There are no proper reviews about BOS Idylle RaRe Air anywhere, so how good is it really? There are plenty of Fox, Rockshox, Marzocchi... reviews, but no comparisons with BOS. I read somewhere that the small bump smoothness of the Idyle air is the same as in a coil fork and at the same time I hear that coil versions of every other manufacturer (40 Float, Boxxer WC) feel better than air versions. Are BOS forks really that good? I hear the 380 has the best beginning stroke plushness, is the Idylle comparable to that? Especially the new 37 FCV (i know it's a bit early to ask if anyone has ridden it yet). I know it's an expensive fork and hard to get customer support but just from a performance standpoint, is it really as good as some claim (compared to other 2014-2015 forks)? I know there are threads about this fork, but there's no straight comparison of this fork with others.
BOS Idylle vs others
- Thread starter sasky115
- Start date
Air forks can never move as freely as coil forks because they will always have the additional friction of the air seals to overcome. To say otherwise would be to ignore the laws of physics. Air springs that use a coil negative spring usually need 2 sealing lips minimum (one for each direction on air piston unless they use an o-ring, which seems to be inferior and not used these days), while those that use an air negative spring will need at least one additional seal to seal off the negative chamber.
The benefit to having an air negative spring is that the air spring as a whole will truly cater to different rider weights, while those with a negative coil spring reap the benefits of less sliding seals but need a different coil spring rate to suit different air pressures. Companies like DVO do offer some tunability in their negative coil spring with the preload adjust option (they call it OTT: off the top) which helps alleviate this issue but the point still stands.
The other issue is that most air springs suffer from non-linearity, often a harsh initial action to overcome air-preload effects followed by a digression in the spring curve (only on forks with air negative springs - an undesirable mid stroke diving effect) followed by progression in the spring curve near end of stroke. This is somewhat alleviated in forks like the new 36, Pike and Boxxer through use of larger negative chambers (to reduce mid-stroke digression and some early stroke harshness), and DVO by the use of the OTT (to decrease initial resistance; this actually works impressively well). In the end though these systems are always inferior to a coil spring due to reasons listed above. In my opinion DVO gets the closest to a coil spring feel by far, but their current DH fork is stupidly heavy and thus not really a contender for most people.
I've ridden a few RaRe forks now and personally I think they have noticeably more stiction than a coil fork, but it's acceptable/good for an air fork. I have not ridden the FCV but if you've understood everything I wrote then you'll see how it won't match a coil spring. On the other hand, different people have different requirements of their gear, so maybe it will work just fine for you as it will for many others I'm sure.
Ride them for yourself and see, otherwise hopefully this helps.
The benefit to having an air negative spring is that the air spring as a whole will truly cater to different rider weights, while those with a negative coil spring reap the benefits of less sliding seals but need a different coil spring rate to suit different air pressures. Companies like DVO do offer some tunability in their negative coil spring with the preload adjust option (they call it OTT: off the top) which helps alleviate this issue but the point still stands.
The other issue is that most air springs suffer from non-linearity, often a harsh initial action to overcome air-preload effects followed by a digression in the spring curve (only on forks with air negative springs - an undesirable mid stroke diving effect) followed by progression in the spring curve near end of stroke. This is somewhat alleviated in forks like the new 36, Pike and Boxxer through use of larger negative chambers (to reduce mid-stroke digression and some early stroke harshness), and DVO by the use of the OTT (to decrease initial resistance; this actually works impressively well). In the end though these systems are always inferior to a coil spring due to reasons listed above. In my opinion DVO gets the closest to a coil spring feel by far, but their current DH fork is stupidly heavy and thus not really a contender for most people.
I've ridden a few RaRe forks now and personally I think they have noticeably more stiction than a coil fork, but it's acceptable/good for an air fork. I have not ridden the FCV but if you've understood everything I wrote then you'll see how it won't match a coil spring. On the other hand, different people have different requirements of their gear, so maybe it will work just fine for you as it will for many others I'm sure.
Ride them for yourself and see, otherwise hopefully this helps.
