RIP to an old friend: The longevity of aluminium frames

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Philip Whiteman
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RIP to an old friend: The longevity of aluminium frames

Post by Philip Whiteman » 21 Nov 2011 09:29

Does anyone have any wisdom about the longevity of aluminium?

After eight years of years of heavy usage, I have decided to condemn my Giant TCR aluminium and carbon hybrid construction road bike. I have heard in some circles that aluminium frames only have a life span of around five years due to corrosion and stress fatigue. Furthermore, my frame is a carbon aluminium hybrid frame whereby the tail is constructed of aluminium and carbon bonded together. On that score, I am not too sure about the long term integrity of a bonded construction.

Saying that, the only evidence of corrosion in the frame is to be found at the bushes surrounding the bottle holder threads. Yet, I am conscious that alu bikes are life limited because of the potential stress fatigue and fractures at the welds and at points of corrosion.

The actual reason for the withdrawal is due to the sheer economics of replacing the wheel set, bars, bottom bracket and entire group set for what is obstensibly an old bike.

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George
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Post by George » 21 Nov 2011 10:08

A man who makes a habit of stamping pedals out of their cranks should probably swap his frame every season.

The rest of us can probably make an alu frame last more than 5 years. One hears scare stories about these 'modern' materials, but they often have a ring of urban myth about them, and I tend to take them with a pinch of salt. Anecdotal evidence (hearing of acquaintances whose frames snapped while out) makes me suspect that, in practice, they don't fail any more often than steel frames used to.

All the nasty 'snapping' stories I've read/heard have involved the failure of handlebar/stems, not frames.

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George
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Re: RIP to an old friend: The longevity of aluminium frames

Post by George » 21 Nov 2011 10:09

Philip Whiteman wrote:... for what is obstensibly an old bike
... but in reality a new one?

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Philip Whiteman
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Re: RIP to an old friend: The longevity of aluminium frames

Post by Philip Whiteman » 21 Nov 2011 10:16

George wrote:
Philip Whiteman wrote:... for what is obstensibly an old bike
... but in reality a new one?
Over the past year, I have had three servicable bikes but in practice only ever used two. Therefore a third has been excessive and rationalisation is probably required.
Last edited by Philip Whiteman on 21 Nov 2011 10:19, edited 1 time in total.

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AlanW
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Post by AlanW » 21 Nov 2011 10:18

Easy.....buy a Reynolds steel frame, lasts a lift time. :wink:
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Post by Philip Whiteman » 21 Nov 2011 10:25

AlanW wrote:Easy.....buy a Reynolds steel frame, lasts a lift time. :wink:
If I do purchase another bike then it will a Ti race-frame for life time longevity. Incidentally, Lisa has commissioned a Reynolds framed touring bike from Paul Hewitt. We decided that aluminium was simply not worth the investment.

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Post by GrahamGamblin » 21 Nov 2011 12:56

Aluminium does have a lower tensile strength than steel, however this is compensated for by using larger diameter tubing than steel-framed bikes to attain stiffness and strength. It is also more likely to be stressed by the welding process, so on a cheaper bike the joints may be weaker (more expensive frames can be heated and slowly cooled to strengthen the joint). Basically if you made an aluminium bike to the same design and with the same welding as steel, it wouldn't last very long, but the relative weakness of aluminium can be compensated for in the design and manufacturing processes.
Graham

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Post by Dave Cox » 21 Nov 2011 17:23

Good for Lisa - I like the Hewitt bikes pity that the shop is so far away.

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Post by spider » 21 Nov 2011 19:26

Early aluminium frames did have a bit of a habit of cracking near the welds as it is a material that is tricky to weld and the process can reduce the area close to the joint to pure aluminium, which is an excellent conductor but has a tensile strength similar to that of marzipan.
The problem was solved by complete frames being heat treated after the building process. Hence artisan frame builders, by and large, abandoned trying to build in the material.

As Alan says, a Reynolds frame will last a lifetime, but it will be prone to internal corrosion in old age. However, this usually occurs around the bottom bracket and so the resulting failure is bloody annoying rather than dangerous.

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Post by CakeStop » 21 Nov 2011 20:18

I reckon your on borrowed time already but "rationalisation" my a**e, most of us work on the n+1 principle, sounds like you use w+1 :wink:
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Post by jonnyri » 21 Nov 2011 20:25

I just bought a lovely titanium Moda from Paul at Cult Racing. Stiff enough to race but smooth as silk. Way to go Phil.

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Post by chris ankcorn » 21 Nov 2011 20:46

Dave Cox wrote:Good for Lisa - I like the Hewitt bikes pity that the shop is so far away.
Doesn't Mike Kowal supply Hewitt with his frames?

I'm pretty sure Mike Kowal is local man and trades from an agricultural type building North of Birmingham.

