If there is any area in which technology is putting all eggs in one basket in the mountain bike, this is undoubtedly that of suspensions. Terms such as SAG
Compression, High speed, pedaling platform .... etc have been introduced into our daily vocabulary of the overnight not without significant effort on the part of professionals and of course also the users, often are overwhelmed by this deluge of acronyms and technical terms in many cases, without adequate explanation from the professionals can not understand.
continually see how the brands are struggling in designing new suspension systems that more or less successfully manage to solve the problems or should I say the new requirements demand the modern mountain bike.
First of all, they should know a number of terms that will help us better understand the operation of the suspensions:
Balance suspensions:
Both front and rear suspension should also be made in accordance with the rider's weight, skill level, riding style, terrain .... etc
pilot regulations do not have to serve another.
SAG:
Whether a suspension fork, like a rear shock and spring regardless, oil or air compression element, the first adjustment you'll have to make is that of the SAG.
What is SAG? Well I must admit that after searching throughout the Internet, I have not found a translation of that word, although the verb "to sag" is synonymous with "to drop" which means jump.
But since giving a definition, is simply the path of a shock that has been precompressed in running order, with the rider on the bike. Has no units because it is a percentage of total shock travel.
SAG greatly influences the behavior of the suspension and is inversely proportional to the preload of the main camera, or what a Christian says, means that the higher preload SAG lower compression and vice versa.
Its setting depends on the type of driving you to give to your machine:
- Cross-country and competition: 12% of total shock travel.
- Free-ride or fall: 30% of total shock travel.
- For the rest of us: 20% of total shock travel.
These values \u200b\u200bare general and I fully recommend reading the instruction manual of your cushion, if you have not thrown in the trash.
His adjustment we will take you over 10 minutes and is recommended to do when purchasing your new bike, or changing shock / fork and control is necessary a few times a year.
Before starting to adjust, we must ensure that all regulations are zero, especially the pre-compression.
SAG adjustment on the fork:
To start you must know the total length of your forks. You have two methods, I Fiais of what I said the manufacturer: 80, 100, 130 or even 150 mm, or what you measure. For this second option, you must mount an electrician clamp fork tube, put in contact with the seal of the bottle and the fork until it stops. The bracket will be at the top of the tube and you can measure and which has been the actual travel up your forks, from the edge of the retainer to the bottom of the bracket.
Anotáis that measure and comeback to put the clamp on the bottom position, and now, better with the help of a friend to keep in balance on the bike, go up to her and you guys put into working. You lower the bike, carefully not to further compress fork. You measure the route and compare it with the total fork.
If the result is less than what you want to, you must reduce the pre-compression: in air forks, reducing the pressure of the main chamber, or removing brackets round the spring adjusting nut precompression. And vice versa.
with an example: Suppose you have a range of 100 mm maximum travel, and want to use for a Free-ride use of SAG (30%), then you will have to adjust the main chamber pressure so as to be 30 mm fork sunk when I go up to the bike.
the bike must be in running order, that means with the right clothes, the camelback filled to the back, the apple in the pocket of the jersey, tools and full water bottle on board ...
If you have a fork Adjustable travel Fox Talas or similar type, will need to adjust the SAG with the fork to maximum travel.
adjustment in the rear shock absorber SAG:
If the shock is air you will have to proceed like the front fork spring and if then you have probably problems accessing the piston rod and place it clamp. To do this it is best with the help of a friend, you measure the distance between the two axes damper fixing comparéis rest and the distance between those two points, but uploaded to the bike.
Author: OR BTT see link
Bobbing:
The bobbing or pedal-induced subsidence is the movement and the consequent loss of energy produced in the suspension when pedaling. This is one of the main problems that faced the double suspension in its infancy and the main argument of the "suspension" skeptical "
driving Stability:
Say is a collection of factors that control the bobbing, the subsidence caused by braking and ultimately the uncontrolled behavior of the suspensions when they are not properly regulated.
Spike:
is the feeling that occurs when a high velocity impact the shock can not compress fast enough to absorb the impact, size of the obstacle at the moment of contact.
Compression damping:
is the ability of the suspension of regular speed input shaft or bottles during the impact. Impacts can be adjusted to high and low speed. Damping
Rebound:
is the opposite of the previous one, in this case, regulating the output speed of the bottles-stem after impact. controls the speed at which the suspension (and wheel) returns to its original position after being compressed.
Once these basics, we can better understand the operation of any type of suspension.
could say that there are two forms of "cushion." Let's focus on this case at the rear suspensions so we refer to these as shock absorbers.
These two control systems are known as damping and Speed \u200b\u200bSensitive Ride Control Sensitive Position.
control sensitive compression damping rod speed at impact is the result of, as you might imagine, the speed with which the piston and rod penetrating oil due to the impact. When the speed is low, there is little compression damping, when the speed is high, the compression damping is high.
