Bos Idylle Rare Service Manual
Mike, I'll thank you not to speak for my dyno testing, especially when you haven't seen the results yourself. The BOS has exceptionally fine and linear adjustments, but it also has a very limited adjustment range, and such high levels of HSC that it's no surprise that it's excessively harsh on a lot of frames and for a lot of riders. It certainly isn't what I'd call 'head and shoulders better performing than anything else'. It's great in many regards, but it isn't perfect, and more notably, it isn't well suited to all frames (even with the 'correct' tune).You should also be aware that Udi is both a BOS owner (in fact, it was his shock I dyno'd!) as well as being one of very few people who's ever seen actual dyno testing results of a Stoy.
Bos Idylle Rare Service Manual Download
Forks spare parts large choice at probike warranty settings maintenance bos idylle rare 2017 user manual spare parts large choice at probike spare parts large choice at probike. Whats people lookup in this blog. BOS idylle SC Air in Downhill. Posted: Jan 24, 2016 at 22:25 Quote: Hi mate I've been running the idylle sc air for two years and can't say enough good things about it.
I think you may be wasting your time trying to tell him how good his shock is. Vikingboy -My rider weight is fairly average at about 80kg with gear.You don't 'work with BOS' - you just get a preset tune for your frame (1 of 5 tunes back then) and they recommend settings and a spring to go with that - neither of which were correct in my experience. They do not take into consideration rider weight or style, only the frame's leverage ratio.If you think about it, combining that principle with a very narrow range of adjustment is flawed logic. But when it doesn't work for someone of average weight, it's just poor valving. Interestingly enough the problem would only surface hitting square edges at quite high speeds (along straights for example) and in these situations the Fox RC4 shock was significantly better.You have to understand that at the end of the day, all these products are just pushing oil through a shimmed piston to provide damping - and thus the primary area of concern is the valving itself. If the damping rate at the wheel is not suitable for the frame and rider, you've dropped the ball. To answer your suggestion specifically, BOS in France were rude had no interest in changing the valving, however my (excellent) local distributor was kind enough to offer me a refund and looked after me.
I will revalve it myself in the future, however that defies the point of the investment.For what it's worth, I also found the RC4's rebound curves to feel smoother and more linear, where the Stoy would tend to feel a little peaky / kicky where it shouldn't be. Hey Udi, thanks for your follow-up post clarifying your concerns. From my personal perspective of riding Bos suspension recently I found the compression to be absolutely spot-on but this does depend on working with Bos to get the right settings for your frame and rider weight. Yes, if the basic shim settings are off you will not be able to compensate via comp & rebound settings as they do offer a narrower range than say a Fox shock. This is intentional I believe as the shim/spring should put it in the right ball park.
Although this means the shock is less versatile than say a CCDB its not a big deal to have it re-shimmed if needed.From your three points it sounds like your shock was wrong for your weight, you tried to compensate by maxing shock C&R settings and were frustrated it didnt have the range to compensate fully for the base setting being out of whack for your bike & weight. I'd encourage you if you have it still to return it to Bos to be tuned correctly before you make your final judgement.For me the quality of Bos damping is a easily noticeable step above above both Fox & Rockshox offerings offering better control, traction and using its travel more efficiently. In my opinion this is pretty much bang on, and a good illustration of the pros and cons of fine external adjustment ranges. The BOS has the potential to work SUPERBLY on the right bike, for the right weight rider, but given the small range of adjustment available for any of the five or so factory tunes, vs the variation in leverage rate and rider weight in combination with relatively extremist tunes (they're x-treme because they make you do backflip barspins on your DH bike mid-run ), it seems reasonably common that you find rider/bike/tune combinations that simply don't work that well. If you're going to revalve it to suit then fair enough - but once custom tuning is introduced into the equation, there isn't actually all that much difference between any of the shocks on the market in terms of the performance you can get out of them. With valving changes and other minor alterations, I could quite seriously make an RC4 feel so similar to your BOS that in a blind test you'd be unable to tell the difference.Udi makes a pretty valid point - if you're going to pay THE absolute premium price for 'the best you can get' - it's reasonable to expect it to be like that without requiring further modification. I bought some brand new Idylle Rares in april this year, the last set of 2010 ones from R53.
