Words and Illustrations by Geoff Wright.
If you’re in the market for a different bike then you may be overwhelmed with the share amount of numbers you have to take into consideration. Looking into these numbers can be a good and bad thing. It may mean you’re starting to learn from your previous bikes and are finally realising that these numbers have a slight correlation to the quality, comfort and nature of your 2 wheel stead. Or it may mean you’re completely over thinking it and you should just ride anything you can get your hands on. I tend to lean towards the first options because designers, engineers and project managers have slaved for countless hours to come up with the geometry, spec and price numbers of each bike they bring to market.
Price
Let’s kick things off with Price as it is usually the biggest factor when buying a new or used bike because you can either afford it or you can not. You have probably seen the steep rise in bike prices over the past year and a half and may be thinking, why is that bike 12k and that one 5k, they look like they do pretty much the same thing? You may have even heard of the term brand tax being used, which is street talk for, “I haven’t got a clue why it’s more expensive than other bikes”. Hopefully we can clear a few things up by shining some light on the intricacies of building a bike and a brand.
Price has four subcategories, Product, Culture, Marketing and Demand. Notice how only one of those categories is actually relevant to you riding a bike, however they all go hand in hand to create the price you pay to own a bike.
Product
Some brands are committed to driving the design, technology and innovation of the mountain bike industry forward and other brands wait to see what these trend setting companies do and then bring it out a few years later. Emphasis on the manufacturing quality goes a lot further with high end brands who insist on making a quality product that will last through years of abuse. It also cost bike companies more to use factories who treat their employees and our planet with enough care to pass audits and achieve certifications. It’s often the case that when something is cheap, the environment and worker is being abused.
Culture
If your favourite bike brand has a multi tare sponsorship program that assists hundreds if not thousands of riders across the globe, then these are costs can start to build up. Although some athlete may only get one bike, other top tare athletes may get 2-3 bikes, their flights and expenses paid for by you the tax payer. Just remember, these are the riders who might inspire you to ride better or who are local riders you want to get behind to win the next race in their code. Buying from their sponsors helps them do what they do best. As well as competition ambassadors there are cultural ambassadors who are driving the wider mountain biking community forward and strengthening our sport. These individuals and their activations need funding and you guessed it, you pay for it. So, if you like what a brand is doing to support your local community or communities further afield, then it would be logical to support their brand and buy their bikes new or even used.
Marketing
The fact that you know about the bike you are looking to buy is almost certainly because of the brands marketing. Then they have to make amazing videos and graphics to explain the technology to you in a way that won’t put you to sleep and to prove that this new bike will make riding so much easier and more pleasurable than the bike you already own. Is it smoke and mirrors or is it just a company trying to do some justice to their employees who have brought yet another master piece to market? Marketing sucks until you’re interested in the product but the more marketing they do the more the price of your bike goes up.
Supply & Demand
If you thought marketing sucked, supply & demand is its feral cousin. This can drive the price of your bike up simply because they didn’t make many and people want it. When there is a shortage of something prices often go up and this is a massive reason why bike prices are higher now. Everyone has been trying to avoid the plague so they dusted off their old Huffy and bombed round on it. They hated all the squeaking and the headset play so the bought a new bike driving demand through the roof and even brands with large supplies didn’t need offer competitive pricing to attract buyers.
Any or all these factors could be considered when aligning yourself with a brands values and ultimately buying a bike. Maybe you want a low-tech bike, that’s made from the finest grade alloy tubing money can buy, in an accredited factory and you had to search high and low for it because they spend little to no money on marketing. Or maybe you want to buy an unnamed frame from ali-express, made under questionable circumstances and fit it out with AXS and Fox factory all round. There are so many ways to buy a bike but there is an art to finding one that aligns with your values, body and riding style.
A simple way to think how prices are established is a radar graph. The more yellow you see the higher the price might end up being. The exception lies in those bike companies who are having their cake and eating it too. What do I mean by this well, some bike companies have a small array of ambassadors, produce bikes with dated innovation but market the shit out of them to make sure they fetch a price similar to that of a brand with a more balanced radar graph. This sounds stink but it’s nothing new, it happens in every industry. If you care you just need to do your due diligence to make sure you’re supporting the company that matches your own values.
Geometry
I attempted year 13 calculus and unfortunately it didn’t go very well for me, and well long story short now I have to test and write about mountain bikes too scratch together enough pennies to make tofu quinoa salad for the next potluck dinner, life’s tough. I thought my poor grades in Calculus were the reason I struggled so hard to understand the tables of geometry of each bike but apparently, I wasn’t alone in this battle. Many other dried-up mathematicians come mountain bikers struggle to decipher these mysterious number puzzles. So, let’s try to set the record straight and run through some of the most important values and the difference they make to the fit and feel of any given bike.
Head angle
It would be rude not to start the ball rolling with HA. This number in degrees can have significant influence over how your bike performs during the ups and feels during the down. Slack head angles make for faster cornering and higher stability during descents plus this makes a bike centred and more confidence inspiring in steep terrain. The slack angle also helps absorb shock more effectively because the forces are more aligned with travel of the suspension. Steeper head angles make for more efficient climbing by keeping your weight over the front wheel, stopping it from floating around. Steeper angles also have faster handling and feel better on flat terrain.
Seat Tube
ST is next up on the plate and is very trendy right now for one reason. Steepening the seat tube angle will increase the performance and efficiency of slacker head angle bikes during climbs. Having your saddle over the bottom bracket not only makes pedalling easier but pulls your weight forward to stop the front wheel wondering so much on climbs.
