Although the term ‘endurance road bike’ is relatively new, the concept has been around the cycling industry for quite a while. When it comes to long days in the saddle, or a more forgiving ride over winter, then an endurance road bike is ideal. Geometry wise, it’s not as aggressive as race bikes such as the TCR or Propel range, but what does this actually mean? Below, we look at what goes into making an endurance road bike and the small changes that make a big difference to how an endurance bike rides.
What is stiffness?
Stiffness affects how the bike responds when putting power through the pedals – a more flexible bike will ‘waste’ energy by contorting, rather than directing it into forward motion, essentially making you slower for the same effort than a stiffer bike.
What is compliance?
Compliance is the frame’s ability to smooth out the road and absorb the bumps and imperfections. It’s important as a compliant bike will be easier on the body to ride, and is a hallmark of a good endurance bike.
Why Does It Matter?
No bike can be both the stiffest and most compliant – it’s just not possible. It’s where the bike sits on the spectrum that makes all the difference on how it rides. A super stiff race bike won’t be very compliant, which means the ride will be harsher. Fine for an hour or two of racing, but longer rides require something that’s easier on the body.
At Giant, we add a degree of compliance to the entire range, so even the top end race bikes won’t destroy you after an hour – however there’s certain models which are engineered with more compliance than others to give it a certain riding characteristic.
On first glance, a geometry chart can just look like a load of numbers chucked onto a table; however they are the result of decisions refined over years of experience and manufacturing that lead to the perfectly tuned machines on the road today. It’s tempting to focus on the numbers in isolation, however the whole package must be considered when comparing bikes as a small change in one area has a huge knock on effect elsewhere. Despite that, we can pick out a few key indicators of endurance road bikes and assess how they compare to another road bike.
Below, we have the geometry charts for the Propel Advanced pro and the equivalent Defy. They are quite similar and share common features; however there are a few noticeable differences which we can look into that separate a race bike from the endurance bike.
2018 Propel Advanced Pro Geometry Chart
2018 Defy Advanced Pro Geometry Chart
Head tube length
One of the crucial indentifiers of an endurance bike is looking at the head tube length. A longer head tube results in a more natural upright riding position, ideal for rides where speed isn’t essential. The longer head tube also helps in dampening vibrations from the road, as there is more frame material between your handlebars and the ground, therefore it is a common trait on endurance road bikes. If we take the Defy, the Medium size has a 165mm head tube, compared to the propel which sits at 140mm. This extra 25mm raises the natural riding position of the bike away from the racier Propel, giving a slightly more upright ride.
Head tube angle
This brings us nicely onto head tube angle – a classic race bike design has a head tube close to 73 degrees, which makes the bike more responsive as a steeper head angle makes the steering faster. The Defy sits at 72 degrees, which slightly slacker. This small change in the angle results in the bike having more stability and control under steering, compared to the ‘twitchier’ racing bikes. When it comes to endurance, it’s all about control over long periods of time rather than short sharp blasts.
Fork Rake & Trail
By affecting the head tube angle, this knocks on to the ‘rake’ of the fork (also known as offset, which is the difference between the centre of the wheel and the centre of the steering axis) and the trail (difference between the steerer axis and where the wheel contacts the ground). More trail provides increased stability at higher speeds. The numbers are similar for the Propel (57mm) and the Defy (60mm), with the small increase making the Defy just that little bit more stable.
Another critical measurement is the chainstay length. The Defy features 15mm longer chainstays than the Propel (420mm compared with 405mm). Shorter chainstays are common on race bikes, as it improves the acceleration and climbing ability, whereas longer chainstays are perfect for bikes that need better tyre clearance and the ability to mount fenders – an essential for any endurance road bike.
What difference does it make?
This is all well and good, but what does it mean in real terms? Well, the resulting changes give the bike nearly 20mm more wheelbase (measurement from wheel to wheel) on the Defy compared to the Propel. A longer wheelbase provides a more comfortable ride. It also improves stability – think about your feet, the closer they are together the less balance you have. If you take a wider stance, you instantly gain more control and stability, which leads to the bike having a ‘planted’ feel when on the road compared to racier set ups.
It’s Not All About Geometry
Whilst the geometry is one of the key aspects of how a bike rides and handles, the entire set up must be considered when categorizing whether a bike is more suitable for endurance riding. Simply focusing the geometry and ignoring the chainset, wheels, tyres, saddle and all the other components isn’t giving you the full picture. It’s possible, through bike setup and accessory choices, to make a bike more endurance orientated –pro riders put 28mm road tyres and double wrap handlebar tape at Paris Roubaix – but without the geometry, it will never quite beat the dedicated endurance bike.
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