Bike Check: Loic Bruni's Specialized Carbon Demo - Crankworx Rotorua 2016

Mar 13, 2016 at 21:30
by Richard Cunningham  


Loic Bruni's new Specialized Carbon Demo was wired up for data acquisition at Rotorua, presumably to dial in the suspension to suit his riding style. Pure Agency, the team's owners have been using real-time information gathering to dial in team bikes for some time, but to our knowledge, this is the first time the blinking boxes and accelerometers have been used while under the red Specialized tent. Evidently, it worked well for Bruni, as he trounced the field in New Zealand on a World Cup worthy track that saw a number of top names hit the dust.

Bruni's Demo was also sporting a CNC-machined custom rocker link - an accessory that has been popping up in various configurations on team bikes since the new design, with its concentric swingarm pivot and single-sided shock, appeared under Troy Brosnan and Aaron Gwin. Who knows where Specialized is going with it, but this iteration of the shape-shifting rocker has a small shock extension apparatus bolted onto the eyelet of its RockShox Vivid damper. Adding a further element of mystery was the use of a 30-millimeter spacer below the shock's spring. The spring appears to be steel and has a reduced coil count.

Loic Bruni Specialized Demo bike check 2016
Not used on his race run, but reportedly, Bruni's Demo was bristling with electronic data acquisition hardware during practice.


Loic Bruni Specialized Demo bike check 2016
An accelerometer was placed on the seat stay, just behind the rocker pivot location.... Note: bighit117 says: "If you look closely, its actually a pressure sensor that's mounted in-line with the rear brake hose. They were probably watching how hard he was on the stoppers. I see them all the time being an industrial electrician."
Loic Bruni Specialized Demo bike check 2016
Come race time, the pigtails to the sensors were taped and secured to the frame. Notice the spacer under the shock spring.

Loic Bruni Specialized Demo bike check 2016
A tell-tale hole in a cobbled up handlebar mount probably held a button or toggle switch that sent commands to the telemetry system.

Loic Bruni Specialized Demo bike check 2016
The short shock extension link appears to have been made in a hurry. It may function only as a place-holder to adapt a different length shock.
Loic Bruni Specialized Demo bike check 2016
The extension bolts directly to the standard eyelet of the Vivid damper and pivots on the rocker.


MENTIONS: @officialcrankworx / @Specialized / @SramMedia / @one-industries




122 Comments

  • + 393
 Specialized know what they're doing. I have two of their water bottles and no leaks after two years!
  • + 35
 Nice dude!
  • + 61
 Any telemetry data?
  • + 37
 pics or it didn't' happen
  • + 9
 hahahahahhaa
  • + 12
 Specialized water bottles are in a class of their own. Come on Trek.
  • + 3
 i didnt see any of those electronics on gwins YT hmmm
  • + 1
 I see they borrowed a Trek Sessions linkage to get the rear to work for the Bruni of the Sinai, Allah Gwin tastic! looks ugly compared to Gwins, bet you wont see that on a YT!
  • + 1
 Have you even tried a purist?
  • + 0
 hes had this for the last 2 years an it was only very slightly interesting back then
  • - 1
 Yeah there water bottles are soild. I also use their bottle holder which is ergonomically suited to my right handed disposition. As a brand I believe they avoid doing any real research on their bikes and just throw parts together at random; they focus heavily on R&D for their accessories bottle holders, jerseys and padded short shorts. The random shit they throw together works though and #IamSpecializedretard .
  • + 190
 Secret NOS button
  • + 95
 Bike check aka let's try to decipher the shock link
  • + 67
 Pretty good looking bike, but they didn't even specify the brakes, or the other components in the article. It seemed more like a "bike glance" than a "bike check".
  • + 17
 Luic doesn't use brakes Wink
  • + 19
 Plus they're Avids, so nobody wants to know.
  • + 3
 Guide levers and code calipers by the looks of things. Which is what I've got now and it's awesome.
  • + 6
 don't lie
  • + 36
 The main propose of the custom rocker link is to increase the progressivity by 10% comparing to the original Demo's linkage. Demo is a great bike, but IMO the original linkage it is too linear for a DH bike...

