Bos forks and shocks brand new!
- Thread starter nicho
- Start date
Here it is summed up by dave and s. :
BOS is a specialist suspension tuning company run by Olivier Bossard. Started out by making forks and shocks for Nicolas Vouilloz (10x DH world champion) and they now also do the suspension work for Mitsubishi's WRC cars. They've been around longer than pretty well everyone else in the MTB suspension tuning field and always worked with the guys at the pointy end of the field (eg the old Sunn team). They currently make rear shocks (as seen on Daver's bike) and fork cartridges (for Boxxers, Foxes and possibly also 888s, not sure on that though) and are about to release their own fork. In other words - expensive stuff that is well and truly expected to deliver the goods... time will tell whether it does or not!
AFAIK (and S. is going to know more), the BOS runs much more dampening than a standard shock (for argument's sake, a DHX). I was lucky enough to replace the stock DHX 5 coil at Thredbo with the BOS shock, so I could ride the same track to see what the changes were. Basically, the bike is a lot more stable under cornering and braking- with the DHX I've found that the bike tends to bounce in the rougher sections, whereas the BOS seems to stick to the ground more. This was especially noticeable in the rougher, tighter sections (Bunnywalk). Ultimately, it's easier to hold speed in the rougher sections, because the bike is more stable. In the big bumps/drops (not that there's that many at Thredbo), the shock feels no different to a DHX. For jumping, IMO there's a big improvement with the BOS- while the rebound is slower, you can still get the bike off the ground easily, and when you land, the bike feels more balanced than before.
The downsides (it's not all that great) is that the BOS shock moves your weight much further forwards, especially in rough sections. I found that with Boxxers I ended up running 2 more clicks of compression to try and hold the forks up more, but this made the bike feel a bit harsher at the front. This is why BOS recommend a fork tune to match the rear.
On top of that, the low speed compression does sweet FA for pedaling, and the bike moves around a lot more under pedaling. Not that it's that bad for a DH bike, but it makes the bike feel more cumbersome in some sections.
Fabien pedemanaud / michael pascal i think and... a fresh one from aussie through Rouler Imports Dylan Prohm!
Yeah man for sure. getting promotional shocks next week and getting the first few forks in April!MY Gasket
man those forks just look da bomb!!
nice one nicho, keep us upto date on these bad boys
S. on Farkin is hooked to write up a massive review (that only him has the secret) once we have the kits.
yes it is a car strut!
Thea beauty about bos is that they also offer the alternative of running upgrade cartridges for boxxer, fox 40 and 888 and their complimentary rally developped bos oil!
Nicho
P.S. more to come soon.
jeremy_2640
Likes Dirt
Has anyone got any indications of cost??? For forks and the shock.....? I dare say it would be quite expensive...
scblack
Leucocholic
Guys guys,
the forks you are seeing are still being refined for a release in April.
they have a targeted weight of sub 3kg but no more precision as of yet!
and retail hasn t been set either.
Soon.
We are expecting 3 sets in April and you will see our sponsored riders riding the first sex toys (STOY) shock by mid march.
Nicho
the forks you are seeing are still being refined for a release in April.
they have a targeted weight of sub 3kg but no more precision as of yet!
and retail hasn t been set either.
Soon.
We are expecting 3 sets in April and you will see our sponsored riders riding the first sex toys (STOY) shock by mid march.
Nicho
Last edited:
stringbean
Likes Bikes and Dirt
sell your first born child
Dirt Devil
Likes Bikes and Dirt
Got a rough ballpark price for these?
My French is terrible but the website seems to say about 600 Euros ~$1000 AUD. Close?
Incontinent
Crusty Juggler
Doubt it the upgrade kit for the boxxers is 480 euros. (equates to $700-750 Au)
Look above, Nicho has stated that price for the forks hasn't been set yet and for that matter, first release run of the forks isn't expected until late April. nicho has also stated that they are looking at a target price range somewhere between Boxxer WC and Fox 40's.
