Insanely expensive bikes

[bagpuss]

The late Ray Booty once told me with regard the cost of a bike. " Its no good having a £1.000 bike if you have only got a £100 pair of legs"

 

[alex_cycles]

The late Ray Booty once told me with regard the cost of a bike. " Its no good having a £1.000 bike if you have only got a £100 pair of legs"

They don't make bikes cheap enough to be a good match for most of our legs then

 

[Alex321]

While Hambini is a competent engineer many of his videos are done for shock value admittedly but you can see the issues he is raising. Raoul at Luscher Technik is completely different, he is a huge fan of CF and has even made his own CF frames. He is an ex-Boeing CF engineer and he is very plain speaking with no obvious bias I can find and I pretty much trust completely what he states. When he is literally showing you the voids and issues in these frames how on earth can you doubt it? From what I've seen elsewhere such manufacturing issues reduce the stated load capacity of such frames so if you have a CF frame stated for riders up to 120kg but with serious manufacturing issues the real weight rating for that frame could be maybe 60-90kg because of the structural imperfections. That's just a random figure I have come up with but you get my point that structurally they are much weaker but still sufficient strength perhaps for the majority of cyclists who ride them. A compromised frame structurally doesn't mean immediate failure but obviously there is a huge safety implication especially for heavier riders.

The fact is you can have two identical CF bikes but one is significantly weaker than the other despite both being used to the same level. You can get that with aluminium and to a lesser extent steel if one frame has been used far more than the other with heavily fatigued tubes but not straight out of the showroom typically.

All this is theoretical reduction in strength.

Has he actually then tested samples of the frames with and without these voids or other issues to destruction, to find out what their actual strengths are?

Perhaps the stated 120kg weight limit is correct for the frames with issues, and the perfect ones could take 150Kg.

I would hope that the manufacturers build in reasonable margins in their stated weight limits, and would also hope they test those using standard frames, not ones which have been specially prepared. They don't want to be getting hundreds of claims for damages due to failed frames.

 

[alex_cycles]

All this is theoretical reduction in strength.

Has he actually then tested samples of the frames with and without these voids or other issues to destruction, to find out what their actual strengths are?

Perhaps the stated 120kg weight limit is correct for the frames with issues, and the perfect ones could take 150Kg.

I would hope that the manufacturers build in reasonable margins in their stated weight limits, and would also hope they test those using standard frames, not ones which have been specially prepared. They don't want to be getting hundreds of claims for damages due to failed frames.

Indeed. It's not like we hear stories of hundreds of failed frames.

 

[bonzobanana]

All this is theoretical reduction in strength.

Has he actually then tested samples of the frames with and without these voids or other issues to destruction, to find out what their actual strengths are?

Perhaps the stated 120kg weight limit is correct for the frames with issues, and the perfect ones could take 150Kg.

I would hope that the manufacturers build in reasonable margins in their stated weight limits, and would also hope they test those using standard frames, not ones which have been specially prepared. They don't want to be getting hundreds of claims for damages due to failed frames.

I don't think its theoretical at all as Raoul is highly skilled and his business is based on checking and repairing CF frames and has shown many frames and forks that have failed due to poor manufacturing as well as frames and forks that have just failed due to impacts and over-tightening etc.

It's important to understand CF frames are hand-made and therefore can vary in quality quite a lot. The process of QC checking presumably can fail on occasion especially with large orders. While CF is a state of the art material the manufacturing process is labour intensive and quite basic.

If you look at this picture from the Quest Composite site that makes Canyon and Trek frames you can see terrible conditions, sitting on small tables, hair nets not being worn properly and just horrible vile working conditions for CF production. Only one of those people has to lay up the CF badly to create an issue in some frames or forks etc. CF production is recognised as the least consistent of all frame materials with the worst working conditions because of the long hours needed for frame and fork production.

 

[Alex321]

I don't think its theoretical at all

So where is the data on him testing them to destruction?

Without that, it most certainly is theoretical.

But you didn't address what I said in the rest of that post at all. Those defects may well make the frames weaker. But "weaker" is a relative term. It may be (and IMO is very likely) that the "weaker" frames are in fact perfectly suitable for the average rider who weighs as much as the manufacturer stated limit.

You keep talking as if his data shows these frames to be not fit for purpose, when if that were the case, manufacturers would be facing unacceptable numbers of claims, and we would be hearing horror stories all the time about frames failing in normal use.

 

[bonzobanana]

So where is the data on him testing them to destruction?

Without that, it most certainly is theoretical.