www.youtube.com/watch?v=V5UFr-WuS6w
  • + 8
 I come across these films at the weekend. I sat and watch everyone of the suspension series. Great work man. it was just what I was looking for. I will definitely be following your work
  • + 14
 Thank you man! I'll be keep doing them Smile Bye
  • - 3
 the videos don't take into account what Ohlins has done to the shock for the Demo.
  • + 16
 Hi jaydaw. Yes, you are right. But that's because kinematics don't depend on the shock. The amount of anti-squat, brake independency, axle path and leverage ratios are exclusively dependent on the linkage design. And the reason that pro's use a different linkage on the Demo is to increase it's progressivity to a more "standard" value for a DH bike. I ran the simulation for that linkage, at it increases the progressivity of the bike without changing the others kinematic parameters. So, kinematics play a very important role independently of the shock tune. Of course you can tune the damping of the shock to match the kinematics, but IMO with the standard rocker link you can't achieve a good amount progressivity without having harshness on small square edge bumps. Bye Smile
  • + 5
 Awesome man! Smile
  • + 1
 @andrextr: I do not really understand a lot of kinematic but all i need to know is, is the new demo a bike worth to buy or does the link system suck - i read a lot about a kicking rear end.... is it true what some people are writing?
  • + 1
 @supersante: Overall the bike is nice, but IMO the linkage is a bit too linear. It should be more progressive. This is why Pro riders use a different rocker arm in the Demo. The anti-squat (pedaling efficiency) is also very very low. It could be a bit higher. Not sure what do you mean by kicking rear end, but that can be a shock tune issue and not the linkage (either too much compression, causing spiking and kicking, or, fast rebound causing also bouncing after big hits). Bye
  • + 21
 Spring and spacer?....

sa-springs.com/about
  • + 7
 www.superalloyracing.com He is on the 140mm 425lb DH Light component.
  • + 3
 Seems an EXT/SA steel spring..
I'm using it on my ccdb and works great..
  • + 12
 From Super Alloy Racing's website:

"SAR enjoyed multiple podiums at every World Cup in 2015... ...with Loric Bruni winning the downhill word championship in Andorra on a 400lb SAR Spring."


From this article:

"Adding a further element of mystery was the use of a 30-millimeter spacer below the shock's spring. The spring appears to be steel and has a reduced coil count."

Did they even speak to Loic about the bike?
  • + 4
 While I'm no WC racer, I bought one and they are super light! Cheaper than titanium too.
  • - 4
flag will-burr (Mar 14, 2016 at 14:34) (Below Threshold)
 Save weight with the spring, then add it back with the spacer... Just what I want???
  • + 2
 The spacer is plastic so does not weigh much and it necessary since the Super Alloy Racing Springs only come in one length. Also the spacer acts like a bearing and allows the coil to rotate slightly as it compresses, leading to better performance from the coil. It is what you want because those springs are the ducks nuts, most accurate spring produced for MTB, guaranteed to be within 1% of the printed poundage which cannot be said for most other companies.
  • + 1
 riding the SA spring for about a year now (2013 demo, vivid). works great! its about 300g lighter including the plastic spacer compared to the original RockShox spring..
  • + 1
 A shorter spring probably ramps up quicker than the full length one
  • + 1
 They are linear springs, so the length of the spring doesn't effect how it ramps up.
  • + 1
 @will-burr - it weighs 37 grams.
  • + 1
 Yeah the point of a coil is to stay linear, which means it doesn't ramp up.
  • + 19
 Not really a bike check, just speculation about his rear shock and telemetry equipment
  • + 1
 They're not allowed to do a bike check, otherwise they'd discover the anti boost 135mm rear hub spacing, and Pinkbike's ad revenue would drop to 0.
  • + 13
 would have seen this months ago if the haters wernt so busy trying to spoil the fun.

New link for more progressive rate, lots of data logging and testing. No shorter or custom length shock. The extender built into the link is so that you can build a link to do what you want without being limited by the stock eye to eye length.

the spacer on the spring is simply because the light spring is short and the Vivid shock body isn't threaded all the way down. Lots of bikes in the pits with this, nothing crazy.

www.pinkbike.com/news/specialized-gravity-team-testing-winter-2016.html
  • + 11
 That's not an accelerometer on the seat stay, it's actually a rear brake pressure sensor.The data logger (Aim Evo 4) actually has it's own internal accelerometer for measuring g forces along 3 axis. Looks like they're using 6 channel feeds, I'm going with front/rear wheel speeds, front fork position, rear shock position, front brake pressure, and rear brake pressure?