Dirt Devil
Likes Bikes and Dirt
Cheers, but I'm asking about the cartridge upgrade kit which, from his post, sounds like it's already available.
sikpuppyonglory
Likes Dirt
very purdy
now that should win bike of the month, hands down, too bad it's overseas.
frikken nice.
now that should win bike of the month, hands down, too bad it's overseas.
frikken nice.
top_dog
Likes Dirt
$750 for the Boxxer. I've got one and it is awesome.
top_dog
Likes Dirt
Fabien Pedemanaud, Oscar Saiz, Mickael Pascal, Karim Amour and Nico but he isn't doing world cups AFAIK.
sikpuppyonglory
Likes Dirt
that's right top dog, show us another photo that is truely deserving of a BOTM nomination.
very nice indeed
very nice indeed
No Skid Marks
Blue Mountain Bikes Brooklyn/Lahar/Kowa/PO1NT Raci
Translated for your reading pleasure.contains literary abuse that may be sensitive to some viewers
Very waited new fork BOS of descent, succeeds the mythical reversed fork factory of V Process of Nicolas Vouilloz, whose last official appartition goes up with more than five years to the hands of the multiple champion of the world - and new test pilot bos!
In five years, much from water passed under the bridges of Toulouse, and we learned also much, in the various disciplines in which we invest ourselves, on the most level. If our experiment of the bicycle were initially used for the cars during the first years of existence of BOS, today, it is the official programs car, on which we are implied (WRC, rally raid), who return the similar one with the VTT!
Pressurized fork, Idylle Pro, since it is his name, is dissociated with the first glance gràce with its separate bottle. It indeed uses the technology developed by BOS as regards shock absorbers, and the similarity of aspect with famous shock absorber WRC machines Mitsubishi is obvious.
Like the shock absorbers of high performances realized by BOS, Idylle pro presents a hydraulic thrust of adjustable race end in length.
It is also noted that the block of adjustment of compression, located on the piggy back, is exactly the same one as that of the Stoy shock absorber... A sign which does not let plane any doubt about the fact that both make a particularly homogeneous unit.
Idylle Pro is adjustable in slow and fast compression, and relaxation.
The version that you discover here is a preproduction, very near to the final model, which should be available in a few weeks. By then, one works hard at BOS to polish the last details, with the contribution not only active but enthusiastic of Fabien Pedemanaud and Nicolas Vouilloz, which will have had the chance to make him carry out its first mêtres in DH!
To follow in the news! !
FAQ Idylle Pro
Why isn't it reversed?
Many awaited a fork reversed on behalf of BOS, whose image remained related to the fork machines V Process of Nicolas Vouilloz. To tell the truth, we much - not hesitated but thought of this subject! If only marketing had carried it, we would certainly have leaned side UPSD without hesitating... But we wanted above all to leave a product judicious, adapted to the context of the DH of today, and accessible for the pilots amateurs.
Reversed fork BOS exists... in drawing. But its realization entrainait constraints which appeared to us too much penalizing for the users. Indeed, to arrive to a satisfactory rigidity, it had been essential to manufacture a specific hub. With what that involves for the pilots: assembly of specific wheels, incompatibility with the current standards, and obvious overcost. With final, the reversed fork would have proven too much expensive! And we did not have the claim, for our arrival on the market of fork DH, of all chambouler.
Conversely, the conventional fork (when with its orientation), enabled us to respect the standards in force, for the comfort of our customers, but also to carry out a very powerful fork at a reasonable price.
Pressurized, why make?
