Carbon v aluminum framed bikes

Welshkev

Was just wondering what's the fundamental difference between a carbon and aluminium bike?

I'd always thought it was mainly the weight, but say there was an aluminium bike at 6.7kg and a carbon at 7.5kg - what's the benefit of the carbon?

Cheers

MajesticDonkey

Carbon is stiffer and far more responsive in my opinion. It's generally lighter. A top of the line aluminium frame would probably be as light as a medium range carbon frame.

colm_gti

Kevinleeowen wrote: »

Was just wondering what's the fundamental difference between a carbon and aluminium bike?

Fundamental difference....one is made of carbon, the other is made of aluminium (or aluminum, depending on what part of the world you're in).

Happy Friday

Seweryn

colm_gti wrote: »

Fundamental difference....one is made of carbon, the other is made of aluminium (or aluminum, depending on what part of the world you're in).

Happy Friday

And that's about it! There are so many bikes and designs that there is no like for like comparison.

nordicb

As mentioned, stiffness. Carbon frame helps to transfer all you have to the wheels. It's noticeable in the crankset area especially, when you go up the hill pushing pedals hard, aluminum frame swings right and left, while carbon frame doesn't do that, or not to that extent.

Lumen

nordicb wrote: »

As mentioned, stiffness. Carbon frame helps to transfer all you have to the wheels. It's noticeable in the crankset area especially, when you go up the hill pushing pedals hard, aluminum frame swings right and left, while carbon frame doesn't do that, or not to that extent.

Depends on the frames. There are some carbon frames that have significantly less BB stiffness than some aluminium frames.

So it's a very bad idea to base a purchasing decision based purely on the frame material.

Wouldn't be an issue if people rode bikes before they bought them, but in an age of internet purchases and snotty shops that's often not possible.

dave2pvd

nordicb wrote: »

As mentioned, stiffness. Carbon frame helps to transfer all you have to the wheels. It's noticeable in the crankset area especially, when you go up the hill pushing pedals hard, aluminum frame swings right and left, while carbon frame doesn't do that, or not to that extent.

Carbon is no magic pill. You can't generalize about characteristics of either. Remember, you can make sails with carbon fiber. It's not always stiff. And certainly, there are a lot of cheap CF frames out there that are heavy and flex quite a bit. Conversely, there are some seriously stiff aluminum frames used in all disciplines of cycling.

What colm_gti said is the correct answer.

Seweryn

nordicb wrote: »

Carbon frame helps to transfer all you have to the wheels. It's noticeable in the crankset area especially, when you go up the hill pushing pedals hard, aluminum frame swings right and left, while carbon frame doesn't do that, or not to that extent.

Which aluminium frame vs which CF fame?

Bit of a nonsense there, if you ask me... (the aluminium frame in my bike doesn't do anything you are saying).

TychoCaine

Because of the way carbon frames are built they can be made very flexible in one direction while staying very stiff in the other. They'll soak up the bumps and still not flex when you get out of the saddle. You can do something similar with aluminium by curving the stays and using exoticly shaped tubing, but not to the same extent.

Welshkev

Thanks - I was just browsing (hoping to purchase THE bike next year) and saw the spec on a Rose bike - components looked pretty top notch (in my humble opinion) - such as Di2 groupset, but noticed the frame was aluminium. Bike was around €2,500, so I was surpised the frame was aluminium.
Having never ridden a carbon, and the general 'vibe' being carbon is superior, I was surprised to see an aluminium bike at this price, but it looks every bit better than some carbon framed bikes I see at significantly less money - so was curious

Cork24

Kevinleeowen wrote: »

Was just wondering what's the fundamental difference between a carbon and aluminium bike?

I'd always thought it was mainly the weight, but say there was an aluminium bike at 6.7kg and a carbon at 7.5kg - what's the benefit of the carbon?

Cheers

I have a HPA Cube bike 2012 Edition comes in at 7.2 Kg, Want a Lighter Bike .. ? Lose Weight I seen heavy people on Carbon Bikes thinking they will go Faster,
forgetting the 90 + kg has nothing got to do with speed..

laraghrider

If a bike is €2,500 and has a Di2 groupset then all the money your paying for is largely going on the groupset. You can see some manufactures will sell (different models) carbon framed bikes at the same price but one may have say a 105 set and the other an ultegra. For that you look at where the money was saved elsewhere on the ultegra bike and likely it could be wheels and frame.

Personally i'd not spend €2,500 on an alu frame with Di2. Reason being for the level of riding I do I think Di2 is a waste of money for me personally. I'd rather save money on the groupset and get a better frame or wheel set. A lot of pro's don't even use it and almost all continental teams don't use it due to the cost.

