- \n
- The whole article as PDF<\/strong><\/a> in German.<\/li>\n\n\n\n
- DAV article: Securing while climbing<\/a> in German<\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n
If the belayer is pulled up into the first quickdraw, this can lead to crushing injuries or to a failure of the locking function of the belay device. In addition, the braking distance for the climber increases, which can lead to ground falls or collisions, particularly when close to the ground. <\/p>\n\n\n\n
The greater the weight difference within a rope team, the more difficult it becomes to control the brake strand during lowering. Depending on the situation and the experience of the belayer, it can therefore be useful, from a certain weight difference onwards, to take measures to reduce this accident potential.<\/p>\n\n\n\n
![\"Zaed\"](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb1_Zaed-1024x683.jpg\")
Fig. 1: Devices with wrap angle: Zaed.<\/figcaption><\/figure>\n\n\n\n ![\"Bauer](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb2_Expressi-683x1024.jpg\")
Fig. 2: Devices with wrap angle: Bauer Espressi<\/figcaption><\/figure>\n\n\n\n One way to compensate for the weight difference within a rope team is the use of friction-increasing devices. Various terms are currently in use for these devices, such as friction enhancers, inline resistors, rope brakes or braking aids. In the following article, in accordance with the decision of the standardisation group of the UIAA Safety Commission, we will refer to them as brake assistants<\/strong>.<\/p>\n\n\n\n
Study Overview<\/h2>\n\n\n\n
Prompted by discussions within the standardisation group and by new devices on the market, the DAV Safety Research team conducted a large number of fall tests under laboratory conditions in spring 2025 as part of a scientific thesis. These were supplemented by practice-oriented tests in a climbing gym.<\/p>\n\n\n\n
The following devices were included in the investigation:<\/p>\n\n\n\n
- \n
- Assist (Mammut)<\/li>\n\n\n\n
- Zorro<\/li>\n\n\n\n
- Espressi Basic \/ Lite (Bauer)<\/li>\n\n\n\n
- Ohm 2, Ohmega (Edelrid)<\/li>\n\n\n\n
- Zaed (raed climbing)<\/li>\n<\/ul>\n\n\n\n
How Brake Assistants Work<\/h2>\n\n\n\n
The devices examined follow different functional principles in order to reduce the force that is felt by the belayer during a fall. They can be divided into three groups.<\/p>\n\n\n\n
Increase in friction through wrap angle (Zaed and Espressi):<\/h3>\n\n\n\n
The rope runs around one or more fixed elements with a defined radius. The larger the wrap angle, the greater the friction (Euler\u2013Eytelwein formula). In the case of the Zaed, three different positions\u2014and therefore wrap angles\u2014can be set by adjusting a pin. The Espressi is available with two different brake discs (Basic and Lite).<\/p>\n\n\n\n
Increase in friction through pinching with slot guidance (Ohm):<\/h3>\n\n\n\n
In the event of a fall, the rope is pressed into a slot, which increases friction due to contact pressure.<\/p>\n\n\n\n
![\"The](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb3_Ohm-683x1024.jpg\")
Fig. 3: The Ohm 2 from Edelrid, the newer version of the classic device. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n Increase in friction through pinching by means of a lever (Ohmega, Assist):<\/h3>\n\n\n\n
The tension in the rope sets a spring-loaded lever in motion, which presses the rope against a surface (in the case of the Ohmega, against a roller). The force with which the lever presses on the rope depends on the lever arm. For this reason, the Ohmega, with its three clipping positions, has three braking force levels. <\/p>\n\n\n\n
\n ![\"Ohmega,](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb4_Ohmega-1024x683.jpg\")
Fig. 4a: With the Ohmega, Edelrid introduces a second device onto the market. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n ![\"\"](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb4.1_OhmegaStufen-1024x683.jpg\")
Fig. 4b: Different clipping positions of the carabiner in the sling allow different compensation values (3 levels, marked on the device with +\/++\/+++). Recognising the desired braking level requires some practice. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n<\/figure>\n\n\n\n With the Assist, two different braking levels can be set: either it is clipped into a quickdraw or into a single carabiner. This changes the distance to the bolt and thus the rope path, which in turn influences the point at which the pinching mechanism is activated and therefore the compensation value (see below).<\/p>\n\n\n\n
![\"quickdraw](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb5_Assist.jpg\")