In the motor bike, the most powerful forks are all pressurized. In particular in motocross (bottles intern), but also in Motor bike GP, where the bottles are very visible. We carried it out besides ya three years a kit of fork Moto GP, allowing to pressurize the conventional forks, with very beautiful results with the key. The first advantage of the pressurized fork lies in the fact that it functions like a shock absorber. Without going into the too technical details: hydraulics is at the same time more constant and more reactive. Moreover, one separates in fact the function rolling (damping) of the function of guidance, ensured by the same hydraulic fluid on the conventional forks. Idylle Pro thus calls upon two types of different oils: one for the friction, or the mechanical operation of the fork, the other for hydraulics it even. Not only, one thus uses the same block of adjustment of compression as on the shock absorber Stoy postpones, but also same oil. One guesses easily at which point the homogeneity of the unit is some increased.
shock - Successor of the DH07, Stoy is the new shock absorber of descent BOS. Still more succeeded than its predecessor, it evolves/moves in particular in design, with a new head piggy-back, and a shorter bottle. The whole of the block of adjustment of compression is completely new besides. Lastly, Stoy receives rings of assembly on needle bearing, a luxury hitherto a41dernier c-b1,e,10 c-b26 ce c-b16 c-b43,bn,84 reserved for the only shock absorbers "machines" of Nicolas Vouilloz. Advantages of the sytème: a catch of reduced type font to nothing, and an incomparable lifespan with the usual spacers.
Like all the shock absorbers BOS, Stoy is entirely dismountable and adjustable at will. The basic setting with which it is delivered is developed according to the bicycle for which it is intended, and it is always equipped with a spring corresponding to the weight indicated by the pilot.
Available for the majority of the bicycles of descent of the market, in the usual standard lengths, it can also be delivered in distances between centres and races except standard, on request.
Caratéristiques:
Hydraulic shock absorber monotube with valves type 3 ways
Adjustments; slow compression/fast compression/relaxation
Entirely dismountable and reconditionnable
Principal Setting "to measure"
Head, case guide, cylinder, nut of preload and foot out of aluminium
Stem ø 12 mm
Kit of assembly on needle bearings
Very waited new fork BOS of descent, succeeds the mythical reversed fork factory of V Process of Nicolas Vouilloz, whose last official appartition goes up with more than five years to the hands of the multiple champion of the world - and new test pilot bos!
In five years, much from water passed under the bridges of Toulouse, and we learned also much, in the various disciplines in which we invest ourselves, on the most level. If our experiment of the bicycle were initially used for the cars during the first years of existence of BOS, today, it is the official programs car, on which we are implied (WRC, rally raid), who return the similar one with the VTT!
Pressurized fork, Idylle Pro, since it is his name, is dissociated with the first glance gràce with its separate bottle. It indeed uses the technology developed by BOS as regards shock absorbers, and the similarity of aspect with famous shock absorber WRC machines Mitsubishi is obvious.
Like the shock absorbers of high performances realized by BOS, Idylle pro presents a hydraulic thrust of adjustable race end in length.
It is also noted that the block of adjustment of compression, located on the piggy back, is exactly the same one as that of the Stoy shock absorber... A sign which does not let plane any doubt about the fact that both make a particularly homogeneous unit.
Idylle Pro is adjustable in slow and fast compression, and relaxation.
The version that you discover here is a preproduction, very near to the final model, which should be available in a few weeks. By then, one works hard at BOS to polish the last details, with the contribution not only active but enthusiastic of Fabien Pedemanaud and Nicolas Vouilloz, which will have had the chance to make him carry out its first mêtres in DH!
To follow in the news! !
FAQ Idylle Pro
Why isn't it reversed?
Many awaited a fork reversed on behalf of BOS, whose image remained related to the fork machines V Process of Nicolas Vouilloz. To tell the truth, we much - not hesitated but thought of this subject! If only marketing had carried it, we would certainly have leaned side UPSD without hesitating... But we wanted above all to leave a product judicious, adapted to the context of the DH of today, and accessible for the pilots amateurs.
Reversed fork BOS exists... in drawing. But its realization entrainait constraints which appeared to us too much penalizing for the users. Indeed, to arrive to a satisfactory rigidity, it had been essential to manufacture a specific hub. With what that involves for the pilots: assembly of specific wheels, incompatibility with the current standards, and obvious overcost. With final, the reversed fork would have proven too much expensive! And we did not have the claim, for our arrival on the market of fork DH, of all chambouler.