Does any one know more?

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AlanW
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Post by AlanW » 21 Nov 2011 23:09

There is only one UK frame builder that I would go to.
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Post by Albert Cox » 21 Nov 2011 23:21

I have just had my road/track frame, built by Bill Pollard of Coventry in 1947 ,renovated and resprayed [colour Magenta].

This is the fourth respray in it's long life.
Built of Reynolds 531, it was found to be in excellent, safe, condition when stripped to it's bare metal and carefully checked for integrity.
ALC

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Post by Rod Goodfellow » 22 Nov 2011 01:20

I have 2 1984 Vitus 979 al tubes bonded into al lugs still in regular training/racing use.No problems so far in 27 years.

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Post by spider » 22 Nov 2011 10:25

I know Mike Kowel well and, although he used to build frames, these days he is a importer of carbon frames and a range of componants. He also does a very nice respray. As Chris says his business is based in a barn between Four Oaks and Brownhills and he trades as 'Autostrada'

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Post by chalkie » 22 Nov 2011 11:52

philip give me your frame for free - i'll turn it into a single speed and flog it :!:
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alloy frames

Post by bobg » 29 Nov 2011 15:10

For those concerned about the life of alloy frames, i believe that fatigue failures will always start with a hairline crack, which could be there for a considerable time before a fracture occurs. The point of this being that it is possible to buy a inexpensive crack detection kit. (about £25 ) that would do maybe 20 or so inspections. The one that i found on the web was from a aerospace company and is recomended for use on aicraft landing gear etc. It comes in 3 aerosol cans, a cleaner, a penetrating dye and a flaw finder. Very easy to use, first the cleaner, then the dye that will penetrate into the most minute of cracks, wipe the dye off and apply the flaw finder and any dye left in cracks will show up.

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Post by Philip Whiteman » 29 Nov 2011 15:33

1. Thanks Bob, that is really interesting. Where can these be obtained from?

2. The frame has been donated to Charles for renovation.

3. I vividly recall a very nasty accident on a club run caused by a fracture in a L shaped steel stem. Upon close inspection, I noted that only 2mm was fresh as the remainder of the break was rusty. The bicycle had been subject to an earlier collision and had been stored in the open air.

The accident occured near to Bredon Hill. The cyclist concerned was an American who was visiting another Beacon member. During the ride, the stem snapped clean into two, the rider lost total control and he landed head first onto a tarmac pavement with a sickening thud. He lost consciousness and went into convulsions. He was treated at A&E where he was diagnosed with minor but reversible brain injuries. The club run was instantly terminated and the 20 strong group returned to Birmingham in a state of shock.

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Crack detection

Post by bobg » 29 Nov 2011 16:34

Hi Philip, The failure that you described Is absolutely typical, as the crack had obviously been there for some time. When i was a lad and a steam train pulled into the station someone would walk along tapping the wheels with a hammer.If it rang like a bell it was ok, if the sound was more of a thud it denoted a cracked wheel and needed changing. But doubt if that would work on a frame. However the company that has the kits is. LAS Aerospace. www.lasaero.com

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Philip Whiteman
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Re: Crack detection

Post by Philip Whiteman » 29 Nov 2011 17:09

bobg wrote:. When i was a lad and a steam train pulled into the station someone would walk along tapping the wheels with a hammer.
I am probably the only member of the Beacon who can proclaim to have undertaken that job. In my role as Carriage and Wagon Chief Examiner for the K&ESR during the early 90s, I used to tap wheels. Ultrasonic test kits were available at the time but were prohibitively expensive for a heritage railway. The tap hammer was effectively a small ball hammer with a very long handle. Fortunately, I never heard a thud. The major disadvantage was the inability to test tyres whilst the vehicle was located on a curve, not something that would have been a problem for ultrasonics. The only reason I had to withdraw wheels for re-tyring or lathing was usually due to the infamous flat.

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Re: Crack detection

Post by CakeStop » 29 Nov 2011 19:45

Philip Whiteman wrote:The only reason I had to withdraw wheels for re-tyring or lathing was usually due to the infamous flat.
Blimey, if trains can't withstand the hedge cuttings there's no hope for us cyclists :shock:
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Post by slogfester » 03 Dec 2011 12:41

My last alu framed bike cracked after 4.5 years at the lug join of the chain and seat stays. A friend of mine in Oz who is 55 kg in wet cloths had 2 maybe 3 Cannodale Six alu frames break on him.

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Post by ForeverProvence » 03 Dec 2011 21:16

My Cannondale CAAD3's still going strong after 5 1/2 years of exclusive use. Pity it rides like a garden gate.
Eddy Merckx, when asked for his advice to younger riders who wanted to become professionals: ''Ride lots.''

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