They were flawless performance wise and maintenance wise in whistler for 3 months, absolutely loved how they felt! However, the high speed compression adjuster fell off, which I wasn't overly pleased about - When R53 eventually got back to me, apparently it was my fault and I must have been using the wrong tool (I used a 14mm socket as instructed) to adjust the HSC, which caused the grub screw and consequently the adjuster to fall off.
This was only after 2 weeks of use, and I followed everything in the maintenance section of the manual religiously - perhaps they should mention to check the grub screws that hold the adjusters in!I think the lowers have also twisted slightly, which is also annoying. Although it could be my eyesight, maybe I'll send them off and see what they think.I have a stoy on my 2010 demo, although it needs a revalve, apparently it was tuned for a demo by the previous owner (the shock was originally a ST01, the demo needs ST04). Currently running it on the slowest rebound setting, I found it too fast at first but now im used to it, but still next time i get it serviced I shall get it revalved so my current setting becomes a medium setting, so I can actually have a workable range of rebound adjustment.All in all, performance = great, but dealing with distributors can be frustrating. Hi All,This is an internet forum right? Somewhere people can express personal opinions right?So I would like to enforce that all my posts are an opinion based on riding BOS for a few years and are exactly that. And BTW I run an RC4 on my Summum now which I am very impressed with too as its just done a full season in Whistler without any dramas and feels like it did at day 1. So not just a BOS bigot!Steve with regards to your Dyno testing, I dont know your results and wouldnt understand them if you showed me.
There is no reference in my post to you or anyone for the matter so not sure why you decided to write that I was referring to your testing?Merry XMAS kids, hope you all got some BOS stuff under your XMAS tree this morning! Hi All,This is an internet forum right? Somewhere people can express personal opinions right?So I would like to enforce that all my posts are an opinion based on riding BOS for a few years and are exactly that. And BTW I run an RC4 on my Summum now which I am very impressed with too as its just done a full season in Whistler without any dramas and feels like it did at day 1. So not just a BOS bigot!Steve with regards to your Dyno testing, I dont know your results and wouldnt understand them if you showed me. There is no reference in my post to you or anyone for the matter so not sure why you decided to write that I was referring to your testing?Merry XMAS kids, hope you all got some BOS stuff under your XMAS tree this morning!
Service intervals are probably the one most amazing thing BOS has going for them, their tech feels and rides great but I really cant tell the difference in my bike between an RC4 and Stoy.Not to say they are flawless, I have actually blown 2 Stoys in a over the years as they had a problem on a batch with the main shaft seals blowing and even though RC4's seemed to have issues for a bit I never had any of mine. Luck of the draw?In my opinion and not based on anything to do with you guys testing BOS performs as good as anything else out there, what really stands it head and shoulders above the rest is the service and reliability. Thats the message I want to get across, well that and the fact that all RS stuff is crap!!!
(come on some one bite!)Now Im going to go ride my bike.Laters. Haha, service intervals are great but you blew two of them?I blew one of mine too. Yes they updated it, yes it's fine now.In short - BOS aren't perfect, neither is anyone else - they're not head and shoulders above anything, they just make some cool gear with a few imperfections just like everything else on the market. Fix the little bugs and they're great, but the same could be said for any other good suspension product.I have nothing against you personally, it's just the part where you signed up to a forum and raved on about something you clearly understand very little about - in particular dyno results you haven't seen, of someone else's (my) shock.If you love your gear, just go ride your bike - and I'll do the same.