Fig. 5: When using a quickdraw sling (max. 30 cm in length), the compensation provided by the Assist is lower than when using a single carabiner (Boost mode), due to the longer activation travel and the resulting later engagement of the braking mechanism. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n Compensation Value<\/h2>\n\n\n\n
In the user manuals of the respective devices, manufacturers specify the weight difference for which the device is suitable (see Table 1). In not all cases is it clear what these values are based on. Within the UIAA standardisation group, a proposal for a test setup (Fig. 6) is currently being discussed in order to determine an objective compensation value. This value indicates how many kilograms of weight can be compensated by the device.<\/p>\n\n\n\n
The compensation value is determined as follows:
In a first step, a reference test is carried out. For this, at a weight ratio of 1:1 between the belayer mass and the falling mass (e.g. 80 kg to 80 kg), the height to which the belayer is lifted during a standardised fall is measured. The brake assistant is then clipped in at the height of the first quickdraw, and the falling mass is increased until the belayer once again reaches the reference height.<\/p>\n\n\n\nExample with a belayer weight of 80 kg:
If, with the brake assistant in place, the reference height is reached with a falling mass of 95 kg, the resulting compensation value is 15 kg.<\/p>\n\n\n\n![\"Test](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb6_Bremsassistenten-Versuchsaufbau.jpg\")
Fig. 6: Test setup. The configuration of the test setup is based on the following consideration: if the belayer stands 1 m away from a vertical wall (as specified in almost all user manuals of brake assistants) and the device is clipped at a height of 3.10 m (standard height of the first quickdraw in climbing gyms), this results in an angle of 165\u00b0 between the rope entering and exiting the device. In order to avoid the influence of the belayer mass impacting the wall, this angle was created by deflecting the falling mass.
Illustration: Georg Sojer<\/figcaption><\/figure>\n\n\n\nTest Setup and Procedure<\/h2>\n\n\n\n
Using the test setup shown in Figure 6, several test series were carried out starting from a mass of 80 kg and 40 kg respectively. In order to investigate whether a more \u201crealistic\u201d setup would produce comparable results, additional test series were conducted with a modified configuration: the redirect was positioned vertically above the device, and the belayer mass was placed at a horizontal distance of one metre from the device (meaning that the 165\u00b0 angle was created at the rope entering the device).<\/p>\n\n\n\n
The compensation in the case of a fall directly onto the device (which corresponds to a fall onto the first quickdraw) was also determined. In order to take the influence of rope diameter into account, two diameters were selected\u20148.9 mm (Edelrid Swift 48 Pro Dry) and 10.5 mm (Edelrid Tower)\u2014which lie at the lower and upper limits of the manufacturers\u2019 specifications (with the exception of the lower limits for the Ohmega at 8.6 mm and the Assist at 8.7 mm).<\/p>\n\n\n\n
The falling mass was increased in increments of 5 kg up to the value that came closest to the reference height. Among other things, the following were measured: the impact force (force acting on the falling mass), the pulling force on the belayer during a fall (force acting on the belayer mass), and the force at the redirect.
*{{ Julia Janotte is a sports scientist and has been working in DAV Safety Research for ten years. One of the main focuses of her work is safety in sport climbing.<\/em> }}*<\/p>\n\n\n\nResults<\/h2>\n\n\n\n
The compensation values determined are shown in Table 1. One thing becomes apparent: in the fall tests using thicker ropes, significantly higher compensation values were achieved with most devices than with thinner ropes. This must be taken into account in practice. If the weight difference is \u201ctoo small\u201d, the devices will brake correspondingly \u201cstrongly\u201d, which, with static belaying, inevitably leads to very hard falls for the climber and\/or can result in difficulties during lowering.<\/p>\n\n\n\n
![\"Kompensationswerte\"](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Gewichtsausgleich-beim-Klettern_tabelle-1024x881.jpg\")
Table 1:<\/strong> Compensation values of the devices determined in the test setup (Fig. 1). The tests were conducted with a constant belayer mass of 80\u202fkg. With a belayer mass of 40\u202fkg, the determined compensation values were identical, in some cases slightly lower.
* The test series was stopped at a falling mass of 120\u202fkg. With a belayer mass of 40\u202fkg, a compensation value of 60\u201365\u202fkg was achieved.
