Julian Edgar, 50, has been writing about car modification and automotive technology for nearly 25 years. He has owned cars with two, three, four, five, six and eight cylinders; single turbo, twin turbo, supercharged, diesel and hybrid electric drivelines. He lists his transport interests as turbocharging, aerodynamics, suspension design and human-powered vehicles.
Thank you all
Thank you.
Thanks to all of you; but to especially those who have been reading my material for a long time.
By your praise, and by your criticism, and by your demands that I produce the best for you that I can, you have all made me a far better self-taught engineer than I would ever otherwise have become.
Because I know that if I say something like: “This performance mod makes the car go faster” there will be a chorus of “Prove it!”, or “How much faster?”
I know if I write something about (say) how an anti-roll bar works, and I get it wrong, there will immediately be people happy and ready to correct me.
Doing this job for nearly ten years has taught me, in a way that I’d not realised before today, that in mechanical things I constantly internally justify what I do and how I am doing it, and that in everything I do I need to cite evidence that it works.
So thank you all.
And can I also say, you’re equally all responsible for my being today thrown off a discussion group!
Ah, the swings and roundabouts…
Many of you will know that about two years ago I became fascinated by Human Powered Vehicles. I bought a commercially produced recumbent pedal trike and then, after a time, thought I could do better and so built my own. Primary in its advantages was its use of full suspension, but it proved to be a very heavy machine – and so I started again.
That machine finished, I thought I could again do better, so started for a third time. And the latest machine, pictured at the top of this screen, was finished just a few days ago.
During this process, and especially during the design and construction of this last machine, I’ve been reading and contributing to an on-line discussion group related to recumbent bikes and trikes. In this extreme minority pursuit, it makes sense to see what others have done.
However, displaying the arrogance that the owner of the discussion group cited when suggesting I shut up, I soon found that my knowledge of suspension design was apparently far greater than anyone contributing – and that those labouring under misapprehensions actively didn’t want to improve their understanding. Why? Well, you see, their machines were already so good!
And here’s where it’s all your fault.
It seemed (and seems) to me that in a pursuit where it’s impossible for many people to experience the machines for themselves (there are too few recumbent trikes scattered too widely), the best way of making any assessments of the worth of designs is to do some testing.
Like, I know that if I say to you: “My trike corners really well – brilliantly in fact”, you’ll say to me: “Well, prove it!”
So without even much thinking about it, I did some flat, dry-road skidpan testing of the trikes I built – and compared those lateral acceleration figures to the commercial trikes I have access to. The results were very close (gee, the skidpan is a tough test!) but my trikes were a fraction better than the others.
Now genuinely thinking that everyone else building trikes would dearly love to see how their machines fared, I posted the test procedure and results on the discussion group. I honestly expected a flood of test results – many of which I thought would be better than I’d achieved. That way I could look at those designs, assess why they were better, and so learn from others.
But nope, not one person who said how great their machine handled was prepared to test it. Not one solitary person!
Well, if you’ll excuse the language, fuck me.
Then we got on the topic of ride comfort. As always, people told me that no suspension was required – their trikes rode just wonderfully. And if they did need suspension, well, only an inch was required. So, in response, I wrote a 5-part series on human powered vehicle suspension design, showing that to achieve good human ride comfort, a low natural frequency suspension is needed. And to achieve that, a high static deflection and long travel are required.
The physics is all in the textbooks – I didn’t make it up.
But I don’t think I got even one comment that showed anyone had read the series. Well, that’s fine, but it makes it a bit hard to have any meaningful discussion about what is needed in suspension design, doesn’t it?
So, nothing deterred (I must have been mad: they were never going to see any light) I data-logged the vertical accelerations experienced at the seat of my trikes and others. That way, you could simply look at a line on a graph and see for yourself the actual, measured ride comfort!
No-one seemed to take the implications on board.
The last straw was a bloke who put up pics of his suspension trike. It was a design that had absolutely clear and major shortcomings, and – oddly enough – his photos of his previous versions showed much better designs that he had then not optimised. Everyone else told him how wonderful his machine was; I asked questions about its deficiencies and suggested reasons for them. That went down like a lead balloon.
So despite plenty saying how wonderfully their trikes handled, no one wanted to make any measured comparisons.
Despite people talking about their trike’s superior ride comfort, no-one wanted to compare ride comfort (even via a video over measured bumps on the road!).
No-one wanted to analyse design advantages and disadvantages of alternative suspension approaches.
No-one wanted to discuss the theories behind suspension design and ride comfort.
In fact, there was no justification of statements being made, some theories being expounded were completely wrong, people seemed more interested in praising each other rather than improving results, and researching theory was regarded as being unnecessary.
I don’t think I could get away with that in AutoSpeed very long.
