Question about aluminium frame challenge to carbon fibre frames?

[Rain drops]

Aluminium frames appear to be resurgent in challenge to carbon fibre frames, in both light weight, and compliance. Is this sensible with regard to durability, and longevity? Aluminium has problems in situations where it is subject to continual flexing, which leads to fatigue failure. (Sudden snapping.) Those of us into sea sports (windsurfing in particular) were continually having to replace alloy booms (built to unavoidably flex somewhat) on nearly a yearly basis, and blessed the day composites (carbon fibre) took their place. Carbon fibre, provided it does not exceed its design limits of flexing, is almost impervious to fatigue.

It will be interesting to see if these lightweight alloy bikes with higher compliance (comfort) now challenging the role of carbon fibre (why, for goodness sake?) are indeed long lasting and durable? I would assume not! I used a Boardman Comp (£600) road bike originally but laid it up after 5 years use for fear of fatigue failure around the welds of the bottom bracket area. The current pair of carbon fibre bikes should be impervious to fatigue, apart crash failure, and should see me out.

M.T.B.'s successfully use alloy frames but they are not subject to smoothing compliance in that the full suspension plays that role, and the frames can be kept rigid. I see no downside in their design.

 

[Cycleops]

Carbon is what the pros use innit?

 

[Sittingduck]

Prices have gone up a lot in recent years. People will only fork out so much and therefore sales of alu based bikes are up. That’s my theory anyway. I don't think it’s increased desirability of alu, just what folks are prepared to pay.

 

[Sharky]

I've been riding alloy frames since 2005, without problems. Previously rode steel, whilst good to ride, eventually succomed to rust. Haven't tried carbon, as they always seem above my price point.

Do have any links to the new breed of alloy bikes?

 

[kingrollo]

Aluminium frames appear to be resurgent in challenge to carbon fibre frames, in both light weight, and compliance. Is this sensible with regard to durability, and longevity? Aluminium has problems in situations where it is subject to continual flexing, which leads to fatigue failure. (Sudden snapping.) Those of us into sea sports (windsurfing in particular) were continually having to replace alloy booms (built to unavoidably flex somewhat) on nearly a yearly basis, and blessed the day composites (carbon fibre) took their place. Carbon fibre, provided it does not exceed its design limits of flexing, is almost impervious to fatigue.

It will be interesting to see if these lightweight alloy bikes with higher compliance (comfort) now challenging the role of carbon fibre (why, for goodness sake?) are indeed long lasting and durable? I would assume not! I used a Boardman Comp (£600) road bike originally but laid it up after 5 years use for fear of fatigue failure around the welds of the bottom bracket area. The current pair of carbon fibre bikes should be impervious to fatigue, apart crash failure, and should see me out.

M.T.B.'s successfully use alloy frames but they are not subject to smoothing compliance in that the full suspension plays that role, and the frames can be kept rigid. I see no downside in their design.

Where have you learnt there has been a resurgence in alu ?

Magazine article ? Bloke who owns a bike shop ?

 

[Red17]

Most motorcycles use alloy frames with no snapping issues.

 

[cougie uk]

Aluminium frames appear to be resurgent in challenge to carbon fibre frames, in both light weight, and compliance. Is this sensible with regard to durability, and longevity? Aluminium has problems in situations where it is subject to continual flexing, which leads to fatigue failure. (Sudden snapping.) Those of us into sea sports (windsurfing in particular) were continually having to replace alloy booms (built to unavoidably flex somewhat) on nearly a yearly basis, and blessed the day composites (carbon fibre) took their place. Carbon fibre, provided it does not exceed its design limits of flexing, is almost impervious to fatigue.

It will be interesting to see if these lightweight alloy bikes with higher compliance (comfort) now challenging the role of carbon fibre (why, for goodness sake?) are indeed long lasting and durable? I would assume not! I used a Boardman Comp (£600) road bike originally but laid it up after 5 years use for fear of fatigue failure around the welds of the bottom bracket area. The current pair of carbon fibre bikes should be impervious to fatigue, apart crash failure, and should see me out.

M.T.B.'s successfully use alloy frames but they are not subject to smoothing compliance in that the full suspension plays that role, and the frames can be kept rigid. I see no downside in their design.

I've an alu bike that's had much more than 5 years wear on it and is absolutely fine. I think you're being a bit cautious.

 

[cyberknight]

I have a 2011 boardman comp still going strong , still rides nicely

 

[Ming the Merciless]

This is only a question a serious cyclist would care about.

 

[ColinJ]

I am still whizzing about on...

<------ that one

20 years and counting. At times I have weighed over 115 kg (18 stone), hit speeds of 90+ kph (55+ mph), and ridden some very rough roads. It hasn't fallen apart yet!

 

[Ian H]

Things that make a bike more (or less) comfortable: wheelbase, frame angles, saddle, size of tyres.

 

[Cycleops]

My 2007 Trek rescued from under a pile of abandoned bikes here still going strong:

 

[Rain drops]

Cycling Plus magazine appear to be favouring the 'latest breed' of aluminium bikes in their tests as worthy rivals to carbon fibre bikes. (I suppose they need some gimmick to stoke interest.)

For an alloy frame to match a carbon fibre frame weight for weight it would have to be thinner tubed and weaker. To match it strength wise it would have to be thicker tubed and heavier. (There are other advantages of carbon fibre but that is not the point.)

Aluminium alloys have a definite fatigue half life when subject to flexing. The more the flex, the shorter the half life, after which the alloy is claimed to case harden and become more brittle, which eventually leads to failure. Obviously, if the alloy is used in a rigid non flexing manner (Motor cycles and Mountain bikes both of which use suspension to absorb shock loading) its half life will be considerably extended, but the latest aluminium bikes are lighter and boast more compliance (flexing) which is the opposite to rigidity.

The other obvious shortcoming of aluminium alloy is corrosion from heavily salted winter roads, especially where the alloy is mixes with stainless steel fittings which causes galvanic corrosion. We all choose what risks to take, and extensive use of alloy and its failings in salt water has turned me against its use, long term, on salty winter roads, as my older alloy Boardman Comp bike was heavily used. I was almost waiting for that sudden bang, as something snapped!

Good luck to those who find it doesn't break, but that luck. perhaps, may not last. (My Boardman Comp bike was not particularly flexible , and was fairly harsh riding, but it was surprisingly fast.)

 

[Smokin Joe]

I've an alu bike that's had much more than 5 years wear on it and is absolutely fine. I think you're being a bit cautious.

I had a Scandium alu frame (As thin walled as it gets) for seven years and it was still in A1 condition when I sold it to a guy who subsequently went on to race it.

People who question the safety of aluminium for frames are happy to ride about with alloy bars and stem, cranks, seatposts, rims and hubs etc without worrying about a catastrophic failure.

 

[HLaB]

I had a Scandium alu frame (As thin walled as it gets) for seven years and it was still in A1 condition when I sold it to a guy who subsequently went on to race it.

People who question the safety of aluminium for frames are happy to ride about with alloy bars and stem, cranks, seatposts, rims and hubs etc without worrying about a catastrophic failure.

That (a scandium frame), touchwood, is the only material I have had fail on me.