Alu v Carbon - The Jan 2014 viewpoint

Ironlungs

Hi folks. I have searched the Boards, and I reckon we might be due an updated thread on a debate as old as the bike to work scheme.

Affordable carbon has now been around for a few years. In fact, on next year's bikes, Giant and Cube to name but two, have knocked €200 off their entry level carbon bikes. This makes the debate between high end aluminium v low end carbon more pertinent then ever.

However, there must be far more adopters of entry level carbon out there now, and with the Bike to Work in it's second cycle, there must be many more cyclists who have first hand experience of Good alu vs low end carbon.

To give an example, I can go to my excellent local bike shop tomorrow and pick up a Giant Defy 0 - Ultegra throughout, for around €1450. A very fine aluminium bike. Or I could fork out €100 more and get a the Giant Defy Comp 2, with 105.

For those of you have ridden on both types of frame - what would you do?

Idleater

Ironlungs wrote: »

... those of you have ridden on both types of frame - what would you do?

Neither, buy steel.

dave2pvd

I'd test ride both of them and see which one I prefer.

How else would you know?

Raam

Which high end alu bikes are there out there?

Lumen

I have zero carbon bikes at the moment but given the stated choices I would go carbon.

You'll probably get marginally better ride quality and less weight even with 105.

Ironlungs

<snip>

This is the kind of feedback I think would really interest people who are interested in this question. It's why I asked it - I agree that test rides don't tell you nearly enough. The trade in question is very much valid also - but Giant do very well by offering a lifetime warranty on their frames. Cube, who also really interest me as a good German company, only offer three years. It makes the buyer wonder why they won't stand over their frames for a more significant period?

In terms of aluminium - there's the likes of the CAAD 10 in this price range (regarding what is a high end alu).

Wicklowrider

I went from a high end carbon race bike to a Cannondale CaadX as a winter bike. The CaadX is nearly 10 kilos and the wheels and tyres feel like they came of a Kawasaki. I was surprised that I wasn't suffering in my usual group and when I checked my times and average speeds on Sportstracks there was no difference from the road bike. I would decide on a frame based on fit and geometry before I'd consider the material. I'll be hard pressed to swap back to a full on race bike now that I've experienced comfort ( geometry) and discs and a dry arse.

Cee-Jay-Cee

I went from a Ridley Compact to a Felt F5. I would consider both bikes mid range within their respective classes. I love the Felt, its slightly 'softer' than the ridley, more comfortable and quicker although the geometry is slightly more aggressive.

The Ridley is now my winter bike and I've been using it full time since late October. Its a 9spd Tiagra and the Felt is 105, there is little to no difference between the group sets and so the differences between the bikes comes down to the comfort and speed.

The Ridley has a slightly harsher ride which I never noticed until I bought the Felt (naturally enough) although the Ridley is a better bike for long spins. I'm doing Mizen to Malin next September and I'm torn on which bike to take.

Both have their pros and cons and both have their uses. I would hate to have to give up either but if I was forced to make a choice I would most likely keep the carbon bike.

spoke2cun

If u were to wrap both bikes up in a black plastic bag and told to lift them first and then ride them without knowing which bike u were on, would u b surprised or dissapointed at your choice?

Cee-Jay-Cee

spoke2cun wrote: »

If u were to wrap both bikes up in a black plastic bag and told to lift them first and then ride them without knowing which bike u were on, would u b surprised or dissapointed at your choice?

Wouldn't lifting them sort of contradict what your trying to do? And even if you do mean lift them and then ride them, whether your disappointed or surprised at your choice would depend on which bike you prefer and which bike you chose...so I fail to see the point of your question.

FISMA

Ironlungs wrote: »

For those of you have ridden on both types of frame - what would you do?

Buy a steel Frame!

Seriously, I had an Al GT Lotto around 2001, then a 5500, and finally a Madone. Next time, I am going the way of a high end steel frame, fork will be carbon.

dooverylittle

The 2014 canyon ultimate al are a great bike. Stands up very well when comparedto the majority of carbon frames. I am on my second. I race on Iit and train on a carbon planet x which is a decent bike but doesnt come close to the canyon.

Ironlungs

Some interesting perspectives here alright. I thought some people might go with the age old steel frames! I haven't had one since my early twenties, twas a heavy old beast. Not worth much either, but I used to lock it. It was stolen from amongst a bunch of better, unlocked bikes. Ah well! A Smokey Diamond or something like that, mountain bike. Had a Viking racer throughout my teens, steel also. Loved that bike.

I'm very interested in the perspective of cyclists who have gone from one to the other (alu to low end carbon esp.) by way of an upgrade. You may have similar specced bikes in aluminium and carbon in your sheds. What makes the upgrade worth it? I know that more expensive carbon bikes are a marvel of science, but there is now little to no cost difference between high end alu and low end carbon - carbon is achievable on bike to work grant with some change added on.

