If I had a pound for each time I’ve been requested “What’s the perfect body materials for a motorbike?” I’d be capable to afford most of a Rocket espresso machine.
The reality of the matter is, this isn’t an easy query. The reply relies upon very a lot on what the rider goes to make use of the bike for, the place they’re going to journey it, how are they going to journey it, how lengthy they wish to hold it and what their funds is.
Let’s begin by operating by means of the standard suspects, and itemizing off the generally accepted truths about every body materials.
Biking Weekly’s Undercover Mechanic might be publishing his ideas on the state of the business as soon as a month. He is been working with bikes for over 20 years, providing servicing on fashions from a few of biking’s finest (and worst) marques. You will discover him in any respect main commerce reveals and occasions, simply do not count on him to make himself identified.
Metal is actual
Metal is commonly the selection of customized body builders
(Picture credit score: Adrian Wills)
Firstly, we have now the venerable metal body. Bikes have been just about first made in metal (wooden really, should you’re counting pastime horses however I’m speaking about Starley’s Security bicycle), however the materials has advanced in step with how lengthy it has existed in bike frames. I’d be tempted to say that fashionable metal tubes for bicycle frames are a number of the most extremely manipulated tubing cash can purchase; it’s just about the norm for even an affordable metal tube to be internally double butted, chilly drawn and warmth handled. All these processes culminate in making a tube which is each extremely robust, resilient to fatigue and comparatively gentle.
The massive advantage of metal is that it’s straightforward to fabricate a bicycle body from it which is why it’s the materials of alternative for almost all of customized body builders. It means they will construct an amazing bike, in customized geometries that don’t price the Earth.
The draw back of metal tubing in many individuals’s eyes, is that resulting from its density, it weighs greater than many of the different supplies on this record, which isn’t to say the frames weigh extra, however we are going to come again to that later.
Aluminium has come of age
The Specialised Allez is without doubt one of the highest profile aluminium bikes
(Picture credit score: Future)
Subsequent on the record, we have now aluminium. Aluminium grew to become the fabric of alternative for racing highway and mountain bikes within the late 80s and early 90s with firms like Cannondale and Klein main the way in which. They quickly grew a fame for big tube sizes, unimaginable stiffness and light-weight weight. The frequent drawback with most of those early aluminium frames was that they didn’t fatigue effectively. I bear in mind racing the Malvern Traditional mountain bike race and watching as quite a few riders walked over the end line with their new unicycles as the pinnacle tubes had sheared off.
The most recent race content material, interviews, options, opinions and professional shopping for guides, direct to your inbox!
Trendy aluminium frames have largely received over these issues with cautious tube manipulation by means of processes resembling hydroforming and warmth treating. They now appear to type the vast majority of the cheaper price factors in highway bikes and mountain bikes as a result of relative gentle weight, stiffness and ease of manufacture. Simply don’t look into the power required to get aluminium out of Bauxite if you wish to really feel smug about your new Inexperienced pastime.
Titanium is the fabric for a ‘perpetually’ bike
Titanium frames climate the storms effectively
(Picture credit score: Future)
Subsequent in line within the record of metals is titanium. Usually admired for its skill to climate any storm resulting from its chemical inertness, titanium has develop into a favorite for winter bikes, particularly in additional temperate climates. It has a fame for being as light-weight as aluminium however as robust as metal, with a capability to take in vibration giving a cushty journey. The issue with titanium is that it’s extremely onerous which makes it tough or very costly to govern the tubes in any option to alter the journey high quality. Which means that cheaper titanium bikes are usually comprised of what we name plain gauge tubing, that means the thickness doesn’t change by means of the entire size of the tube.
Usually, if a tube goes to interrupt, it can all the time be at one of many joints that means that you may make the fabric between the joints thinner. That is referred to as butting, which not solely saves weight but additionally alters the way in which that tube reacts to highway vibration and fatigue.
As a result of titanium is so onerous, it’s extremely tough to butt the tubes by regular means, which is usually chilly drawing tubes by means of mandrels or swaging them. A bit bit like squeezing Play-Doh by means of a mould. Some extremely courageous smallscale builders have been identified to place plain gauge tubes onto a lathe and skim off the surplus materials and a few larger firms do it by way of a centerless grinder, but it surely’s nonetheless extremely wasteful because it’s eradicating materials to waste, therefore the sometimes related pricetag.
Carbon is King for the plenty
Carbon begins its life as a cloth sheet
(Picture credit score: Getty Photos)
Then lastly, we come to carbon fibre. This begins life as a cloth sheet, comprised of carbon strands, which is both woven and described as 3K, 6K et cetera or unidirectional, which is basically matting manufactured from strands of carbon. Very similar to chopped strand glass fibre with a flowery identify.