** The stated compensation values represent the minimum values to be expected.<\/figcaption><\/figure>\n\n\n\nIn the alternative test setups, which were intended to better reflect real-world conditions, the following problem occurred: if the belayer mass is positioned one metre horizontally away from the friction-enhancing device, the resulting pendulum motion leads to strong, uncontrollable swinging. These can significantly distort the measurement results or even cause the devices to deactivate if the belayer mass impacts the wall or swings underneath the device.<\/p>\n\n\n\n
The results of these alternative setups showed considerable variability. Although the measured heights were in some cases slightly lower compared to the original test setup, no clear differences in the results could be identified across all test series in comparison to the original setup.<\/p>\n\n\n\n
For a better comparison of the devices, a series of falls was carried out with a constant weight difference of 10 kg. In these tests, the forces in the rope before and after the brake assistant (Fig. 8), at the redirect, and at the falling mass (impact force), as well as the height of the belayer mass after the fall, were measured. From these forces, the so-called brake factor \u03b2 can be determined, indicating by how many kilonewtons (F1\u2013F2) the force is reduced by the respective device (Fig. 7). It is derived from the Euler\u2013Eytelwein formula and is defined as follows:<\/p>\n\n\n\n
![\"Test](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb8_Bremsfaktor.jpg\")
Fig. 8 Test setup for determining the brake factor. Illustration: Georg Sojer<\/figcaption><\/figure>\n\n\n\n ![\"\"](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/image.png\")
<\/figure>\n\n\n\nThis makes it possible to determine how much force the respective brake assistant reduces in this setup. The brake factor correlates significantly with the measured height of the belayer mass after the fall (p < 0.001, r = \u20130.91, R\u00b2 = 0.83).<\/p>\n\n\n\n
Noteworthy: although the compensation value determined for the Mammut Assist is higher when clipped directly into a carabiner (Boost mode) than when clipped into a quickdraw, the brake factor is the same in both modes. The device therefore always brakes with the same force. The only difference is the point at which the pinching mechanism engages: when clipped into a quickdraw, the longer activation travel delays engagement, which results in the belayer mass being pulled higher.<\/p>\n\n\n\n
![\"Kraeftemessung](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Gewichtsausgleich-beim-Klettern_Diagramm-Brake-Faktor_rot-1024x651.png\")
Fig. 7: Measured values for a weight difference of 10\u202fkg (falling mass: 90\u202fkg; belayer mass: 80\u202fkg).
Red: height of the belayer\u2019s tie-in point [m].<\/figcaption><\/figure>\n\n\n\nFall onto the Device (Active Compensation Value)<\/h2>\n\n\n\n
A brake assistant must also function in the event of a fall directly onto the first point of protection. All devices meet this requirement; only the Zaed provides no compensation in this case, as the rope runs only around the thin pin when the fall occurs onto the device (see Fig. 9). The Ohmega and Espressi show similar compensation values in both active and passive situations, whereas the Ohm 2 and Assist exhibit significantly higher active compensation.<\/p>\n\n\n\n
This can result in a very hard fall. However, when falling onto the first point of protection, the primary objective is to prevent a ground fall, which is why a lack of compensation in this situation is more critical than a potentially hard catch.<\/p>\n\n\n\n
Laboratory vs. Climbing Gym<\/h2>\n\n\n\n
In addition to the laboratory tests, we tested the devices in practical scenarios in a climbing gym. How high is the belayer lifted with a constant falling mass? And can the compensation values determined in the laboratory be confirmed with actual people? The weight difference was adjusted for each scenario using a weighted vest.<\/p>\n\n\n\n
In general, the compensation values determined in the laboratory were confirmed in these more realistic falls. Compared to the reference measurements from the laboratory tests, the belayer was lifted slightly less when using the Espressi; there were also minor deviations with the Ohmega and Assist. However, even with defined and constant parameters such as fall height, static belaying, and distance from the wall, practical tests always involve more uncontrollable variables than laboratory tests\u2014for example, jumping and falling behaviour, as well as belaying technique.<\/p>\n\n\n\n
![\"brake](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb9_Sturz-ins-Geraet-1024x526.jpg\")
Fig. 9 In the event of a fall directly onto the device, the Zaed functions merely like a quickdraw without any compensating effect. The Espressi features friction-enhancing notches on the brake disc. The Assist also has a dedicated slot for this purpose. The Ohmega functions in the same way as it does during a fall onto intermediate protection. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n We therefore assume that the values determined in the laboratory using thinner ropes represent a minimum level of achievable compensation, and that in practice the actual compensation is often higher.<\/p>\n\n\n\n
Fig. 8<\/strong> Test setup for determining the brake factor.