Would a good alu frame with carbon fork and seatpost such as a Cannondale, Giant or Ridley or one of the others mentioned above rival the entry level carbon Giants, Cubes, Scotts? Would the full carbon be worth the extra €100/€200? Again, I know we all have theoretical opinions on this, but I'm very interested in first hand experience.

Lumen

There is no simple "better" dimension, it depends on the design goals of the bike.

Pure race bikes will be stiff regardless of frame material.

Some of the cheap carbon frames have very nice ride quality even though they are "worse" for racing on due to less precise handling.

All other things being equal, light is always better.

dave2pvd

So what is the bike for?

My perspective is racing - either road, crits or CX. For all of these disciplines I would buy quality CF as long as the budget allows. If not, I'd look towards aluminum. Perhaps the bike would be heavier, not as stiff, not as comfortable.

If I wanted to commute, or do long distance touring, or mount panniers, or not spend too much money, I'd buy off the peg steel. I would not race on steel as long as I can afford CF.

CF is better for racing, IMO. Good frames can be super stiff, yet ride very comfortably. They don't weigh much - v important in CX. Somewhat important on the road.

The downside of CF to me is that they tend not to survive tools being dropped on them. Mind you, I've never done that. From my experience (Specialized, Giant, Bianchi), CX bikes are very strong in a crash. Conversely, I've bent and/or cracked a couple of steel frames. None of them were particularly high-end though.

Seweryn

Wicklowrider wrote: »

I would decide on a frame based on fit and geometry before I'd consider the material.

+ 1.

I can't get these threads where you are to choose material of the frame before considering the basics like frame size/fit, geometry, ride comfort, handling, looks (?), even... weight, etc.
I would put the frame material lower down the list than all the above factors.

Ironlungs

Seweryn wrote: »

+ 1.

I can't get these threads where you are to choose material of the frame before considering the basics like frame size/fit, geometry, ride comfort, handling, looks (?), even... weight, etc.
I would put the frame material lower down the list than all the above factors.

Ok, but who says frame size/fit geometry etc weren't considered first? There are threads here on lights, helmets, cranks, tires etc, but we can't have a chat about frame material?

For me, the first consideration is price point. Having seen what is available at the price point, choices need to be made. Getting properly set up on the bike is a given.

It would be lovely to phone a bike shop and tell them you want to test a M/L in about 6 or 7 different models of varying materials and geometries (test as in take for a decent spin), having been set up properly in each first, but my LBS for a start wouldn't entertain me. Therefore it's important to gather information in other ways.

This is an 'all things being equal' question, of those who have direct, firsthand experience, regarding their experiences with good aluminium as against similarly priced low end carbon.

aFlabbyPanda

I started on a steel hybrid but switched to an alu/carbon hybrid as everyone said I would faster but I wasn't. So then I switched to a road bike as everyone said I would be faster but I wasn't but I noticed the ride was harsher. So after 12 months I've decided to switch back to a steel frame (CDF) as I remember the original hybrid being the most comfortable. Comfort and robustness are my priority at the moment.

Idleater

Seweryn wrote: »

+ 1.

I can't get these threads where you are to choose material of the frame... .

Erm, but manufacturers specify the geometry of their frames, therefore it is very easy to directly compare frame material. Angles are angles and mm are mm.
I specifically chose my (steel) frame based on its identical geometry measurements to my (carbon) race bike so that I knew I could get the same position on both bikes.

Seweryn

Ironlungs wrote: »

This is an 'all things being equal' question, of those who have direct, firsthand experience, regarding their experiences with good aluminium as against similarly priced low end carbon.

It is rarely being equal, when someone compares say an aluminium Specialized to a carbon fibre Colnago, both different geometry, different wheels, etc. In that kinda case you are basicaly comparing two bikes, rather than "Alu vs CF"...

Comparing as per the topic makes sense when you get two equal bikes. I used to ride a Cannondale SuperSix (CF frame) as my first bike. Then I got a CAAD 10 (Alloy frame). These two bikes are designed and made by the same company, have exactly the same geometry, very same weight, and the only difference is actually the frame material. Swapping wheels or even tyres between the bikes make more difference to the way they ride than the difference between them with the same wheels and tyres. And by the way, for more than two years the CF bike (the SuperSix) was not ridden once and I will probably sell the frame, as the alloy CAAD 10 is as good, but slightly cheaper. It also looks better, IMO.

dave2pvd

Material is not the definitive characteristic of a frame.

It's probably down in 5th or 6th place.

Consider geometry, price, stiffness, comfort, warranty, looks/aesthetics,...

Choosing a material as a means to make you go faster is pure folly.

Ironlungs

dave2pvd wrote: »

Material is not the definitive characteristic of a frame.

It's probably down in 5th or 6th place.

Consider geometry, price, stiffness, comfort, warranty, looks/aesthetics,...

