Gravel bike basics: The most important aspects of the all-rounder

Not all bikes are the same: from geometry and tyres to riding technique, gravel bikes also have their own special characteristics. In order to handle your new bike properly or to make an informed purchase decision, you need more than just information about the brands of the individual components. What do certain figures mean? And what should you look out for? To accompany our big gravel bike comparison test, we have summarised the most important aspects of these all-rounders.

Geometry

Don't be afraid of gravel bikes! That's the message here. A common reaction to this type of bike is: "I couldn't sit like that!" By this, colleagues and friends mean the position of the saddle to the handlebars and the idea that you have to support an insane amount of weight with your arms! But that's not the case at all with a suitable, well-adjusted bike. As an experiment, we put a kitchen scale between our hand and the handlebars and, sitting relaxed, it showed less than two kilos. Even on even longer-stretched road bikes with even sportier saddle raises, an experienced rider can take their hands off the grips without tipping forwards.

And gravel bikes are a lot more comfortable than road bikes and even their closest relatives, the cyclocross bikes. The graphic above shows one such bike, the Inflite from Canyon. In comparison, the Grizzl (below) from the test is visibly more comfortable or, better, less sporty. Cyclists who are used to a riding position with a little more upper body support find it more comfortable. It is also more due to a lack of mobility in the hips than to the weight of the hands if you find the position uncomfortable when trying out a gravel bike. In the vast majority of cases, this disappears with familiarisation and a little stretching.

>> You can find an overview of the 12 gravel bikes in the test in our article on the big all-rounder check <<

Biomechanics

Biomechanically, the posture on such a bike is not only more efficient, but - attention! - can be healthier! The slightly forward position of the upper body means that its centre of gravity is directly above the cranks. You can use it as an abutment, so to speak, and pedal much harder than if you sit upright and pedal in front of the centre of your body. If you want to climb a high step on foot, you automatically adopt exactly the same position as on a gravel bike. And the balanced weight distribution ensures that impacts from below are absorbed by the legs and arms rather than the spine.

Different sizes and measuring points

The seating position on a bike is defined by the relationship between the height and length of the frame. In the two diagrams you can see, among other things, two decisive variables and their measuring points: the Stack J and the Reach I. With the pedal crank as a fixed point, they provide information about the distance to the steering in the horizontal and vertical planes. You could also have used the Top tube length C or Saddle height A but since the saddle can be adjusted in both planes, experts use fixed values for the former.

For you as a rider, the decisive factor is the stack/reach ratio, which ultimately indicates whether a frame is made for more or less upper body support. That's why we have the SR quotients in all test boxes. The values are around 1.5 and slightly below, even small changes make a big difference here. The smaller the number, the sportier the frame. We have also specified the Wheelbase H. Within gravel bikes, it differs only slightly; specialised touring bikes, for example, are four, six or eight centimetres longer.

This means that they run more smoothly in a straight line and you don't waste energy on slight serpentines. On the other hand, their steering behaviour is super sluggish. Gravel bikes are a great compromise here too! Their forks are (almost) straight and the Steering angle slightly steeper (E) than trekking bikes, which makes them more manoeuvrable and controllable off-road, but the frame triangle and rear triangle are long enough to prevent bumps on long straights and with luggage.

Gravel tyres

Alongside the geometry and construction of the frame, the tyres are the component that has the greatest influence on the individual qualities of a gravel bike, but they cost a fraction of the price. You can therefore influence a lot by changing the tyres either at the time of purchase or afterwards, but almost always to the detriment of the opposite characteristic. The tyre should match the basic characteristics of the bike; a chunky, 50 mm wide tyre on the Storck, for example, would have been a shortcoming. A rough overview of the tyre types fitted to the test pool can be found in the picture gallery above. And in order to be prepared for a possible technical discussion with the salesperson, training partner or mechanic, here are a few of the most important terms and "must-knows":

• Tyre sizes: Virtually all gravel bikes have 28-inch rims, recognisable by the lettering "700 x or 622 x" on the tyre, very rarely very thick tyres require smaller 27.5-inch or then 584 rims. After the x is the width/thickness, gravel tyres should have at least 40 mm. The thicker the tyres, the larger the contact area and grip with the same tread and pressure. 50 to max. 55 mm wide tyres also dampen better, but they roll less smoothly and are slower to accelerate and turn in.
• Profiles: The structure and raised profile are the most visible elements. Slick tyres without tread only occur here if you buy a second set of wheels to switch to road bikes. For increased road use when commuting or touring, bald tyres are very suitable - these are tyres without tread along the tread and more pronounced on the sidewalls. Negative tread patterns with channels carved into the rubber are good on wet roads but quickly become clogged off-road. Studded treads are common on gravel bikes; the closer the cylindrical bumps are, the better they roll, and the wider they are, the better the grip on loose ground. Coarse studs work best here, but they generate rolling resistance and rolling noise on hard roads.
• Hose: The test bikes came with a classic inner tube, but the trend is towards tyres with a screwed valve, but "tubeless", which roll more smoothly, are lighter and supposedly less prone to punctures. Our experience has been rather negative, especially for those with little technical experience and all-round use. Tip: ultra-light, stable inner tube made of Aerothane from Schwalbe or theTubolito use.

