Technology

Optional Coil Conversion Kits

Hybrid Coil/Air Open Bath Cartridge Damper System

Hybrid coil option requires our open bath cartridge damper system as a starting point.


Equal force system Technology
(EFS)

Add option here
Hybrid Coil/Air system


Are you having trouble setting your sag on your air fork and not getting full travel?
Are you forced to run 30% or more to get the fork to feel less harsh and its packing up on descents?


Hybrid coil/air cartridge damper system

This is the key to a plusher more coil like feel because
the spring rate is not over sized compared to coil only MTB coil forks.

The reason you have to play with spring rates to get the best compromise is the reason you need ramp up through the
entire stroke, ramp up allows you to run much softer spring creating a plusher feel and
increased bottoming protection. In other words the lack of ramp up forces you to an over sprung system.

Think of the fork as creating 3 almost equal separate forces to create a properly un compromised suspension.
1.damping force, 2. spring to support your weight at proper sag and preload, and 3. ramping to increase the spring
rate as it gets deeper in the travel. If the damping is missing(compression open or all the way out) then it needs to be
over sprung or more ramp up is need to come up with a compromised solution. If the ramp
up is missing then the damping or spring needs to be over done for a compromised solution

This 3 part solution is what all forks have been using for 50 years, only MTB suspension tries to eliminate 1 of the 3
or 2 of the 3 parts for lighter weight and reduced cost.

How can we better make a coil fork even better!


A little history as to how this happened:

 The original or traditional coil forks were
designed for MX and the early MTB forks with a damper and spring in each
side, filled about 2/3’s with oil. This allowed the fork to create a coil
spring like feel for the first half of the travel. The air space above the oil
is compressed which produces an additional spring force in the last half of the
travel. This additional air spring effect does two things, it allows the
selected coil spring rate to be much softer because the air supplements and
increases the spring rate and the ramp up or progression can still be
controlled by the air volume compression by changing the oil height.

 MTB forks eliminated one damper to save
weight and reduce the cost to produce over the past 20 years and used a single
long over rated spring with no oil in the coil leg. This led to an air spring
version that emulates a coil to further reduce the  weight.
 This is essentially is where we are now with
your typical air spring system single damper front fork.

 Our hybrid coil conversion brings back the
ideal coil/air spring system without the added weight of traditional spring/oil
filled fork. The air side is still used to create the additional spring rate
and ramp rate at a much lower pressure. We use our open bath damper with a
lighter and shorter coil spring on top of it. The air spring side remains
unchanged and creates the additional spring rate. The air side now uses about
1/3-1/2 of the pressure that you currently used to create the additional
spring rate which can be adjusted to support your weight and ramp up desired.
 
 This hybrid system works in conjunction with
our open bath custom valved damper with our exclusive midvalve and high speed
blow off system (FvAT/HSB). Our damper creates a very supportive compression
system that prevents fork dive and still feels plush on small bumps. This
midvalve system and base valve will still blow off to prevent deep square edged
harshness without bottoming.


Typical Hybrid Coil/Air Spring Combined Forces

Flattens the belly(hammock) in the air spring system for more midstroke support.

Hybrid Coil/Air vs Tokens vs Oil Height Spring Forces

As you can see the tokens will change the progression thru the middle to end of stroke.
The air over oil height will change the end ramp up while leaving the midstroke more linear.
Flattens the belly(hammock) in the air spring system for more midstroke support.
Increasing the hybrid coil rate will lower the air pressure needed which will also further reduce the midstroke making the fork even more linear.

Optional Foam Sleeve
Foam rubber sleeve reduces air over oil ramp up(acts like an accumulator) and makes the fork feel more linear while reducing end stroke ramp up(similar to end stroke bumpers).

 

 

How our customer describes this system, "Motocross forks utilize a combo of coil and air (they use oil volume to adjust air pressure progression) because it tends to work the best. You get a fork that isn't initially too soft/ divey and a well supported mid stroke due to the coil and then you get the progression needed at the end to prevent harsh bottom outs. No doubt a hydraulic bottom out works as well but then you might lose some other benefits of a hybrid setup, mainly spreading the spring force between both legs so that they work in better harmony. With all the spring force in one leg of a mountain bike fork some have reported notably different amounts of travel being used by each fork leg due to the flex."