Most high end shocks have a setup similar to this. Remember that the CCDB has a shim-stack on the main piston, and then the spring-controlled poppet valves at the reservior, those provide the 'user-controlled' compression damping, as you'd have to have a wacky concentric rod going through the shock shaft to reach the main shim-stack to 'preload' it or whatever. The avalanche and push shocks have a similar setup with a spring-controlled valve (there are also a couple shimz in there, but I don't think those are for damping based on the diagram), I've seen the RC4 internals and same thing, and so on. It depends on the complexity of the shock, but you are controlling low/high speed damping depending on the valving that is there. The main-piston is most likely 'high speed' and the 2nd stack in the reservior is most likely 'low speed' on simpler shocks, but there's usually going to be some interaction between them unless it has a more complex setup.
The reason you have two compression stacks (one in the reservoir bridge and one on the main piston) is to build up pressure between the main piston and the reservoir bridge via damping forces (oil flow through each compression circuit) rather than relying on the gas charge pressure to force the oil through the main piston. If you only had the gas charge pressure itself (say you had 200psi in the reservoir), once the pressure drop over the main piston became larger than the gas charge pressure, the pressure behind the piston (between piston and seal head) drops to zero ie a vacuum, causing extremely severe cavitation.Having a 2nd compression circuit between main piston and the IFP means that you can run lower gas charge pressures/higher damping forces without cavitation. Ideally, in terms of cavitation/consistency, the pressure drop over the main piston should be no larger than the pressure drop over the reservoir bridge circuit, however this is not always the case because as a general rule, the larger the amount of damping coming from the reservoir bridge circuit, the wider your range of external adjustment - which can be a good thing or a bad thing depending on how specific the manufacturer wants to make the initial tune. In the case of the BOS, the factory tunes are very specific and the adjustment range is narrow, whereas at the other end of the scale you have the RC4 and the CCDB which have very wide ranges of adjustment.Having a 2nd compression circuit also provides an easily accessible point on the damper for external adjustments - since you typically have your rebound adjuster in the shaft of the shock, it'd be extremely difficult to get any compression adjusters working on the main piston. So as I said the Stoy is a nice chassis but there were a few problems with the stock shock that seemed to be replicated on the dyno, so I made a few small changes.First issue was the rebound being too fast unless the adjuster was fully closed (which was also affecting compression damping), so valving the rebound stack firmer fixed that, allowing the adjuster to be run further out.
Tested this separately before moving on.The second and more significant problem was compression spiking at high shaft speeds. Usually taking a few shims out would be sufficient, but the stock HSC port area on the BOS piston was quite small (3x 3.4mm holes) so I decided to enlarge them to a generous 3x 4.5mm. Problem then was I needed a larger face shim, which was going to cover up the rebound entry ports, so some extended side entries were made.After some beefing up of the dual-stage compression stack to deal with the extra flow area, all seems to be working well. Excited to get some proper testing in on the new setup.Changes to the piston. The Legend has no progression in its leverage curve near the end of stroke (it actually becomes regressive), so I'd say the RC4 is the best shock for that frame, as it caters well for this characteristic with its position-sensitive compression damping (while regular shocks like the CCDB and Stoy do not).
This will let you run an optimal spring rate without trying to compensate for bottoming out, and thus allow for better bump absorption. If you go this route, make sure you get the 2011 or later model RC4 as there are some important updates.I am not sure of the exact differences between the Stoy ST01 and ST02 tunes (mine was an ST04 originally), however I believe the performance of the HS valving in the Stoys (at least the two I have owned) is less than spectacular, and while I am fairly happy with mine (actually spent last weekend testing it in a new frame), it is not really a BOS shock anymore as the piston and valving are both heavily modified.The reason for the top out can be one of two things. I think on earlier versions of the shock there were a few failed top out bumpers (haven't had any problems with this personally) - but all of them will have a slight top out as there is no hydraulic top out implemented on the rebound port on the shock shaft. Most mainstream shocks (DHX, RC4, Vivid, etc) have a teardrop shaped port that increases rebound damping heavily immediately before top out. If it is just a light thud at top out then it is normal (there is a rubber bumper internally).
Bos Idylle Rare Service Manual Review
If it's a loud clunk then there may be a problem.