Fig. 9<\/strong> In the event of a fall directly onto the device, the Zaed functions merely like a quickdraw without any compensating effect. The Espressi features friction-enhancing notches on the brake disc. The Assist also has a dedicated slot for this purpose. The Ohmega functions in the same way as it does during a fall onto intermediate protection.*<\/p>\n\n\n\n{{ Lorenz Berker is an engineer (MSc in Mechanical Engineering) and part of the DAV Safety Research team. Outside of testing, he enjoys working with friction-enhancing devices, as well as mountaineering and paragliding\u2014or a combination of the two.
Franz Konstantin Fuss is Professor and Head of the Chair of Biomechanics at the University of Bayreuth. He is a pioneer in the field of instrumented and intelligent climbing holds and walls, as well as in the sensor-based analysis of climbing performance parameters.<\/em> }}*<\/p>\n\n\n\n![\"climbing](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb10_Vergleich-Halle-1024x543.jpg\")
Fig. 10 One of the fall test series in the climbing gym: weight difference 29 kg, static belaying, rope diameter 9 mm. The differing braking effect of the devices is illustrated by the height to which the belayer is lifted. From left to right: carabiner only, Zaed (level 2), Ohm. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n Dynamic Belaying<\/h2>\n\n\n\n
With brake assistants, it is therefore possible, in the case of a weight difference (to varying degrees depending on the device and its setting), to successfully reduce the fall distance\u2014the belayer is pulled upwards less. But what does this mean for the falling climber? The stronger a device brakes, the harder and more uncomfortable the fall becomes for the climber\u2014at least in theory. This was also confirmed by the force measurements in the tests.<\/p>\n\n\n\n
In practice, this means that, in order to make the fall more comfortable, one should actively provide a soft catch (as is also recommended in cases of a large weight difference with a heavier belayer and a lighter climber). In our practical test series, it was possible to give a soft catch with all brake assistants. The measured force at the redirect could be reduced to a similarly low level with all devices by belaying actively and dynamically.<\/p>\n\n\n\n
However, the activation travel of the device must be taken into account, as it can change the correct timing of body-dynamic belaying compared to belaying without a brake assistant. This needs to be considered and requires practice with the respective device.<\/p>\n\n\n\n
<\/strong>Fig. 10<\/strong> One of the fall test series in the climbing gym: weight difference 29 kg, static belaying, rope diameter 9 mm. The differing braking effect of the devices is illustrated by the height to which the belayer is lifted. From left to right: carabiner only, Zaed (level 2), Ohm.<\/p>\n\n\n\nFig. 11<\/strong> Force\u2013time diagram of a fall sequence for active and static belaying using the Edelrid Ohm 2.<\/p>\n\n\n\n
Force at redirect \u2014- Time (sec) \u2014- \u2022\u2022\u2022\u2022Ohm 2 passive \u2022\u2022\u2022\u2022Ohm 2 dynamic<\/strong><\/p>\n\n\n\n
![\"Kraft-Zeit-Diagramm](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Gewichtsausgleich-beim-Klettern_kraefte-1024x510.jpg\")
Fig. 11<\/strong> Force\u2013time diagram of a fall event for active and passive belaying with the Edelrid Ohm 2.<\/figcaption><\/figure>\n\n\n\n Angle Dependence<\/h2>\n\n\n\n
In order to avoid resistance when pulling up rope to clip while lead climbing, the design of the devices allows the rope to run through with low friction when in the resting position. For activation, tension in the rope on the belayer\u2019s side as well as a bend in the rope path are required. Only the resulting vector force then activates the device.<\/p>\n\n\n\n
All user manuals (with the exception of the Bauer devices, where this is not necessary) state that the belayer should maintain a distance of at least one metre from the clipped device\u2014not just from the wall (this is important if the first quickdraw is in an overhang). In the event of a fall, however, the belayer is pulled upwards, which reduces the angle and can therefore also lead to activation (albeit slightly later). It can become critical if, due to an overhang, the belayer can swing underneath the device or the first quickdraw.<\/p>\n\n\n\n
![\"Illustration\"](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb12_Winkelabhaengigkeit-416x1024.jpg\")
Fig. 12 Particular caution is required when the first bolt is in an overhang. If the belayer is pulled towards the wall\u2014either by the pulling force during a fall or by the weight of the climber when weighting the rope\u2014the brake assistant may not engage, as a sufficient angle between the rope entering and exiting the device is not established. Illustration: Georg Sojer<\/figcaption><\/figure>\n\n\n\n At an angle of 180\u00b0 between the rope entering and exiting the device, the brake assistants do not activate, or do so very unreliably\u2014this was confirmed through fall tests. The Zaed only develops its full braking effect within a small angle range: between 145\u00b0 and 165\u00b0 full braking effect, below 145\u00b0 reduced braking effect, below 125\u00b0 no braking effect. The user manual states that the device may only be used up to a maximum overhang angle of 55\u00b0.<\/p>\n\n\n\n