Just stay away from those weather pack connectors guys. Use some Deutsch Autosport connectors ty-rap zip ties instead! Little more compact and durable. Pretty cool to see automotive motorsports data aquisition equipment being utilized on the DH circuit now. It would be pretty neat to see the data stream from one of these bikes after a practice run.
  • + 7
 Totally correct! The pressure transducer is T'd into the brake hose! Nice catch
  • + 9
 You'd think they could get all the data logging tech into a SWAT box on the downtube!
  • + 5
 I think you guys are missing the reason for the shock 'extender' which isn't really an extender at all. The shock actually appears to be at stock length, but the location of the mount on the rocker link is much farther back than on a standard Demo (look how close it is to the rear tire). Aside from altering the rate the extra length makes up the difference in eye-to-eye distance. Gwin and Troy had much shorter versions of the same design on their custom links last year.
  • + 8
 SA Springs and spacers. Now there's a story right there. Check them out..
  • + 4
 Ya mean that adjuster thingee would allow me to swap out shocks and run non-specialized-proprietary shocks? Why would anyone want to do that?
  • + 1
 There is a article about that last month for the fsr shock.
  • + 3
 Im pretty sure the stock link on the demo runs a conventional mounting position.
  • + 1
 Well dammit I was trying to be a sarcastic jackass and I've failed on multiple counts. Anyway that's cool that you can swap this out relatively easily on a demo. And I did see that enduro link. Got one on order.
  • + 2
 I'm surprised there isn't more snaps of pros using data acquisition, or perhaps they just do it in secret. I'm sure it's a lot more accurate for mechanics and engineers to assess what is going on rather than a rider description.
But often I think at the end of the day fast guys and gals, are just as fast/brave/nuts on a poorly or well set up bike.
I like numbers too much for my own good sometimes.
  • + 3
 They don't do it much on the circuit. Everyone does it in the off-season from my understanding though. Yet they have to do it at the races. People should give more credits to Loic's mechanic. This guy -Jack- is doing an hell of a job. Not a real surprise with the kind of Motocross background he seems to posses.

Can't wait to see what the future Demo will look like! I was lucky enough to test ride Lapierre's latest DH bike and I have to take my hat off to Bruni's mechanic and the Lapierre R&D guys. That bike handles like a MX!
  • + 2
 Ahhhh, I'm glad you said he had a Moto background - I wondered where it came from. MX is still a way behind four wheeled Motorsport, but it's great to see data being used increasingly & in the public eye.
  • + 1
 Nicolas Vouilloz was using telemetry on his Sunn Radical + back in 1997! I do remember watching him doing some tests at our local track. Even the ECU mounts were welded to his frame, not like some kind of zip ties . Damn that makes me old :'(.
  • + 1
 Jamesdunford@ how is MX way behind four wheeled motorsports?
  • + 1
 @MX298 It's quite simple mate. In terms of data acquisition systems MX/SX is at least 10/15 years behind 4 wheeled motorsports -maybe 20-25 years according to a friend of mine-. In the late 90s, Olivier Bossard -now CEO and chief designer at BOS suspensions- joked about the fact that the sort of telemetry he was using on Nicolas Vouilloz was barely used in MotoGP -it was the 500cc class back then- and was unknown to MX/SX world at that time -it's no joke-. From the mid 80s, data acquisition systems is the norm in Formula 1. Even amateurs were using it in the mid 90s for rallying or formula Ford/Renault.