TinyExplosions

Aluminum bike with Ultegra Di2 for under 2k

There's nothing wrong with expensive Alu bikes -hell one of the top regarded Cannondale frames is alloy!

I guess part of it is snobbery, you have 2.5k to spend, would you rather have a top end groupset or a top end frame material (in peoples opinion, not my own!) or would you rather save money and go for something else.

laraghrider

TinyExplosions wrote: »

I guess part of it is snobbery, you have 2.5k to spend, would you rather have a top end groupset or a top end frame material (in peoples opinion, not my own!) or would you rather save money and go for something else.

How is that snobbery? Is it not simply a choice that all people make? You have a budget and you decide where to spend the money and where to save it.

TinyExplosions

laraghrider wrote: »

How is that snobbery? Is it not simply a choice that all people make? You have a budget and you decide where to spend the money and where to save it.

Because no one *needs* a top of the line group set, or a fancy carbon (or steel) frame -a basic, few hundred quid job will do ye, but we like to able to say that we're running dura ace or Super Record (or SRAM Red) etc etc -very good marketing that we all fall for "they'll laugh at me on the club spin if I turn up with anything less than 105"

Maybe snobbery ain't the right word, but still (and I'm as guilty of it as everyone else!)

MungoMan

I know top pro teams ride what they are told to ride, but would you find anyone in the peleton with an Aluminium alloy frame ?

Vino Veritas

More often than you think , usually when sponsor has a top Alu alternative available as a choice, also two English Pro teams on Steel . Carbon is the number one choice now , but it was not always that way , and will change again

Brian?

Vino Veritas wrote: »

More often than you think , usually when sponsor has a top Alu alternative available as a choice, also two English Pro teams on Steel . Carbon is the number one choice now , but it was not always that way , and will change again

It may change from Carbon to some other material. It won't go back to steel, aluminium or titanium though.

recedite

Cork24 wrote: »

Lose Weight I seen heavy people on Carbon Bikes thinking they will go Faster,
forgetting the 90 + kg has nothing got to do with speed..

+1
Losing 1 kg of fat will probably do more for you than losing 2kg off the bike frame. Because fat cells tap into your bloodstream for their oxygen supply, but bike components don't.

MungoMan

Vino Veritas wrote: »

More often than you think , usually when sponsor has a top Alu alternative available as a choice, also two English Pro teams on Steel . Carbon is the number one choice now , but it was not always that way , and will change again

who are the english pro teams on steel ?

is it possible to have a 6.8 kilo steel bike with normal components

Vino Veritas

No - they are heavier according to below - but made to measure , and winning races .

http://roadcyclinguk.com/gear/pro-bike-dean-downings-genesis-volare-953.html

endacl

This may be under the heading of 'almost never happens', but aluminium won't shatter in a crash...

TychoCaine

Vino Veritas wrote: »

No - they are heavier according to below - but made to measure , and winning races .

http://roadcyclinguk.com/gear/pro-bike-dean-downings-genesis-volare-953.html

Heavy is an understatement. Going by the above article a professional grade steel frame is still 50% heavier than a cheap (i.e. my) carbon frame.

colm_gti

TychoCaine wrote: »

Heavy is an understatement. Going by the above article a professional grade steel frame is still 50% heavier than a cheap (i.e. my) carbon frame.

But it's probably way stiffer, and they can't be lighter than 6.8kgs anyway...

Seweryn

TychoCaine wrote: »

Heavy is an understatement. Going by the above article a professional grade steel frame is still 50% heavier than a cheap (i.e. my) carbon frame.

That is still only about 0.5 kg. You sweat out more on a short afternoon spin on your bike.

endacl

Seweryn wrote: »

That is still only about 0.5 kg. You sweat out more on a short afternoon spin on your bike.

You pump out more than half a kilo of sweat on a short spin?!?

See a doctor!

TychoCaine

colm_gti wrote: »

But it's probably way stiffer, and they can't be lighter than 6.8kgs anyway...

There's no way you'll get a steel bike anywhere the UCI weight limit. Not without everything else being made from carbon and titanium anyway. The race that pro won on a steel bike was a criterium, just like most of the UK pro calendar. You spend more time on the ground than in the saddle in crits, and steel will stand up to regular crashes better, which is probably why he was using it.

Vino Veritas

No, they use them for all events. There was even one in our Elite nationals this year. I thimk that if you are of a suitable weight for Cycling, BikeFit, Reliability, Performance are more important than Frame weight.

colm_gti

Vino Veritas wrote: »

No - they are heavier according to below - but made to measure , and winning races .

http://roadcyclinguk.com/gear/pro-bike-dean-downings-genesis-volare-953.html

Lovely looking bike...

Ole Rodrigo

Looks like the Ritte Bosberg, also very nice.