I decided to stop riding my big bike and get back to my mountain biking roots when the pandemic struck.
Today I will show you how I have optimized my bikepacking bike for my current backcountry adventures.
Even if you don’t like mountain biking or bikepacking I hope you will learn about frame design, suspension setup and tuning to get the best performance from a full-suspension bicycle.
First, I need to know how I ended up with a long-travel Enduro bike for bikepacking.
A bikepacking bike for a very specific purpose
It’s not an exaggeration for me to say that Oaxaca is the best place for gravity mountain biking in Mexico.
Sierra Norte, a mountain range located behind Oaxaca, has more than a dozen trails that drop 1000m (3300ft) or higher. Many of the trails were created over thousands years as ancient routes that ran through the mountains, and took the most direct route to get from A to B. Trails are often rugged, rocky and steep.
My current goal is to discover as many ancient trails as possible. The best way to do this is by riding an enduro bicycle.
My Enduro Bike Criteria
These are the minimum requirements to find a bike that can handle technical terrain and steep hills.
Full suspension bike with over 160mm travel for traction on the most difficult trails.
A head tube angle of 63-65 degrees to allow for a long front center length and desired steering characteristics.
My front wheel will remain planted on steep climbs with a 78-degree effective angle seat tube angle
To suit my long arms, I have a long frame reach of 510mm+
Dropper seatpost allows me to place my body weight anywhere I want between my front and back tyres.
I was able to get a stock alert for a bike that I liked (Nukeproof Mega 289 Comp), and I clicked buy. It was then shipped to Mexico.
Geometry of the Nukeproof Mega 290 Frame
Let’s begin with the Nukeproof Bikes Mega’s frame geometry. The Mega is built according to the modern mountain bike mantra “long, low, and slack”.
You can increase the wheelbase length (longer), lower the bottom bracket height, and reduce the head tube angle. This will create a bike that is:
1. It has a lower centre of mass than other bikes. This makes it more stable in steep terrain.
2. This increases your front endo angle and makes it more difficult to pitch over the bars after hitting root or rock.
3. This feature provides a high-tech trail figure that acts as a stabilizing force to straighten your steering once your front wheel is removed from the line.
This geometry can make it difficult to climb steep, technical trails and narrow turns. My climbing is mainly on fire roads.
You might think that my 64-degree bike is too heavy because of the low head tube angles. It is not true. I use an 800mm handlebar with ample steering leverage to overcome the steering, front bags weight, and low front tire pressure.
You can get an idea of how much leverage a slackbike handles well by riding with your hands inboard. The reduction in steering control is enormous.
One downside to a slack bicycle is that it can cause wheel flop. This is a destabilizing force that pulls your front wheels to the right or left when you are riding at low speeds. This effect is reduced by steering leverage, but is still noticeable when I climb.
Climbing is made easy by the steep effective seat tube angle at my back. Because my center of mass is farther forward than on other bikes, my front wheel won’t lift up when I’m climbing 15% inclines.
Okay, let’s get on with the suspension.
How I Optimised My Suspension
Mega offers 170mm (6.7″”) travel at the front and 160mm (6.9”) at back. The shock and air fork can be used together. This is great for bikepacking, as I can add or subtract air depending on whether I have luggage.
The Mega was designed to descend. Frame design allows for the rear shock to be active under rear brake (low anti-rise), especially if it is deep in its travel. This characteristic is very useful for me on loose and chunky terrain, as it allows my rear wheel to grip the best.
The rear shock is too active when riding uphill. It bounces up and down more than I would like. (The bike has low anti-squat value). To save money, the Mega’s Mega model doesn’t have a compression lockout switch.
This may not sound like a great idea, but it’s what I did!
The shock’s return speed from impact (rebound) is slowed down, which reduces the suspension response. Then, I ride fire road climbs at a fast cadence to prevent my shock’s travel from getting too slow. It is a very efficient solution.
The shock damper tune is great for descending. It is very well-suited for my bike and weight. My shock has been set up softly for loose terrain. This helps maximize traction and reduces bumps. This shock works great on trails because there aren’t too many gaps.
The fork performs well, but could be more. To get the best small bump compliance and grip, I run it again softly with zero compression damping.
It sits a bit deeper in its travel than I would prefer. It would be more comfortable if it had more compression damping, but the clicks on these bumps are too harsh.
I would be able to tune my fork better with a more sophisticated suspension damper (high-speed compression adjustment in particular). A Rockshox damper upgrade kit with greater tuning capabilities is available, so I may get one.
How I Optimised My Tyres
The Oaxacan trails are loose and scrambly so I can’t push my tyres into corners to increase grip. These conditions call for aggressive tread patterns and lower pressures.
Low tyre pressures cause my tyres to deform more, which increases the contact area and ground grip. This reduces my effective spring rate, which gives me more grip on bumps of high frequency.
A lower tyre pressure optimizes grip, but that’s not all. Your tyres are key to increasing bump compliance. This reduces the trail’s ‘harshness’ for your hands and upper body. Low tyre pressures allow me to reduce the distance or speed my handlebars travel over bumps. This results in less fatigue and arm pain.
Schwalbe has teamed up recently with me to dial in my tyre set-up. We tested tyre models in various widths, tread patterns and rubber compounds.
I decided that a 2.6-inch wide tire would be the best for this terrain, since I could use lower pressures to improve grip and reduce fatigue.
Strangely, my most aggressive front tyre, the Schwalbe Magic Mary was not giving me enough grip when cornering on soft surfaces, compared to my outgoing 2.5” tyre. My front tyre was even able to handle this at 11psi/0.8bar!
Although I was initially confused, I believe I have it figured out. The tread pattern becomes too wide when the tire is sized up from 2.4′” to 2.6″. My front grip problem was solved completely by switching to a model with 2.4” and 15-16psi/1-1bar.
Schwalbe sidewalls are also very stiff. This gives them more puncture protection and helps prevent sidewalls collapsing in tight corners. They ride at higher pressures and are more harsh than other tyres.
My previous Michelin front tire had almost half the ‘harshness’ of my current Michelin model, but with 22psi rather than 15psi tyre pressure. You will need to test pressure before switching between tyre models.
I settled on the Schwalbe Big Betty rear tire. The 2.6″ version is my favorite, and I use it at 17-18psi. On rockier, harderpack trails, the less aggressive Schwalbe models were fine, but the Big Betty is my only choice when the surface is uneven.
Okay, so you are probably hearing me talk about my low tyre pressure. You might be wondering why I don’t roll my tyres off my wheels and turn my rims into stones.
Tyre inserts: The benefits
To reduce tire pressures, I fitted Schwalbe Procore tyre inserts on my bike.
Procore can be thought of as an extra road bike tire that fits inside your mountain bike tire. An inner tube allows you to choose whether to inflate your inner or outer tire.
My rims are protected from impacts and pinch flats by using tyre inserts. Instead of the rock hitting my rim directly, the rock will bounce off the inner tire. To get more grip and comfort, I can use lower pressure tyres without threatening to damage my rim.
Procore also applies outward pressure to my tyres locking the bead to their rim. My Michelin tyres used to ‘burp’ on rocks, losing little sealant and air pressure. Procore eliminates this problem.
Procore’s tubeless setup is made easy by a hand pump. I only need to inflate half of the inner tire first. This allows me to seat the outer tyre at the rim with minimal compressed air.
Finally, Procore makes it easy to change tyres. The inserts are smaller than foam inserts like Cushcore and take up very little volume. You can also easily maneuver your tyres so that you can get them on or off. This system is faster than tyre inserts and I can change my tires just as quickly.
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