Conversely, the conventional fork (when with its orientation), enabled us to respect the standards in force, for the comfort of our customers, but also to carry out a very powerful fork at a reasonable price.
Pressurized, why make?
In the motor bike, the most powerful forks are all pressurized. In particular in motocross (bottles intern), but also in Motor bike GP, where the bottles are very visible. We carried it out besides ya three years a kit of fork Moto GP, allowing to pressurize the conventional forks, with very beautiful results with the key. The first advantage of the pressurized fork lies in the fact that it functions like a shock absorber. Without going into the too technical details: hydraulics is at the same time more constant and more reactive. Moreover, one separates in fact the function rolling (damping) of the function of guidance, ensured by the same hydraulic fluid on the conventional forks. Idylle Pro thus calls upon two types of different oils: one for the friction, or the mechanical operation of the fork, the other for hydraulics it even. Not only, one thus uses the same block of adjustment of compression as on the shock absorber Stoy postpones, but also same oil. One guesses easily at which point the homogeneity of the unit is some increased.
shock - Successor of the DH07, Stoy is the new shock absorber of descent BOS. Still more succeeded than its predecessor, it evolves/moves in particular in design, with a new head piggy-back, and a shorter bottle. The whole of the block of adjustment of compression is completely new besides. Lastly, Stoy receives rings of assembly on needle bearing, a luxury hitherto a41dernier c-b1,e,10 c-b26 ce c-b16 c-b43,bn,84 reserved for the only shock absorbers "machines" of Nicolas Vouilloz. Advantages of the sytème: a catch of reduced type font to nothing, and an incomparable lifespan with the usual spacers.
Like all the shock absorbers BOS, Stoy is entirely dismountable and adjustable at will. The basic setting with which it is delivered is developed according to the bicycle for which it is intended, and it is always equipped with a spring corresponding to the weight indicated by the pilot.
Available for the majority of the bicycles of descent of the market, in the usual standard lengths, it can also be delivered in distances between centres and races except standard, on request.
Caratéristiques:
Hydraulic shock absorber monotube with valves type 3 ways
Adjustments; slow compression/fast compression/relaxation
Entirely dismountable and reconditionnable
Principal Setting "to measure"
Head, case guide, cylinder, nut of preload and foot out of aluminium
Stem ø 12 mm
Kit of assembly on needle bearings
top_dog
Likes Dirt
My BOS Review
Here is my fairly in depth review of both the BOS DH07 and the BOS Boxxer Cartridge. Hopefully it'll help people understand what BOS is all about.
Note: While I am sponsored by BOS Engineering/Rouler I did not make anything up or ignore any negatives.
BOS Engineering Suspensions
BOS DH07
Firstly, (and probably fore mostly) a BOS shock is ordered for you and then built to order for your weight, your bike and its linkage design, your riding style and whether you ride clips or flats. As well as the custom valving mentioned above, the shock comes with the correct spring for your bike, as well as the correct hardware. BOS tout attention to detail throughout their website and they are absolutely correct. The hardware for instance has o-rings between the shock and the alloy spacers, to allow for some flex in the frame without bending the shaft. These o-rings also keep dirt out of your shock eyelets thus prolonging their life.
When you unwrap your new shock will notice how long the reservoir is, in a 9x3 shock it is as long as the shock body. There is also a silver sticker with the code for your valving, don’t lose this, as BOS can look it up on their system to see what to change if you want to tweak your shims further.
Installing the shock was the same as any other, so it will either be an easy job or a massive pain in the neck depending on your frame.
Once you’ve installed the shock, I would advise reading the manual (in dodgy Frenglish), especially the part where it specifies where you should put your adjusters. If you follow the instructions you will find you’ll have an amazing shock, simply light and day compared to my DHX5.0.