If, on the other hand, a route starts on a slab, it may become difficult to lower the climber at all, as with a larger angle (>180\u00b0) the compensation value increases. Not all possible scenarios have yet been examined in detail\u2014therefore, careful and situational awareness while using the devices is important, especially when climbing outdoors. Among the open questions are what happens when the angle changes because the belayer is positioned further away from the wall, or when the route starts diagonally or with a traverse.<\/p>\n\n\n\n
Additional Practical Factors<\/h3>\n\n\n\n
In principle, when climbing with brake assistants, all the factors that generally influence belaying and weight differences within a climbing pair must be taken into account. This forms the basis for assessing whether the use of a brake assistant is appropriate and advisable in a given situation.<\/p>\n\n\n\n
For example, on a rock route with a zigzag rope path that generates additional rope friction, it may be the case that a brake assistant is not necessary, leads to excessively hard falls, or even makes it impossible to lower the climber. This effect is further amplified by rope diameter, rope condition (worn, fuzzy), and high humidity.<\/p>\n\n\n\n
For instance, if there is a weight difference of 15 kg between climber and belayer in a crag setting, combined with a non-linear rope path and an old, thick rope, the use of a brake assistant is not necessarily advisable.<\/p>\n\n\n\n
{{Lukas Fritz, 37, is a geographer, sport climbing instructor and mountain guide, and has been a member of the DAV Safety Research team since 2021. Through his work, he aims to help make falls\u2014particularly in indoor climbing\u2014more comfortable and safer for everyone involved. }}*<\/p>\n\n\n\n
Handling & Function<\/h2>\n\n\n\n
The pure compensation values are one thing\u2014but how easy are the devices to handle, and what pitfalls and particularities need to be considered in their use?<\/p>\n\n\n\n
Installation \/ One-handed operation<\/h3>\n\n\n\n
If you do not want to clip and unclip the device every time (for example when climbing the same line multiple times), the rope should be easy to insert one-handed. One-handed operation is most convenient with the Mammut Assist, followed by the Ohm. With all other devices, one-handed insertion is difficult\u2014sometimes even impossible\u2014and requires a fair amount of practice.<\/p>\n\n\n\n
The new version of the Bauer Espressi uses a bolt with a push-button as a closure. This simplifies handling, although inserting the rope can still feel somewhat fiddly\u2014if you are not careful, the rope can also be inserted in a pinched position. The Zaed, which also uses a bolt with a push-button, is relatively easy to operate. The Ohm has a push-button that is easy to use. The Assist can be opened easily using a sliding button; a positive feature is that the markings for correct rope insertion are visible in both the open and closed positions.<\/p>\n\n\n\n
Incorrect rope insertion<\/h3>\n\n\n\n
If the rope is inserted incorrectly, the devices\u2014depending on their design\u2014either provide no compensating effect (Zaed, Ohmega and Assist), little compensating effect (Ohm), or full compensating effect (Bauer devices Espressi & Zorro). In addition, it is not always immediately obvious to the climber or belayer whether the rope has been inserted incorrectly. Therefore, correct insertion should be included in the partner check.<\/p>\n\n\n\n
Deactivating the Device<\/h3>\n\n\n\n
One drawback: if you want to work a section, the activation travel of the device must be taken into account. In order for the device to fully engage, the belayer must, after taking in the rope and blocking off, give approximately 30 to 50 centimetres of slack\u2014i.e. move slightly towards the wall. This causes the climber to slightly drop back down each time.<\/p>\n\n\n\n
To deactivate the device, the same principle applies for all models: briefly shake the rope, and the device deactivates and swings back down into its initial position.<\/p>\n\n\n\n
Rope movement while climbing \/ unintended activation<\/h3>\n\n\n\n
It would be undesirable if the device were to activate when the climber pulls rope quickly in order to clip, thereby creating resistance. This issue has been observed in the past with slot-based devices such as the Ohm. With the newer version (the swivel in the Ohm 2), this occurs less frequently, but it is still possible.<\/p>\n\n\n\n