Reach
Seat angle will affect your effective top tube (ETT) length but will not affect your reach, hence reach has become the new gauge of a bikes length and how it will feel while standing/descending. Reach uses the same measurement line as the ETT but draw a line vertically up from the BB and where it intersects the ETT line is the start of the measurement. Modern bikes have been getting longer reaches, allowing riders have shorter stems and still move further forward to into the attack position without being too far over the front end. Essentially the growth of this measurement is favouring aggressive riding. Short reach numbers will make the bike feel more upright which may be a bonus to some but to most riders you want a bike with the right amount of reach to allow you perform better during descents.
Stack
You can’t talk about reach without talking about stack because stack is the length of the vertical line that ascends from the BB to give you your reach. Stack is most relevant to shorter riders who don’t want their handlebars feeling too high and for XC riders who want to get low to obtain a better aero position and improved climbing performance. Low stack can be disadvantageous if you lack flexibility in the lower back and hips.
Chain stays
These are also all the rage at the moment because reach and head angle evolution has pushed wheelbase number higher, shorter chain stays (circa 430mm) have been introduced to create bikes with more playful rear ends. But if stability and climbing performance are what you’re after then look out for longer stays (circa 460mm).
Wheelbase
The last number we’re going to talk about is wheel base. This is the distance between the two axles. Longer wheelbases provide more stability at high speeds but can be a bit cumbersome to manoeuvre in slower tighter situation. Wheels base although a frequently over looked number can be a good gauge of how a bike it going to behave and where on the mountain it will exceed. It’s important to remember what is affecting the wheel base, look closer at the chain stay, reach and head angle numbers to figure out where things are shorter and longer and this will give you an idea of how the bike will feel and ride. Short chain stays but slack head angle bikes might struggle to climb, where steepening the head angle and lengthening the chain stay will negatively affect descent performance and the playful nature of a bike.
Fork Offset & Trail
This measurement seems riddled with debate and controversy because there is so much going on in front end of a bicycle. Rake or offset is the distance between the steering axis/head angle line and the centre of the front axle. The simplest thing that offset affects is the wheelbase, but this is often only a 5mm difference. The main difference is how a shorter offset increases the trail of the front wheel. Longer trail results in steadier and slower handling.
Specification
When you think of spec you usually think of things that you can change to suit you as a rider. You might want narrow bars, wide rims and 6 pot brakes because you believe this is the best combination for your style of riding. For the most part that is true but there are a few numbers that can not be changed without really messing with your bikes performance and geometry.
Wheel size
There are three common wheel diameters, 26, 27.5 and 29. As I’m sure you’re aware, 26” is the original wheel size, used to great effect back in the early days of the sport when the riders of the time took their beach cruisers to the mountains, these are what we would now call klunker bikes. This now almost obsolete diameter is the strongest and lightest of the three because the spokes are shorter and the diameter is smaller creating a more resilient wheel with less material. 26” is a great size for tight terrain because the smaller diameter can turn quicker and with less effort.
29” has been a staple in XC and with less technical riding for a while. As the largest wheel size it is the heaviest and weakest but has been able to make it up in other areas. DH and enduro have started taking notice of how this diameter performs in rough terrain and its effective roll over. 29ers also offer improved grip because of the larger surface area of tyre touching the ground, resulting in riders running faster tyres without compromising on cornering performance.
27.5 came in with a bang because it bridges the gap between strong and lively 26ers and fast and controlled 29ers. This inbetweener was predominantly adopted by enduro and DH because they were stronger and had better handling than 29s while being more composed and smoother in rough technical pieces of trail when compared to 26ers.
MX. undoubtably the biggest trend in mountain biking right now is the purpose build mullet bike which features a 29r upfront matched with a 27.5 in the rear. The roll over and grip of the 29er up front mixed with the composure and strength of the 27.5 in the rear is one of the smarter decisions the innovators in the bike industry have made in a while.
Hub spacing
Just like wheels, hub spacing keeps changing. Widths have gone from the old standard of 135mm, to the new standard of 142mm, to boost spacing at 148mm to super boost at 157mm. It’s claimed that the increase in hub widths is a result of the growth of wheel sizes from 26-29” and is an attempt to achieve optimal lateral stiffness.
But how is this achieved, essentially it’s all to do with how the relationship between rim width and hub spacing effects the spoke bracing angles. If you run 29’ rims on pre-boost 142mm hub then you create acute spoke bracing angles. The wider nature of boost and super boost hub flanges increase spoke angles, creating a more stable base. Basically engineers are trying to get the 29’ platform close to the strength and stiffness of a 26’ wheel. But the benefits don’t just lie in the strength, wider spacing means shorter chain stays can be achieved and pivots become further apart making them stiffer also.
Brakes
I assure you these numbers are little easier to understand than those associated with hubs. The main unit to look out for is the number of pistons. Pistons, or pots as they are commonly called, are the cylinders that press the pads into either side of the rotor to create friction and ultimately stopping force. There is two, four and six pot braking systems which offer a range of performance for any rider. Two pot brakes are light and commonly used for applications that require less braking power. If you’re after more reliable and consistent braking performance you will usually be looking for four pot brakes with are more powerful and can deal with the heat of intensive braking situations. Six piston brakes take this a step further and also let you run larger pads giving you even higher braking performance.