When you first sit on your bike you will immediately notice how soft it feels, don’t be surprised to find yourself with 50%+ sag. But that said it gets there quite slowly. This shock has huge amounts of low speed compression damping, bucket loads of it. It feels very similar to a motor cross bike when you sit on it, but not as wallowy. You can pretty well bottom the bike out by bouncing up and down on the seat slowly but forcefully, but push the rear of the bike into the ground as hard as you can or do a bunny hop and smack the landing and you’ll find it almost harsh. I was perhaps a little under whelmed by the car park test. The benefit of all this LSC is that the bike will not ‘pay out’ when it doesn’t have to, in bermed corners and g-outs for instance. Then you’ll hit a jump…
My DH07 came with a 300lb spring, a full 100lb less than what my DHX had. Incidentally I turned both of my shock bolts into bananas the weekend before I got my BOS through heavy bottoming of the DHX. To say I was sceptical about the BOS’ 300lb spring was an understatement (especially with the price of my Orange’s stainless shock bolts). So I started gingerly at first but then realized that this shock really is something special. When you land a drop (with a transition) the bike will compress, but not a lot. It sort of only goes back to the neutral position (50%) and no more. This may sound stupid but its definitely not. It feels like the bike doesn’t waste its time compressing when it doesn’t have to. When you hit something truly worth of compressing it will; a large jump to flat, that used to absolutely murder the bump stop of my DHX, caused nothing more than a slight thud of wheel touching ground. To say it was smooth is an understatement. The way I would describe this is that the shock has a brain inside it. When you leave the ground it says to itself, “We have left the ground, start the timer”, then while you are floating through the air it calculates how hard you are going to hit the ground, and provides the perfect amount of damping for the situation - every time.
Small bump compliance is of the order of the DHX, no huge improvements there, though traction is on another level, particularly when you get going fast. It seems the faster you go the broader the gap becomes between the two shocks. On one of my local tracks there is a fast, open, grassy section with some big sweeping corners with quite a few undulations and rocks in the grass. In this section the shock literally blew me away. Just so much grip, try as I might I couldn’t get the rear of the bike to break away. To get another opinion of the shocks prowess I handed my 224 over to a mate of mine, an elite rider who rides a V-10 and weighs a good 20kg more than me. He got to the bottom of the hill and said, “That’s the fastest I’ve ever been down there.” Quite a feat considering the time it takes to get used to a new bike. He also failed to bottom the shock despite his weight. Consequently my mate has placed an order for a BOS shock.
Rock gardens don’t feel much different on a DH07 compared to a DHX; perhaps rock gardens are an area Fox optimised the DHX for?
Negatives? Well there are a few. Firstly it makes Boxxer World Cups feel pretty second rate to be honest. Tip the bike into a gravelly off camber turn and you can be guaranteed the front end will let go first. Secondly because the shock doesn’t compress as often or as far as a DHX it makes you ride with your weight far forward. On steep tracks this overwhelms the Boxxers and they just feel underdamped and divey under brakes. To semi-rectify this problem I had to put an extra 20psi in the forks to hold them up more, with obvious tradeoffs in traction and bump absorption. Finally, the shock does seem to suffer from a degree of top out, even with the rebound damping set according to Bossard’s advice. This is not even slightly noticeable when you are riding, just if you pick the bike up by the seat, after compressing it 10mm or so. Obviously this is not something you do very often, so it’s not a drama. Importer, Nicho, tells me that it is normal for the shock to behave in this manner.
BOS Boxxer Cartridge (Bosser?)
After reading the BOS website I have this to share,
They’ve pretty much hit the nail on the head with that paragraph. I was able to reduce my fork’s spring pressure down to 100psi from the 135psi it needed to hold itself up with the stock MoCo damper. Traction in corners is once again on another level, compared to stock Boxxers, especially flat, high speed corners with rocks or roots or some other traction robber. As a whole the bike feels exceptionally stable, with very little pitching back and forth. The bike just does its own thing and leaves you to concentrate on picking the correct line and getting pedals in wherever you can.