To achieve this, we use a series of flexible rings that let in more or less oil depending on the strength that oil has on them.
To illustrate this in an easier way, let the piston in the oil with a hole of a given diameter. At low speed, the oil can opposing freely through the hole in little or no resistance to the advancement of the piston. But at high speed, the hole would not be able to evacuate a sufficient amount of oil needed for the advancement of the piston, whereupon the force that opposes the advance would be too strong and the shock would not be able to absorb the impact. What you get with these washers is that at low speed the "hole" is small, creating a buffer of low speed compression, but that at higher piston speeds increased flow of oil makes these washers Flexen increasing the size of our "hole" allowing more oil to pass through the piston.
To test and design used throughout this a dynamometer to evaluate the suspension forces at different speeds. From here, you get graphics that represent the velocities in the axis "X" and the damping force of the "Y".
In this type of shock, a small change made in the thickness and / or quantity of washers can produce large changes in the graphs of suspension.
If for example we want to eliminate pedal-induced collapse by increasing the damping of low speed compression, often can not avoid this is reflected in an increase in high-compression damping by increasing the spike.
For control systems position sensitive damping, things work differently, the damping force depends only on a small percentage of the spindle speed at impact. The compression damping force depends on the position of piston travel.
have been different ways of trying to achieve, with varying degrees of success, such systems in the past, we will focus on the control system Element Curnutt/5th compression damping position sensitive.
In this system, the piston velocity plays a minor role in controlling the compression damping and the system can achieve high values low-speed damping (which allow us to eliminate the bobbing) without affecting the high-speed compression. That is, if we have 45 kg of damping force at 5cm / s, 75cm / s will also.
In this system, we can set a value of compressive strength from which the shock begins to run, which can eliminate the annoying bobbing increasing pedaling platform. In addition tb. can regulate the progressive compression damping, ie, we can make this increase but when the shock reaches the end of his tour which can be used to avoid such impacts in large caps.
Now let's imagine a camera slow what happens within a buffer in a high velocity impact such as a landing after a jump, a root, rock ... etc. As the wheel hits the obstacle is accelerated at high speed. For example, if we jump from 2.5 m level, our body would fall to about 750 cm / s on a bike with a gear ratio of 3:1 would-piston stem 250 cm / s in a very short time.
absorber damping in a speed-sensitive, early in the tour would notice most compression damping force as flexo washers but not let you pass up all the oil flow necessary and produces what is known as a spike of high speed. As we go on the tour, the spindle speed decreases and thus the compression damping will also fall which does not provide much protection against bumps.
Let us now what happens in this scenario but with a compression spring system sensitive to the position. When the wheel hits the obstacle and the rod is accelerated to such 250 cm / s, at the beginning of the journey offers little shock compression damping, allowing the wheel to move more freely. As we move into the run and the stem is decelerating, this system will increase the compression damping smoothly and gradually even at the end of the course. Thus, the shock decelerates us smoothly and progressively without feeling any sharp spike rate honoring the adage that the harder you give smoother response. Example
amortiguadror Fox Float RP3 regulation:
Rebound damping controls the rate of return of shock after being compressed. The proper rebound value is a matter of personal preference and varies depending on the weight of the rider's driving style and conditions to be riding. The rule of thumb is that the rebound as fast as possible without kicking back and be as strong to push the rider off the saddle. The rebound knob has nine clicks of adjustment.
For slower rebound, turn the red adjuster knob clockwise.
To speed up the rebound, turn the knob counterclockwise. ProPedal
ProPedal adjustment lever adjusts to three positions ProPedal function on the fly. ProPedal damping reduces the pitch of the suspension caused by pedaling. Three position adjustable lever:
1. LIGHT ProPedal
2. MIDDLE ProPedal
3. FULL ProPedal
(LEFT + = 3 / CENTER = 2 / RIGHT - = 1)
Use the different settings to tune the shock to different conditions and driving situations. For example, use
full ProPedal position to climb to the top of a mountain then go to the light
position for the descent. Each suspension has a different design, and each rider skill level, so that the optimal positions
vary from bike to bike and a rider to another.
To determine which position ProPedal is the best, ride about 25 km / h and observe the movement of
shock. Switch between positions and select the one that reduces suspension movement most effectively
at the same time it provides the desired amount of bump absorption. The adjustment can
change with different conditions and styles.
The "neutral zone" between the complete and ProPedal ProPedal light is simply a transition zone between the two
. However, FOX do not leave the lever in the "neutral zone", since it does not hold,
so you could accidentally move the entire position or the light if you are driving in tough conditions. Published
forocantabria by chupacabra. Nacho
Herráez
SL Comp Bike Technical Department
dptotecnico@bikecomp.com
91-5618646 Author's Note:
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