Bikepacking with the gravel bike

Gravel bikes have recently proven themselves thousands of times over as an all-purpose weapon for cycle tours and entire round-the-world trips. In principle, any model is suitable for such a trip, but with some you can make the long days in the saddle more pleasant and a little safer. In addition to a frame that is not too hard and a moderately sporty riding position, it is above all the storage points for bottles and panniers that make a gravel bike a touring bike. Threads like the one at the top of the Grizl fork can be found, for example:

• in the large frame triangleideal: fixed points of different heights for large and small bottles
• on the top tubemostly used for small, narrow bags for snacks and smartphones

• on the forkeither for front carriers, drybags or (our tip): large bottle holders
• under the down tubefor the third bottle cage; tip: matching toolbox in bottle shape
• Rear endThread above the rear axle and near the saddle clamp for classic pannier racks or smart racks like on the Focus are much more secure than Velcro bags!

>> Read now: The big comparison test - 12 gravel bikes in an all-rounder check <<

Gears on a gravel bike

For many, the gears are the deciding factor when buying a bike, but this is one of the less important aspects. Three test bikes were equipped with modern, electronic gears; the battery-operated gears with a small, powerful servo motor shift very quickly and precisely and hardly change over time. However, they cost more and of course have to be charged from time to time.

Cross world champion Kluge is completely convinced of the technology, in his experience there are no restrictions at all on gravel bikes due to dirt - and in ours either. Although quite easy to change, you should pay much more attention to the gear ratios when buying. Here are three top tips:

• 2x cranks result in a wider gear range and small gear steps, but the shifting logic/operation is somewhat more complex.
• In the mountains, the lowest gear ratio should be less than 1, 40/44 or 36/40 are good.
• Wide "spreads" of the cassette (difference between largest and smallest sprocket) lead to large differences between two gears; okay for off-road and cruising, unpleasant for sport.

The drop bar or "racing handlebar"

The term "drop bar" describes the design or handlebar shape better than the German term "Rennlenker". Even if the downward-curved handlebar was actually reserved for racing bikes until recently, there are a few reasons why it should not be restricted to ultra-light bikes for the fastest possible rides. First, a mini-glossary on the subject of handlebar shape:

• Handlebar width: For drop bars, it is measured from one brake lever mounting point to the other, in each case from the centre of the tube.
• Drop: This is the height difference from the upper, transverse top link to the lowest grip point on the lower bracket.
• Reach: Attention, frames also have a "reach" value. This refers to the forward curvature of the handlebars from the stem clamp to the foremost point in the direction of travel.
• Flare: It describes the widening of the lower link in relation to the upper part and is between 0 and around 20 degrees. A distinction can also be made between the drop flare and the flare-out, when the lower grip is rotated inwards in addition to the widening, as is the case with bomb track handlebars.

Gravel bike handlebars have handlebar widths of around 40 to 46 cm, in contrast to MTBs, which are offered with over 78 cm. However, as gravel tends to mean gentle terrain, such excess widths are not necessary. And according to Mike Kluge, these wide hand spacings are hardly ergonomically justifiable. Minimally wider than the shoulders - that is the consensus between sufficient control, support ergonomics and aerodynamics, according to the expert. He also doesn't understand why the drop bar with its sometimes extreme flares is so popular. You go to the drop bar to be streamlined, that's what you're working against. On hard descents, however, the lower link is too low. In order to avoid rollovers, you then grab the (narrower) upper part again anyway.

Technical tips for riding a gravel bike

Buying a guitar doesn't mean you can play, and even with the best bike in every test category, you can make mistakes. That's not a bad thing, the bikes are robust enough to fall on their side. However, in order to spare the rider as many crashes as possible, here are four technical tips, carefully devised with professional support:

• Weight distribution is important! Therefore, whenever you brake hard or ride through ditches/holes, stretch your arms and push your bum behind the saddle.
• Only use the front brake very smoothly when cornering! This applies all the more strictly the looser the surface and the faster the ride.
• Do not steer with the handlebars: only initiate changes of direction with them, steering is done by subsequent weight shifts and pressure on the grip of the inside curve.
• In fast bends, put your whole body weight on the outside pedal, your bottom is barely in contact with the saddle.