So again, thank you.
on November 26th, 2007 at 12:57 pm
Hey Julian,
How dare you come into their dogma and suggest actual evidence to support claims! Years ago you would have seen the kindling appear and the stake being driven into the ground whilst the horde began circling around you 😉
Remember:
You can lead someone to knowledge but you cannot make them think……
Have a beer on me,
cheers
toddly
on November 26th, 2007 at 3:31 pm
Y’know I have often criticised car discussion groups but at least in most of those:
– people call lousy designs for what they are – they don’t just give everyone warm hugs irrespective of the rubbish produced
– people criticise commercial products and talk about how to improve them, not pretend that all is perfect until the next model comes out
– people use measurements of performance
– (sometimes) people realise that proper theory underpins design
Until now I hadn’t realised how useful all those things are!
on November 26th, 2007 at 4:28 pm
Hi Julian
the ability to accept both types of criticism – both constructive and of the other kind – and not get upset – is the mark of a man.
I’ve worked with qualified engineers who don’t even know which end of a wrench is which, so I applaud the thinking person who doesn’t just look at something to see how it works, but who also thinks three steps ahead on how it can be further improved.
A practical engineer is one who does not only look at what he has, he understands the processes, like welding, etc involved, and lists his available resources. You also need a passion for it, a trait sadly missing in many of today’s graduates.
Just because you get dropped from a self-centered discussion group because you didn’t fit into their idea of the ideal profile is their loss.
Call a spade a spade, as is your style.
Cheers
Vincent
on November 26th, 2007 at 5:02 pm
I’ve long believed that the measure of a good information source isn’t what they praise, but what they criticize, and how.
Likewise, I was stunned to find that car news groups were actually way AHEAD of the mean when it comes to logical discussion of issues.
Likewise car magazines. Even the most picture dominated modified street racing magazine will put in the odd 1/4 mile time or dyno result. Now compare that to say… a fashion magazine talking about cosmetics, or house and garden, or excercise and fitness mags. When do they ever give a measure of how well the beautifully photographed product ever works. Any kind of comparable number at all?
on November 26th, 2007 at 6:34 pm
Julian, I always appreciate the fact that you call a spade a spade, when there are too many journalists in the industry who will say what they think the manufacturer wants them to say….
Similarly, people often are not prepared to accept negative comments, or are not interested in real test results….as you’ve described in this blog post.
Keep up the good work!
on November 27th, 2007 at 7:22 am
Have you a writeup anywhere on the web about the pictured trike?
on November 27th, 2007 at 7:28 am
No not yet. We’ll be covering it in two parts in AutoSpeed.
The first part is written and will appear as our last article for the year on December 17. This story is on the detail of the design, with lots of close-up pics.
The second part, on testing and results, will appear early next year.
on November 27th, 2007 at 8:11 am
I’m pretty sure that the IEA states as one of the core values required of it’s chartered engineers is to pass information and experience onto younger/less experienced engineers otherwise that useful knowledge is lost.
An earlier post mentions that an engineer needs to have a passion about what they are doing which is very true but there are some engineers who don’t think outside the square and ‘9 to 5’ the day away, but their process oriented skills are still very valuable in the right application.
These days most advertising by educational institutions regarding the engineering profession seems to focus on how much you can earn rather than focusing on the satisfaction the job gives you.
The majority of the graduates here where I work are passionate and very smart they just need someone experienced to pass on their knowledge. However these grads should also be willing to listen to (constructive) criticism as engineering is all about Failure Mode Analysis, a good engineer will always put their design up for scrutiny if for nothing else than to talk about different methods that they have seen problems solved.
on November 27th, 2007 at 12:53 pm
Fancy that? A web discussion forum full of uneducated dickheads?? Who would have thought it?
on December 4th, 2007 at 3:34 pm
Interestingly enough I was in a car club once and supplied alot of in depth technical articles for their magazine at no cost to them. The articles I wrote were not appreciated by the individuals in the club. I was also involved with judging at a number of concourses for the club and because the vehicles I judged to be the winners primarily because of the techinal achievements and not how “pretty” they looked I was ostracied. So I left them.
I figure if people are not mentallly capable of taking constructive input or criticism you’re better off without ’em.
Keep up the excellent informative articles.
on December 4th, 2007 at 8:21 pm
My Marine drill instructor once said a grain of observation outweighs a pound of speculation any day. Yet often we run into those who choose illusions over the facts and data. I don’t understand it either. But sometimes, our confidence in knowing the facts and data comes over as arrogance even though that is the furthest thing from our minds.
I suspect the trike forum will soon enough notice a malaise, a certain amount of ennui descends. Call it a ‘vacation’ and wait six months. By then, you’ll have moved to more advanced studies and can contact the group to see if they have any interest in your work. If not, you’ll have another article for here.
Bob Wilson
on December 15th, 2007 at 7:15 am
Sorry, slightly off topic but…
Have you ever looked into human CO2 emissions vs. power produced?
Are you concearned that if more human powered vehicles hit the roads then human CO2 emmissions will be given reduction targets?
We migh have to switch from Oxygen to Hydrogen…. 😉