Installation was very easy, easier than Rock Shox’s two-part damper. Simply pull all the Rock Shox gear out, put the cartridge into the lower, (be careful here, the manual warns that Rock Shox’s castings may not be of a high enough quality, and are not square, but mine was OK), do up the foot bolt, put the stanchion back in, fill with BOS oil (which comes with the kit and smells like bubble gum) and do up the top cap. Nice touches were the steel thread in the base of the otherwise aluminium cartridge and the hard anodised internals. This should keep your oil cleaner for longer. The existing Rock Shox rebound damper adjustment knob becomes the compression adjuster knob for the BOS damper and the rebound adjuster moves to the top of the leg. Once again BOS has provided baseline settings to get you started, and once again these are fantastic.
Integration
The shock and cartridge have almost the exact same action throughout their strokes, both only compress when they have to, both absorb landings they really shouldn’t and both offer unsurpassed traction. They nearly sound identical too.
All in all I’m extremely impressed by the BOS suspensions, both in their actions, and the quality of construction. Add to that the company’s undisputed heritage in the world of Downhill and Motorsport and you have a fantastic package that you will take with you from bike to bike.
This is where the BOS Suspenion really shines, fast corners, with plenty of rocks, slippery dust and undulations.
Here is my fairly in depth review of both the BOS DH07 and the BOS Boxxer Cartridge. Hopefully it'll help people understand what BOS is all about.
Note: While I am sponsored by BOS Engineering/Rouler I did not make anything up or ignore any negatives.
BOS Engineering Suspensions
BOS DH07
Firstly, (and probably fore mostly) a BOS shock is ordered for you and then built to order for your weight, your bike and its linkage design, your riding style and whether you ride clips or flats. As well as the custom valving mentioned above, the shock comes with the correct spring for your bike, as well as the correct hardware. BOS tout attention to detail throughout their website and they are absolutely correct. The hardware for instance has o-rings between the shock and the alloy spacers, to allow for some flex in the frame without bending the shaft. These o-rings also keep dirt out of your shock eyelets thus prolonging their life.
When you unwrap your new shock will notice how long the reservoir is, in a 9x3 shock it is as long as the shock body. There is also a silver sticker with the code for your valving, don’t lose this, as BOS can look it up on their system to see what to change if you want to tweak your shims further.
Installing the shock was the same as any other, so it will either be an easy job or a massive pain in the neck depending on your frame.
Once you’ve installed the shock, I would advise reading the manual (in dodgy Frenglish), especially the part where it specifies where you should put your adjusters. If you follow the instructions you will find you’ll have an amazing shock, simply light and day compared to my DHX5.0.
When you first sit on your bike you will immediately notice how soft it feels, don’t be surprised to find yourself with 50%+ sag. But that said it gets there quite slowly. This shock has huge amounts of low speed compression damping, bucket loads of it. It feels very similar to a motor cross bike when you sit on it, but not as wallowy. You can pretty well bottom the bike out by bouncing up and down on the seat slowly but forcefully, but push the rear of the bike into the ground as hard as you can or do a bunny hop and smack the landing and you’ll find it almost harsh. I was perhaps a little under whelmed by the car park test. The benefit of all this LSC is that the bike will not ‘pay out’ when it doesn’t have to, in bermed corners and g-outs for instance. Then you’ll hit a jump…
My DH07 came with a 300lb spring, a full 100lb less than what my DHX had. Incidentally I turned both of my shock bolts into bananas the weekend before I got my BOS through heavy bottoming of the DHX. To say I was sceptical about the BOS’ 300lb spring was an understatement (especially with the price of my Orange’s stainless shock bolts). So I started gingerly at first but then realized that this shock really is something special. When you land a drop (with a transition) the bike will compress, but not a lot. It sort of only goes back to the neutral position (50%) and no more. This may sound stupid but its definitely not. It feels like the bike doesn’t waste its time compressing when it doesn’t have to. When you hit something truly worth of compressing it will; a large jump to flat, that used to absolutely murder the bump stop of my DHX, caused nothing more than a slight thud of wheel touching ground. To say it was smooth is an understatement. The way I would describe this is that the shock has a brain inside it. When you leave the ground it says to itself, “We have left the ground, start the timer”, then while you are floating through the air it calculates how hard you are going to hit the ground, and provides the perfect amount of damping for the situation - every time.
