http://www.youtube.com/watch?v=SDVpRSNtcPQ

DonDaddyD

MonkeyMonster wrote:

I know your pain though DDD, just being mean. My bro-in-law recently bought a roubaix after having a spectre for ages. He often has a critical decision to make in the morning as to which to go out on...

I was late to work today because of that.

Thinking about the jorney to and from work on my Kuota, but then the grey hairs I'd grow having locked it up and worrying...

Roastie

Carbon fibre is (broadly speaking) stiffer, weight for weight, than aluminium. Carbon absorbs vibration better - different issue entirely. That said, that doesn't mean a carbon frame will always be stiffer than an alu one; that is a function of design. It is also a function of the type of aluminium alloy - e.g. 6000 series, 7000 series, Scandium doped, etc.

As for the accelerative snappiness of the bike - it probably has much more to do with the wheels than the frame. Even a fairly basic alu frame can feel pretty snappy indeed with a decent wheelset.

supersonic

Cranks too, and BB interface I find has a noticable effect when stomping on the pedals. Going from a ST LX crank to a Hone was very different!

oscarbudgie

With your carbon bike are you now able to average more than 15mph?

DonDaddyD

UndercoverElephant wrote:

DonDaddyD wrote:

Unless my personal experience amounts for nothing when discussing my bikes that I've ridden that you haven't.

After the stories we've all heard about Karen, are you sure of that statement?

DonDaddyD wrote:

Part of the reason carbon fibre is s easy to fracture (really smash your carbon bike against a wall and do the same to your aluminium one and we'll assess the damage) is because it doesn't vibrate and disipate the energy in the way metal does.

I thought it was because it wasn't malleable, who knew.

From wiki:

Malleability, refers to a material's ability to deform under compressive stress; this is often characterized by the material's ability to form a thin sheet by hammering or rolling.

It's been a while since I passed my Jewellery qualification, with which you have to know the qualities of precious metals and stones. But ductility and malleability, I thought mostly applied more so to metals than any other material, which is why I didn't want to use the term in regards to carbon fibre - though this could be wrong.