An epoxy resin is soaked by means of the carbon materials and it’s sometimes positioned right into a mould to treatment and harden into inflexible carbon fibre. The excessive energy properties everybody loves about carbon fibre comes from the connection between the fabric and the resin which is usually generally known as the interface.
There are two methods to make bicycles from carbon fibre. Firstly, you may take or make tubes after which minimize them to go well with the geometry of the body you’re making, identical to you’ll with a metallic body. These tubes can then be joined along with somewhat further materials and resin, identical to a lug on a metal body. This tube-to-tube development provides you the advantages of carbon fibre with the power to nonetheless make customized geometry, though it is a bit more labour intensive.
The opposite manner is to pay £100,000 plus for a mould after which lay sheets of carbon into that to create part of a body. Any moulded carbon body is usually made up of 5 or extra elements. In lots of circumstances, every body dimension will share a few of these elements with its adjoining body sizes, which is why should you have a look at geometry charts of manufacturing carbon frames and plot the stack and attain on a chart, it could not be linear however stepped, as a result of constraints of the moulds being shared. This methodology is nevertheless a really economical option to produce first rate high quality frames on a mass manufacturing scale. It’s a bit like these moulded popout surf boards everyone learns on earlier than shopping for a handshaped board. It’s why we sometimes refer to those within the workshop as ‘plastic popouts’.
Now I’m absolutely conscious that I’m being overly essential. It is as a result of I’m an previous git and I hanker for the times when each city had its personal body builder and folks rode round on bikes that fitted them completely, however you must admit that the low value for the relative excessive efficiency of low-cost carbon frames has received an enormous quantity of individuals into biking.
The strange
Bamboo has been used, on a small scale
So we’re virtually on the finish of our record of body supplies. I haven’t actually touched on a number of the strange stuff resembling magnesium. Magnesium may be very plentiful, with sufficient to be present in one cubic meter of seawater to make a bicycle body, or so the advert males would have us consider, however the bikes had an odd tendency of falling to bits underneath stress.
There was additionally a pattern for metallic matrix composites within the 90s, spearheaded by the likes of Specialised with their M2 bikes, however the prices of manufacture grew to become prohibitive and was quickly overtaken by the then-new-fangled carbon bikes.
There have been just a few different strange supplies, resembling bamboo, which can be utilized to make bicycle frames however I believe plenty of the innovative proper now’s in 3D printing and mixing supplies for optimum advantages. I just lately noticed a Bastion and a Festka side-by-side, the Bastion with its 3D printed titanium lugs and carbon tubes sitting subsequent to the Festka with its titanium tubes and carbon fibre lugs. With out bodily bench testing these with costly measurement instruments it could be fairly onerous to say one was higher than the opposite.
The underside line…
Tyre alternative and the quantity of uncovered seatpost might characterize a better distinction
(Picture credit score: Anne-Marije Rook // Future)
I believe that brings me neatly to the principle level right here. If I have been to get well-made examples of every body materials and journey them side-by-side, the most important variations can be offered not by the body materials however by the size of the seatpost protruding from the body and the stress of the tyres. When you think about the double diamond design of most fashionable bicycle frames, it’s an extremely environment friendly construction. Should you analyze the quantity of flex in every triangle, it could be barely perceptible.
The seatpost then again is a cantilevered beam sitting at an angle with round 60% of your weight resting on it. So in case you have plenty of seatpost protruding out of your body, it’s going to flex extra. Canyon and Ergon know this and produce seat posts which can be basically carbon leaf springs.
Additionally, with the trendy pattern in the direction of giant tyres and decrease pressures, these have much more influence on our sensory notion of how our bike feels as a result of elevated ranges of grip and shock absorbance. If I have been being cynical, I’d recommend that the rationale disc brakes have been accepted so readily by mass-market producers, was as a result of they facilitated using a lot larger tyres, enabling them to easily make the frames gentle and stiff with out having to fret about including any consolation by means of intelligent supplies engineering.
So again to the query at hand, what’s the finest body materials? Titanium and metal, particularly the brand new stainless steels, final the longest. Aluminium will give an amazing stability of light-weight and low price whereas carbon fibre will sometimes be comparatively gentle and could be comparatively cheap however received’t final as lengthy as a result of interface between the carbon resin ultimately breaking down.
Remember, although this Venn diagram overlaps fairly massively. I personal a metal bike which weighs slightly below 7kg and we see loads of carbon bikes which weigh a few kilos greater than this.
So I assume my recommendation can be this, don’t write off any specific body materials primarily based solely on its fame. How effectively the body matches you is the extra vital factor in addition to how lengthy you need your funding to final.
Now, the place did I go away that Aeropress….