Devices that rely on a wrap angle allow the rope to run more freely, although the Bauer devices produce slightly more friction than a carabiner in all positions due to the rope path. The mounted rope pulley of the Ohmega creates less resistance than a quickdraw. The Assist is also hardly activated when pulling up rope. Note: as soon as the belayer applies even a small amount of tension to the rope, all devices will activate.<\/p>\n\n\n\n
![\"rope](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb13_Seilschlaufe-1024x683.jpg\")
Fig. 13 When the rope is inserted incorrectly in the Zaed, a loop forms in the rope during climbing. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n Lowering<\/h3>\n\n\n\n
Caution is required when lowering. In order for the device to fully engage and thus activate, it can help for the climber to commit their weight dynamically onto the rope. If the climber weights the rope too cautiously, it may happen that the belayer is slowly pulled towards the wall underneath the device and the brake assistant does not activate.<\/p>\n\n\n\n
Especially in overhangs, it can be difficult to re-establish the angle required to activate the device\u2014for example by pushing away from the wall. Using measurements of force over time acting on the belayer, we examined the lowering process in more detail. When lowering with the Ohm, more irregular and higher loads were observed, which indicates that smooth, jerk-free lowering is somewhat more difficult to achieve with this device.<\/p>\n\n\n\n
As expected, the smallest and most consistent force variations\u2014similar to lowering through a quickdraw at intermediate protection\u2014were observed with the Zaed (level 1), which also has the lowest braking effect.<\/p>\n\n\n\n
![\"last](\"https:\/\/assets.bergundsteigen.com\/2025\/09\/bergundsteigen-132_Bremsassistenten_Abb14_GebremsteLetzteMeter-938x1024.jpg\")
Fig. 14 If the last quickdraw is reached with the brake assistant still clipped in, lowering can continue in a controlled manner by clipping the carabiner of the brake assistant into the belay loop. Caution is required in overhangs or on uneven ground outdoors. Photo: Janotte, Berker, Fritz<\/figcaption><\/figure>\n\n\n\n Route Cleaning<\/h3>\n\n\n\n
The manufacturers\u2019 user manuals (with the exception of the Zaed) provide guidance on recommended procedures for cleaning a route. In order to remove the brake assistant after climbing, the following options are available:<\/p>\n\n\n\n
- \n
- Stop while lowering and clip in at the first point of protection. Remove the brake assistant, take in slack, and continue lowering. However, caution is required: the belayer may be \u201csurprised\u201d by the sudden increase in weight. For the final part of the lowering, the weight difference is no longer compensated. This method is not recommended in the case of large weight differences.<\/li>\n\n\n\n
- After lowering completely, climb back up from the ground to retrieve the device. If the situation allows this to be done safely (e.g. low first point of protection), it is best to downclimb again. If not, it makes sense for the lighter person to retrieve the device on top rope (tie in again and perform a partner check).<\/li>\n\n\n\n
- Clip in at the first bolt (or a nearby second bolt), remove the device from the bolt, and clip it to the belay loop. Weight compensation then continues to function. However, caution is required: lower carefully for the final few centimetres. The climber and belayer will be pulled towards each other\u2014if the route is not vertical, there is a risk of pendulum swings and impacts with ledges.<\/li>\n<\/ul>\n\n\n\n
*{{Marina Krabatsch completed her Master\u2019s thesis at the Chair of Biomechanics at the University of Bayreuth on the topic of \u201cComparison and quantification of the functionality of friction-enhancing devices for weight compensation in sport climbing\u201d and carried out the experiments in collaboration with DAV Safety Research.}}*<\/p>\n\n\n\n
\nSummary<\/h2>\n\n\n\n
Brake assistants can significantly facilitate belaying heavier climbing partners and increase safety. The determined compensation values provide an objective comparison of the braking performance of the different devices. However, these values are not fixed\u2014rope diameter, rope condition, route geometry, and even humidity all influence braking performance and should always be taken into account during use.<\/p>\n\n\n\n
The greatest influence, however, lies with the belayer. Good belaying is demanding, and especially lighter belayers who are not used to dynamic belaying should consciously adapt their belaying technique when using brake assistants, seek feedback, and practise.<\/p>\n\n\n\n
The primary purpose of brake assistants is to make a heavier climber \u201ceffectively lighter\u201d. Looking beyond this, the devices could also be used for advanced belaying techniques involving very fine control of the brake strand. By reducing the effective load of the climber, brake assistants can make it possible\u2014under suitable conditions\u2014to apply such precise belaying techniques.<\/a><\/p>\n<\/div><\/div>\n\n\n\n
- DAV article: Securing while climbing<\/a> in German<\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n