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Thanks for the reply, I never tried an air DH fork before (only coil) and just had to ask. I really like to play with fork pressure on my trail bike to get it just right, that's why i like air (don't own a DH bike right now) and the air fork does indeed have more stiction than a coil boxxer for example. How does the Idylle compare to other forks in general (not just small bumps)? I hear it stays high in its travel and is in general very good, just how big is the difference compared to let's say a 40 Float or Boxxer?
For Dh, I'd go for rare coil. Because I use Deville on trail bike and it is nothing but amazing. Using coil, it will give consistent feeling on a couple of rides.
So long you know who to send stuffs for service and deal with extra eventual costs, you'll be happy.
If you're good rider and know exactly what you need for setting a fork, Fox 40 seems consistent choice for tunability and boxxer - price (at least in Europe, there Fox costs same as BOS air)
So long you know who to send stuffs for service and deal with extra eventual costs, you'll be happy.
If you're good rider and know exactly what you need for setting a fork, Fox 40 seems consistent choice for tunability and boxxer - price (at least in Europe, there Fox costs same as BOS air)
If you don't want worry and want get more value for fork, I'd pick marzocchi 380cr.
It may not be best, lightest but in overall it is hard to beat for the price.
It may not be best, lightest but in overall it is hard to beat for the price.
I've got a set of 2013 Idylle RaRe Airs and they're incredible. The small bump sensitivity is not as smooth as a Marz but the ones I've tried almost feel too soft. I'm running the LSC half in on the Idylles too and they're a lot more compliant and stiffer torsion ally than my old 2010 TF Tuned Boxxer teams and 2012 Boxxer WCs.
They are expensive (unless you find someone who's splitting a Tues WC like I did) but personally I think they're worth it. Finding a service centre for maintenance has historically been a problem but it's not something I worry about given that the sealing and quality of parts/oil is so good.
They are expensive (unless you find someone who's splitting a Tues WC like I did) but personally I think they're worth it. Finding a service centre for maintenance has historically been a problem but it's not something I worry about given that the sealing and quality of parts/oil is so good.
Bos is unbelievable, I purchased an idylle Rare Air and it blew me away. Something that i noticed with the bos over other AIR forks, is the lack of friction compared to lets say a boxxer WC or air 40. It rides like a coil, and compared to the coil idylle i had for a VERY short time before it i felt that they were close to identical. Mostly because the bos air neg spring balances out. Something that makes a HUGE difference. BOS also anodizes the internals so they glide super smooth. UDI is right that they physically cannot ride like the comparable coil fork, however, the additional attention to detal BOS does makes it something you cannot notice in practicality. Nobody that has ever ridden my bike on the parking lot or trail does not mention how much better it feels than their fork in terms of stiction. I may sound like a total fanboy, but it is really like cheating compared to the other stuff currently available. Their damping tune is just amazing, it really just smooths out the trail to a level that is almost hard to believe. 1 thing that may be worth noting, is that i felt the Axle to Crown was a bit short, compared to a 888 at least, I had to add a stem rise spacer to make it feel like my old 888 did. It may or may not be worth the price, but if you are looking for the BEST, it has to be BOS. (I just ordered a FCV and a Void for my new DH next year)
PS, I think that the Kirk is the best product Bos makes. (after i got my idylle i was so impressed that i went out and swapped all my suspension stuff over to bos and i feel that its the best move i have made. (aside from an almost 2 year service interval)
PS, I think that the Kirk is the best product Bos makes. (after i got my idylle i was so impressed that i went out and swapped all my suspension stuff over to bos and i feel that its the best move i have made. (aside from an almost 2 year service interval)
Also on a 2013 Idylle rare air.
That fork is really amazing. Rides high in it's travel, the hydraulic bottom out safes your life on death bringing g-outs and the overall sensitivity is astonishing.
I can definitely recommend their dh fork for sure!
The shocks are a little bit of another story though. If you don't like to ride atleast 30-35% of SAG you will have a little bit of problems to set the shock up properly regarding high speed shaft speeds.