Choosing a material as a means to make you go faster is pure folly.

Thanks, but again, I don't think that anyone is pretending that frame material at a converging pricepoint is the defining characteristic of said frame. Brake callipers are way behind your checklist, but we have threads on them, frame material is still worth a discussion.

I know a bike fitter quite well, a guy who really knows his stuff. As far as he is concerned, I could buy myself a Giant TCR or a Giant Defy, two very different geometries, and he could make me equally comfortable on both. The fit is everything. He said I should have a slight speed advantage on TCR, the shorter wheelbase and more racing geometry results in more power transfer to the wheels with the same effort by me. Those two giants have matching components and kit.

FWIW, his take on alu v cf in these bikes is this. I wouldn't notice much at all as I go around a carpark - maybe nothing. But on a 2 hour or more trek around a variety of road surfaces, the carbon kills road buzz significantly more than aluminium. Thus more comfort - a lot of cyclists don't care about this as once they are sufficiently comfortable, this has little relevance. The other aspect he says is stiffness. However, as far as he is concerned, this is only relevant on higher end carbon. Where the price point between aluminium and carbon fibre converge (€1200-€1600), there is little difference in stiffness. That's his take.

But he's one man. As I said, there must be a lot of guys out there who cycle on both materials with comparable enough wheelsets and groupsets. Maybe people who even moved their wheels and groupie from an alu to a carbon.

I find it an interesting topic anyway. There wouldn't be a range of materials available if there weren't pros and cons to each.

FISMA

Ironlungs wrote: »

I'm very interested in the perspective of cyclists who have gone from one to the other (alu to low end carbon esp.) ...
..Would a good alu frame with carbon fork and seatpost such as a Cannondale...
Would the full carbon be worth the extra €100/€200?...

I think you will do best with an Al frame and carbon fork. On a budget, I would stay away from C.

A lot of the cheaper carbon is very squishy, it loses too much energy. I have been on high end C frames for more than 20years now and have found that some of the high end steel frames transfer energy much better than C. These days, however, I think the fork is almost guaranteed to be carbon.

Given your considerations: C fork + Al frame.

Lumen

FISMA wrote: »

A lot of the cheaper carbon is very squishy, it loses too much energy. I have been on high end C frames for more than 20years now and have found that some of the high end steel frames transfer energy much better than C.

What do you mean by "transfer energy much better"?

Power is dissipated by damping, not flex. Maybe that supports your point, if the good ride quality from cheap carbon results in more damping.

These things are not simple; the bike-rider system contains some very squishy bits.

t'bear

i hope this is not considered a zombie thread at this stage, but I am short listing bikes. I am coming from a very basic Trek which has served me well to something more sophisticated. I am very close to deciding but while out climbing hills today I was prompted to reconsider. I was thinking of a carbon Rose bike with Ultegra6800 but for 100 quid less there is a alu bike with same groupset. Opinions? Use will be club spins, sportives and summer use only, keeping the Trek as a winter bike.

Lumen

tldr: forget about frame performance, just stick some latex tubes in.

http://nyvelocity.com/content/interviews/2014/josh-poertner

JP: So one of the things I've learned over the years is that we are frequently more sensitive to a persuasive argument or to confirmation bias, than we are to the small variations across similar products. In a sense, we all think we are better at 'feeling' differences than we are....

AS: To dumb it down, using the first two numbers in your chart, is it fair to say you can have a frame be twice as compliant alone in a test jig, but when you actually build it into a bike and ride it, the system will only be 1% more compliant?

JP: Essentially yes, but more like 2-3% when using real world frame stiffnesses.

AS: If the effects of frame compliance are minimal to imaginary, should we just pick frames for aerodynamics? And what’s the correlation between the much touted ‘lateral stiffness’ and efficiency?

JP: I've never seen any data or study on frame lateral stiffness affecting performance. It has often been theorized that power losses due to frame flex are very small due to the efficiency of energy return in the system, but I've never studied it specifically or seen anybody that has.

What I will say is that we've done ride studies with power/speed data including quite a bit using the Alphamantis Aerostick and when looking through the rider data, you can never see stiffness effects show in a real way. This is different than feeling a difference when you ride it, I've ridden a TVT carbon bike from the early 90's and you can feel AND even see the thing flex, but amazingly, if you are looking at speed/power data, you cannot conclusively find differences. Which doesn't mean they aren't there, it just means that they are likely buried within the margins of uncertainty of the equipment used in the testing.

...

JP: Yes, latex is probably the best bang for the buck upgrade you can ever make to any of your bikes. They are definitely more labor intensive to install than butyl, and you have to pump them up every day...but you can save 3-5 watts per wheel(!) compared to butyl.

Raam

Pump em every day... I could live with that for the good bike which doesn't get used as often but at 13e a puncture, I'm not so sure. I don't do repairs.