Small bump compliance is of the order of the DHX, no huge improvements there, though traction is on another level, particularly when you get going fast. It seems the faster you go the broader the gap becomes between the two shocks. On one of my local tracks there is a fast, open, grassy section with some big sweeping corners with quite a few undulations and rocks in the grass. In this section the shock literally blew me away. Just so much grip, try as I might I couldn’t get the rear of the bike to break away. To get another opinion of the shocks prowess I handed my 224 over to a mate of mine, an elite rider who rides a V-10 and weighs a good 20kg more than me. He got to the bottom of the hill and said, “That’s the fastest I’ve ever been down there.” Quite a feat considering the time it takes to get used to a new bike. He also failed to bottom the shock despite his weight. Consequently my mate has placed an order for a BOS shock.
Rock gardens don’t feel much different on a DH07 compared to a DHX; perhaps rock gardens are an area Fox optimised the DHX for?
Negatives? Well there are a few. Firstly it makes Boxxer World Cups feel pretty second rate to be honest. Tip the bike into a gravelly off camber turn and you can be guaranteed the front end will let go first. Secondly because the shock doesn’t compress as often or as far as a DHX it makes you ride with your weight far forward. On steep tracks this overwhelms the Boxxers and they just feel underdamped and divey under brakes. To semi-rectify this problem I had to put an extra 20psi in the forks to hold them up more, with obvious tradeoffs in traction and bump absorption. Finally, the shock does seem to suffer from a degree of top out, even with the rebound damping set according to Bossard’s advice. This is not even slightly noticeable when you are riding, just if you pick the bike up by the seat, after compressing it 10mm or so. Obviously this is not something you do very often, so it’s not a drama. Importer, Nicho, tells me that it is normal for the shock to behave in this manner.
BOS Boxxer Cartridge (Bosser?)
After reading the BOS website I have this to share,
“The most noticeable difference is the damping. When you brake, it doesn’t dive as much. It does go down (which is necessary), but not as far and it’s more controlled. It’s the same on big compressions, the fork doesn’t sink down as much or spike. It’s the relationship between spring and damping … one is useless without the other!”
They’ve pretty much hit the nail on the head with that paragraph. I was able to reduce my fork’s spring pressure down to 100psi from the 135psi it needed to hold itself up with the stock MoCo damper. Traction in corners is once again on another level, compared to stock Boxxers, especially flat, high speed corners with rocks or roots or some other traction robber. As a whole the bike feels exceptionally stable, with very little pitching back and forth. The bike just does its own thing and leaves you to concentrate on picking the correct line and getting pedals in wherever you can.
Installation was very easy, easier than Rock Shox’s two-part damper. Simply pull all the Rock Shox gear out, put the cartridge into the lower, (be careful here, the manual warns that Rock Shox’s castings may not be of a high enough quality, and are not square, but mine was OK), do up the foot bolt, put the stanchion back in, fill with BOS oil (which comes with the kit and smells like bubble gum) and do up the top cap. Nice touches were the steel thread in the base of the otherwise aluminium cartridge and the hard anodised internals. This should keep your oil cleaner for longer. The existing Rock Shox rebound damper adjustment knob becomes the compression adjuster knob for the BOS damper and the rebound adjuster moves to the top of the leg. Once again BOS has provided baseline settings to get you started, and once again these are fantastic.
Integration
The shock and cartridge have almost the exact same action throughout their strokes, both only compress when they have to, both absorb landings they really shouldn’t and both offer unsurpassed traction. They nearly sound identical too.
All in all I’m extremely impressed by the BOS suspensions, both in their actions, and the quality of construction. Add to that the company’s undisputed heritage in the world of Downhill and Motorsport and you have a fantastic package that you will take with you from bike to bike.
This is where the BOS Suspenion really shines, fast corners, with plenty of rocks, slippery dust and undulations.