That fork is really amazing. Rides high in it's travel, the hydraulic bottom out safes your life on death bringing g-outs and the overall sensitivity is astonishing.
I can definitely recommend their dh fork for sure!
The shocks are a little bit of another story though. If you don't like to ride atleast 30-35% of SAG you will have a little bit of problems to set the shock up properly regarding high speed shaft speeds.
a Kirk shock on your DH rig? this time, Canfield, right?
2 years service interval is not bad. Compare it to every second ride service on fox (literally)
I agree that BOS stufs are the best now........at least for a rider like me who hates to fiddle with settings. It transformed my ride literally at stock setting and i was thinking "thats Holy Grail I was searching for"
Re experienced riders, thats different story. Useful to read comments from guys like you with good skills!
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I want to mention service center. Mad Elks, located in Dublin, has been consistent so far! They even fixed faults on brand new product that came from France. Kudos to them!
BTW, dont send things directly to BOS or any service center with bad reputation!
BTW, dont send things directly to BOS or any service center with bad reputation!
I have ridden the majority of the top forks available today. The BOS RaRe was noticeably better than all of them. I wanted them not to be better (because of the French factor), but the simple fact (imo) is that they are.
Udi, in my experience, while air forks might always have more stiction than coil (if you compare those factors in isolation) - the BOS air forks have less than the coil of any of the other manufacturers that I've tried.
One issue that they might have at times, is that the bushings are quite loose from factory (assuming to combat said potential stiction). One friend of mine's Devilles were too loose and had to be sent back under warranty.
Of course it took ages as the French implied that the customer was at fault ... but we got there in the end.
Udi, in my experience, while air forks might always have more stiction than coil (if you compare those factors in isolation) - the BOS air forks have less than the coil of any of the other manufacturers that I've tried.
One issue that they might have at times, is that the bushings are quite loose from factory (assuming to combat said potential stiction). One friend of mine's Devilles were too loose and had to be sent back under warranty.
Of course it took ages as the French implied that the customer was at fault ... but we got there in the end.
Nah the kirk is on my enduro bike with a deville up front.
Right now i have a stoy on the rear whoch while being mega supple, really does not offer much more in performance.
Feels like a less sticky rc4 or elka, stoy is their "worst" product i think
Right now i have a stoy on the rear whoch while being mega supple, really does not offer much more in performance.
Feels like a less sticky rc4 or elka, stoy is their "worst" product i think
ah I see, how is Kirk and Deville, very similar to Idylle Rare in feeling?
I agree, the french factor is strong with this
Their tune is really specific and needs lots of SAG to work properly. Otherwise you most likely will have a shock which spikes and bucks a lot.
I have expirienced this both on my bike, eventhough riding with 30% SAG on my DH-bike. This spring I plan to test a CCDB on my bike to see if I can get more performance out of my frame.
This.
Their tune is really specific and needs lots of SAG to work properly. Otherwise you most likely will have a shock which spikes and bucks a lot.
I have expirienced this both on my bike, eventhough riding with 30% SAG on my DH-bike. This spring I plan to test a CCDB on my bike to see if I can get more performance out of my frame.
arent your a "sponsored" rider?
not by bos, bos is not even sold in the states. I ride for Canfield, which does offer bos, but only with their frames. (you will notice i did not even mention that)
The deville is similar for sure, the biggest thing i noticed over the pike was consistency, its a bit heavier, but also more burly feeling. The only think that I think makes it worth it is if you really plan on rallying the snot out of downhillish trails. It is super consistent and never gets caught by surprise like my pike would do. It always rides higher in the travel but thats sort of a general bos trait.
The kirk is unreal though! It hardly weighs anything and is so damn smooth. (I prefer the kirk to the stoy) Generally i am not as picky or maybe expect less out of a rear shock since you stand on it compared to holding it, but I have noticed the kirk being abnormally smooth compared to my ccdb air on more than one trail.
Worth noting, i have 300 psi in it and its still a bit on the soft side. So at least with the tune it has and my bike, it needs alot of air. (My weight before pack is 220 lbs)