The hybrid coil kit supports about half the rider weight and the air spring makes up for the other half of the support needed. Now the air side can be used to fine tune the spring rate needed as well as adjust the ride height for different riding conditions, also the air ramp-up can be controlled with the traditional tokens or aftermarket ramp up adjustment devices. The advantage of the hybrid system is versatility, performance, weight, and cost savings. It simply drops on top of our open bath damper side, only adds about 180 grams(250 grams for 8 inch fork), it solves most of the air spring issues in the first half of the stroke, where the friction forces and small bump compliance are critical, more supportive, it fills in the midstroke wallow of the air spring and corrects the ride height with physical adjustable preload. When the fork gets deeper in the stroke the spring force is more dominant and the stiction and air spring concerns are not as noticeable, so the final spring force is not as sensitive as long as it is more linear and removal of the tokens is now possible with proper damping. The air spring can be set to very low pressures and as linear as possible where it is nearly negligible. Ride height and spring rate can be fine tuned with the air spring pressure which is very helpful when in between spring rates and allows for different riding conditions. The equal force system is a very important feature because now the fork compresses equally with about the same spring rate in both stanchions, a single spring system causes the unsprung side to compress ahead the spring side because of the flexibility of the crown and lowers, this causes stiction in the first half of the travel which is more of a contributor than the air spring stiction. The abs system that we sell as an option to our damper is not necessary because of the air hybrid ramp up is sufficient to prevent bottoming.

Download: Air Sprung vs Coil vs Hybrid Coil/Air Cartridge Systems

 

Hybrid Coil and Open Bath Damper System


Hydraulic ABS is not required for bottom-out protection but will improve deep square edged performance if used in lieu of air rampup.

Hybrid coil option requires our open bath cartridge damper system as a starting point.

Available for Fox 40 Float (203/190), Boxxer 38 (203/180), Boxxer Ultimate/Select (203/180)Boxxer World Cup(203/180), Fox 38 (150/160/170),Fox 36/Z1 Bomber(180,170,160/150/140), Zeb (150/160/170,180)
MRP, Pike 29er (2014-17) 150, Lyrik/Yari (160/150/140 limited to riders under 210lbs)

 

 

Single Crown Forks

Hybrid Coil/Air Option

Fox 36/Z1 Bomber(180/170/160/150/140)

Fox 38 (150/160/170,180)

Mezzer 37(160/170,180)

Zeb 38 (150/160/170/180)
call for 190mm limitations

MRP 160 mm limited to riders under 185 lbs

Lyrik/Yari (160) limited to riders under 185 lbs

Mezzer (160/170/180)

Download: Hybrid Coil Air Cartridge Installation and Set-up Manual beta(3 MB)

Watch(stream google)the Install Video(unedited sorry)

Watch small video file(387 MB)


Keep in mind the required spring rate for heavier riders can still be achieved
with a combination of the coil and air spring, but the hybrid affect will be lessened
(the coil like feel will be less as more air pressure is required to make up for the spring rate needed)

Fork

Choose rider weight.
Rider weight is without gear, we add 5-7 lbs for DH gear, 7-10 lbs for All-Mtn/Freeride.

Rider Weight

 

Fork Travel

Fork Travel

Hybrid coil option requires our open bath cartridge damper system as a starting point.

Price $299 single spring system

 

 

 

 

Dual Crown Forks

Fox 40 Float, Fox 49, Bomber 58*(203/190)
2010-2018 Boxxer (200)^
2019- Boxxer 35(180/190/200)^
2024- Boxxer 38(180/190/200)
Dorado 37(203)

^ maximum rider weight 240 lbs/ 185 lbs E-bikes

Download: Hybrid Coil Air Cartridge Installation and Set-up Manual beta(3 MB)

Watch the Fox 40 Mid Hybrid(older style) Install Video(unedited sorry)

Fork

Choose rider weight.
Rider weight is without gear, we add 5-7 lbs for DH gear, 7-10 lbs for All-Mtn/Freeride.

Rider Weight

Fork Travel

Fork Travel

Hybrid coil option requires our open bath cartridge damper system as a starting point.

Weight of Bomber 58/Fox 40 Hybrid Coil Cartridge System, adds 375 grams for 35 lb/in setup (190 lb rider).

Price $299 single spring system

 

Dual Dampers / Dual Coil Springs

Fox 40 Float, Fox 49, Bomber 58*(203/190)
Fox 36/Z1 Bomber(180/170/160/150)
Fox 38 (150/160/170,180)

2010-2018 Boxxer 35 (180/200)^
2019- Boxxer 35 (180/190/200)^
2024- Boxxer 38 (180/190/200)

Zeb 38, Domain 38 (150/160/170/180)
call for 190mm limitations

Call for Dorado Pro, Expert and Comp availability


^ maximum rider weight 240 lbs/ 185 lbs E-bikes

 

Dual damper/dual spring cartridges with HBO available for all models. $1899

Dual Damper dual spring system shown.
Hybrid cartridge system is just one damper and coil
used with stock air spring at about 1/3 the pressure.

Download: Coil Cartridge Installation and Set-up Manual beta(3 MB)

Watch the Fox 40 coil Install Video(unedited sorry)

Fork

Choose rider weight.
Rider weight is without gear, we add 5-7 lbs for DH gear, 7-10 lbs for All-Mtn/Freeride.

Rider Weight

Fork Travel

Fork Travel

Dual coil option requires our open bath cartridge dampers system as a starting point.

Includes Hydraulic Bottom Out(ABS,) dual coil springs and dual open bath dampers, custom valving and setup sheets.

Price $1899 dual spring system

 

 

 

techinfo@avalanchedownhillracing.com