quality alu vs carbon frame

[alecstilleyedye]

i've been looking at bikes for around £1000 and although i have found some tempting carbon bikes with shimano 105 groupsets at that sort of price, most bikes are aluminium framed.

is a quality aluminium frame going to be any better than the 6061 T6 alu frame i have at the minute?

 

[MajorMantra]

I don't think there's any rule of thumb, it's all down to the specific design. Some will be brutally stiff making them great for sprinting, but painful over long distances. Some will be far more comfortable.

FWIW the Cannondale CAAD9 is one of the few aluminium frames on the market that still scores consistently high on all fronts and it's still popular amonst racers, especially in the US.

Matthew

 

[accountantpete]

Don't forget - the frame is only as good as the wheels.

Personally I got the stiffest frame I could find for £150 - a second hand Ridley Pegasus. Popped on a pair of stiff factory wheels and I now know what a stiff bike means - pretty crude as regards comfort but the feel you get when you tap the cranks is fantastic.

Stiffness is not only the materials used but also the design - which is why I recommend going top-end for frames.

 

[Stephen-D]

i've been looking at bikes for around £1000 and although i have found some tempting carbon bikes with shimano 105 groupsets at that sort of price, most bikes are aluminium framed.

is a quality aluminium frame going to be any better than the 6061 T6 alu frame i have at the minute?

Totally get where your coming from mate, i was in the exact same position as you, i went for an alu frame with a 105/ultegra groupset and i will be picking up my shiney new bike during the week hopefully, i went through the cycle to work scheme and got £1000, i was inititally going to spend and extra £350 on getting a Carbon frame i wanted but i found out i was going to be a dad so my finances went and dissapeared quicky, i chose a really good quality bike that im very excited about

 

[dellzeqq]

If you're middle-aged (and I'm sure that you're not) carbon forks can be a blessing. Aluminium goes 'doiinnnngggg' over bumps, while carbon just whispers 'thankyou, Master'.

 

[alecstilleyedye]

i had alu forks with the existing alu bike and will never have them again. carbon or steel are far superior in dampening road vibration.

 

[Tynan]

steel with carbon forks here, long enough to get over my initial delight but it's nice, forgotte what road buzz and vibration is

 

[GrasB]

I'd ride the bikes & do it on some harsh surface, a partially stripped tarmac surface would be perfect. Carbon v's aluminium at this price point is going to be about compromises. The carbon bikes will mostly be more forgiving but I doubt they'll have the absolute rigidity of the rear stays compared to an aluminium frame, I'd be tempted to look at ally frame with carbon forks my self.

 

[monnet]

At this price range I'd go for alu (as mentioned, Cannondale being the best bet, if a bit pricier than the competition). The reason being that cheaper carbon frames have alot of aluminium in them at the joints, and in particular in seat tube so you're not really getting a true carbon frame. Compare the weight of, say, on of the Planet X mid range carbon frames and that of a Scott CR1 or Addict - the difference is huge, and in large part due to the additional material.

 

[Stephen-D]

I think having the carbon forks should make a difference, i bought a bike with Carbo forks and Carbon seat post. maybe my ass will be more comfortable, lol

 

[MajorMantra]

At this price range I'd go for alu (as mentioned, Cannondale being the best bet, if a bit pricier than the competition). The reason being that cheaper carbon frames have alot of aluminium in them at the joints, and in particular in seat tube so you're not really getting a true carbon frame. Compare the weight of, say, on of the Planet X mid range carbon frames and that of a Scott CR1 or Addict - the difference is huge, and in large part due to the additional material.

Eh? Pretty well all carbon frames now on the market are full monocoque carbon.

Matthew

 

[fisha]

i have 2 road frames at the moment, and admittedly, one aint full carbon, but 2 mainly alu frames...

1- a few years old Trek 1400, all alu frame, with a carbon fork. medium sized butted tubing in the main triangle with thin, non particularly sculpted ( straight basically ) rear stays.

2- a 2005 Klein Quantum Q Pro. Carbon forks. frame main triangle is large butted and formed tubing, the chainstays are fat scuplted alu, and the seat stays are carbon fibre.

Having swapped kit ( bars, gears, wheels, chainset , everything ) between the pair of frames in the same day and then going for a ride, i've found:

The Klein is very very stiff. Its very direct, and put the power down, its off. You just feel the frame being really tight and having no give. The trek is much more a supple feel with its thinner tubing. Stomping on the pedals I can see, and feel to a certain extent the frame flex sideways.

Beyond that however, I've never felt that much difference once you're out and about on the road. Having the same kit on either, I wouldn't have said that one frame made me go faster than another under putting the power down, nor even that one frame felt noticably comfier than the other.... it was just that one frame felt less flexy. Both frames seemed to have the same amount of road buzz coming through the bars and seat, which on a long ride, did start to get a little weary.

The biggest thing that made a difference to that though was the tyres. I used to have 23mm tyres pumped right up hard, and you felt every little thing as you went along. I've now swapped them for 28mm tyres ( cause I use the Trek now for commuting duties ) and the difference is huge, the buzz has gone, and its a much much smoother ride all round. OK, i'm not going to win anything with big large tyres, but I was out on the bike for 6 hours yesterday, and it was just so much comfier, and not appreciably slower either.

In response to the original poster ... alu frames are very different between designs and that I personally think that unless your right into the racing, spending ££££ to get comfort via a carbon frame is not as good value as spending £ to get a different set of comfier tyres.

 

[GrasB]

At this price range I'd go for alu (as mentioned, Cannondale being the best bet, if a bit pricier than the competition). The reason being that cheaper carbon frames have alot of aluminium in them at the joints, and in particular in seat tube so you're not really getting a true carbon frame.

At this price point the weight & group set will likely be similar so it comes down to the fundamental properties of the frame & in this regard there's a difference between the two materials. While it's true that you can get close with aluminium the frame won't be as compliant but it'll almost certainly be stiffer. Different people will prefer different mixes of compliancy & stiffness.

Compare the weight of, say, on of the Planet X mid range carbon frames and that of a Scott CR1 or Addict - the difference is huge, and in large part due to the additional material.

Compare £400 frame with a frame that's £1200 or more & see that it's lighter You know what if I was to spend 3x more & it wasn't better you know what I'd be royally pi$$ed off!

 

[shippers]

I've just been comparing bikes- mainly looking at prices and weights, and it looks like you have to spend a huge amount to make any appreciable difference to your bike weight.
Giant Defy 4- £475, 11.34kg
Specialised Secteur £549, 10.1kg
Giant Defy 3- £650 (ish) 10.6kg
Specialised Allex Sport Triple- £629, 9.5kg
Specialized Secteur Sport- £649, 9.62kg

about 1.5kg for nearly a 50% increase in price!

To get serious weight reduction...

Tarmac Elite- £1600, 8.7kg
Fuji CCR-1 £2299, 8.14kg
Scott Addict LTD 2009, £8,000- 5.9kg

 

[GrasB]

From real bikes measured by a digital 'baggage scales':
'09 BeOne Road - Carbon - 7.9kg (circa £2500)
unknown year Road Fixie - 753 CrMo - 8.1kg (circa £750)
Boardman Pro Ltd - Aluminium - 9.8kg (£1000)