But you didn't address what I said in the rest of that post at all. Those defects may well make the frames weaker. But "weaker" is a relative term. It may be (and IMO is very likely) that the "weaker" frames are in fact perfectly suitable for the average rider who weighs as much as the manufacturer stated limit.

You keep talking as if his data shows these frames to be not fit for purpose, when if that were the case, manufacturers would be facing unacceptable numbers of claims, and we would be hearing horror stories all the time about frames failing in normal use.

Its an interesting theory that the manufacturer's weight limits allow for poor construction and these frames and forks are still capable of their stated weight limits. I personally think its far more likely the weight limits are reduced but still capable of handling most cyclists. Despite CF bikes making up a tiny percentage of bikes sales the number of recalls for CF frames and forks is very high compared to other materials. However lack of exact data doesn't stop anyone from using their common sense that voids and cracks in CF will reduce safety and weight capacity of those components. You don't need data to understand a ship with a hole in the side of its bow will sink or a huge crack in the middle of a bridge will cause it to fail etc. You can make logical assumptions rather than illogical assumptions.

When frames and forks are designed and engineered it will be to a specification and when manufactured many samples will be used to test to the certification standards and required tests. The manufacturer or independent test house will not be using poorly manufactured frames for certification purposes. Many of the frames that failed that Raoul has dealt with has been due to manufacturing errors but others he has analysed due to accidents etc. He has plenty of videos on his Youtube channel of varying types.

The idea that its just theory that a poorly manufactured frame is more likely to fail is to be honest delusional. Cracks and voids are easy to understand that they reduce the strength of that material. Maybe one day someone will pay to have a poorly made CF frame and fork go through the certification process testing to see how it compares with a well made frame but I can't see where the money would come from to do those tests which could cost 10s of thousands of pounds. Certification testing isn't cheap.

 

[fossyant]

I think bonzo doesn't like carbon bikes

 

[alex_cycles]

I think bonzo doesn't like carbon bikes

I think it's getting boring now

 

[fossyant]

You can get badly welded bikes made in sweat shops in the far east - made of steel and alluminium. Many are poorly made generally.

 

[Alex321]

The idea that its just theory that a poorly manufactured frame is more likely to fail is to be honest delusional.

1. You need to learn what the word "theory" means. You can be 99.999999% certain of what will happen, but until physically tested, it is "just" theory.
2. This is pretty well irrelevant anyhow, since nobody has suggested for one moment that they wouldn't be more likely to fail. It stands to reason they would, so that is a complete straw man.

Cracks and voids are easy to understand that they reduce the strength of that material. Maybe one day someone will pay to have a poorly made CF frame and fork go through the certification process testing to see how it compares with a well made frame but I can't see where the money would come from to do those tests which could cost 10s of thousands of pounds. Certification testing isn't cheap.

I would be very surprised if manufacturers carefully select which frames get tested to use only the best ones. That would work out FAR more expensive in the long term.

I would be even more surprised if their stated weight limits don't have a BIG margin built in, to the extent that any frame that gets through their regular QA process will be strong enough to handle that limit.

Manufacturers aren't stupid, and they know that a lot of their sales hinge on their reputation. The reputable manufacturers simply aren't going to allow frames out of such poor quality that any significant number will fail in normal use, when ridden by normal riders within the stated weight limits.

 

[SkipdiverJohn]

You can get badly welded bikes made in sweat shops in the far east - made of steel and alluminium. Many are poorly made generally.

That's true, but welded steel frames can generally be mass produced with a high degree of repeatability and really poor welding is usually visible, and quite obvious to anyone who knows what good welding looks like.
With carbon fibre frames on the other hand, the defects are hidden within the inner structure, and at the minimum, you would need an endoscope type camera to inspect one non-destructively.

 

[Deleted User]

I suppose the answer is, if you don't think Carbon is safe, not for you or just plain shyte, stick to something else.

 

[Kestevan]

I suppose the answer is, if you don't think Carbon is safe, not for you or just plain shyte, stick to something else.

But, but, but I really need to tell everyone who doesn't agree with me that they're wrong...

Or at least I would need to if I hadn't already been killed multiple times by faulty carbon frames.

 

[bonzobanana]

I think bonzo doesn't like carbon bikes

That's just a childish response for sure especially as I really like CF bikes I believe they are a wonderful creation but like any performance product its a compromise. No one is going to say Ferrari or McLaren cars are reliable or safer than standard cars its just the nature of their design, performance as a priority in design. Anyway it always feels when you get an insulting reply in a normal discussion the person receiving the insult has won the argument so thanks for that.