It is not necessarily a bad thing. If you don't have an army of people looking at the datas you won't learn s*** with it. And those people they don't really work for free. But hey, in the last 10 years and since the 4 Stroke is the norm, things have changed massively.
  • + 1
 Your dating your self. Two strokes. . . . . . . . For MX It's more complaceted then sticking a potentiometer on a shock and reading the data. Rider input, track conditions change, Feel is huge. Big MX teams have been using this info to confirm what the rider is saying for some time. Remember in the USA there are rules on MX bikes, production rule, traction control etc. . . .Now motogp is a whole other thing. And I got a Gamma.
  • + 1
 @MX298 How is MX more complicated to feel than F1 and MotoGP? It seems like going 20% the speed and having 10x the suspension travel would make it much easier to notice small difference in performance. And I'm really asking here because I have no experience with MX's at all, I'm just questionning myself because I can feel a loose spoke on my bike in 10 feet but I couldn't tell if my car tires were flat.
  • + 1
 I think they are referring to the fact that there are most likely more variables in MX, like in F1 you have other racers and weather. However in F1 I think it is reasonable to assume that the surface will be very consistent and the track will be the same the whole race ie; no ruts developing or lips changing.
What I'm getting at is how it would be harder to notice a minute change in set up when the course you are testing on changes with every lap.
I don't have much experience with motorbikes and am just assuming here but I think what I have said makes sense?
  • + 5
 Put him on a Huffy, hes still going to win medals!
  • + 4
 Super Alloy Racing Springs for the win!
  • + 2
 Why is it that world champions still continue to win on 100ish dollar rims vs $500-$1200 carbon rims? Oh yeah... Cause it's a status thing.
  • + 9
 Or maybe the pros have very different requirements from their bikes to us. Nah wait, everyone on pinkbike is either an expert mechanical engineer, or a pro rider who just hasn't had their big break yet. Or maybe their both.
  • - 1
 Those look like they might cost more than $100... Just sayin.
  • + 2
 EX471s are like $100 everywhere homes. rim, not wheel.
  • + 1
 They do get new wheelsets for racing and practice for basically every race. Danny hart was rolling on 533D's for a bit last year even haha.
  • + 0
 Carbon rims suck for anything else than XC and "post the pic of your bike" forum threads. If you want to make them last you need to make them 450g-ish and that simply gets you into alu territory. No matter what you do with CF, the only reliable way to make it less brittle is to make the element thick. Those Enduro/AM rims still aren't indestructible. With XC or road, it's a different story since you want a significant weight drop into 300-ish area, and at those weights alu rims are soft as cheddar cheese. So here you do win both weight and strength. I still think pros use alu rims because they provide a smoother, more compliant ride, eating chatter in a better manner. I had carbon rims and I will never ride them again, even if I was given ENVEs for free.
  • + 2
 I've heard of teams going through dozens of wheels during the course of a race, with warm-up, qualifying, and race runs, for multiple riders. Some successful teams do ride carbon rims (e.g. Syndicate), but not everyone can be sponsored by enve haha
  • + 2
 Syndicate is coped with ENVE since they were making swingarms for V10s. AT
  • + 0
 All the money specialized have and they have extension bits different links. Shouldn't all this have been soughted when the bike was released. i know different athletes want different feels on the bike, but it seems like most good bikes only need a suspension tweak or upgrade if a bike is made right.
  • - 1
 The original linkage was designed to work with a special tune Öhlins ttx, was i not? Bolt any other shock in there and apparently metal has to be cut or the shocks won´t cut itWink ...
  • + 20
 No, that is a sign of a company that takes racing seriously and adapts the original design to the rider and new data. Giant doesn't play around with bits on the Glory, because they are so fond of how much they have dialled the design after years of research at NASA. No. They don't, because like most companies out there, they just don't care. They draw a new one every 2-4 years. So I am personally quite impressed with Spesh doing experiments and testing in the open field.
  • + 1
 Any ideas what this shock spacer could be used for? I've seen this a few times already on pro bikes but don't have the slightest clue what it could be
  • + 1
 It is often used in conjunction with a SA Racing Springs spring. Their spring comes in one length and the spacer is used to make it fit different shocks. Aside from that it also reduces coil bind by acting like a bearing and letting the coil rotate around the body as it compresses, this increases sensitivity and allows for better shock performance.
  • + 3
 It's hard to get excited about just another Demo...
  • - 1
 Man,there's too much technology going on in this,i'm about freedom,about simple yet effective rides,simple bikes for simple smiles,just my opinion,but that's what i love about bikes in general,you don't have to worry about many things,you just hop on it and ride..
  • + 2
 Don't worry, nobody is bringing the data acquisition equipment to the trail head on a Sunday morning. You can continue to ride blissfully unaware of technological advancements...he writes on a message board on the Internet.
  • + 3
 Downhill is becoming an aerospatial department
  • + 3
 No complaints about chainstay length!
  • + 2
 The most beautiful part of the bike is the CNC rocker link.
  • + 1
 chain guide is too weak....i have one ...tape it or fall apart,sorry for my bad english
  • + 2
 The real heroes are the zip-ties
  • + 1
 That's the shoot where Tippie got Loic's Braaaapp, non? "there is no one here"
  • - 1
 Rotorua is pretty tame compared to some tracks we will see later this year, he was prob running a shock with a little less travel, something he might use at a place like Pietermaritzburg
  • + 1
 Have you ridden the track or walked it, or did you just see the couple of sections that the cameras showed
  • + 1
 @groovygreg10 just me or does that front rim look like a 26
  • + 1
 I don't think anyone can say this bike 'looks like a trek session'
  • + 1
 The MTBers at the NSA will be laughing all the way to the bank
  • + 2
 Wowzers
  • + 3
 i just made a mess in my trousers
  • + 1
 What size wheels n tires, what specialized tires is using?
  • + 1
 27.5" Butcher DH
  • + 1
 it looks like a...no it not look like a Lapierre
  • + 1
 These last bike checks have been leaving something to be desired...
  • + 1
 ...in a hurry. Pleaaaase!
  • + 0
 My guess, shorter rear shock, dont really know why he would do that, and spacer for spring ramp up + weight savings?
  • + 3
 www.superalloyracing.com for spacer info and spring info.
  • + 2
 That's the spring I want. Works on shocks with different sizes, and only a little more expensive to get then the Fox SLS. Once my frame sells, I will have the same. I think it comes out of Germany. The spring rates are supposed to be very accurate.
  • + 1
 It doesn't appear to be a shorter shock. The mount is father back on the rocker than stock, the 'extension' is to account for the extra eye-to-eye distance not a shorter shock. The sum of all these changes alters the suspension, presumably making it more progressive.
  • + 2
 Pretty sure it's the new "protour" edition rocker.
  • + 1
 Comes out of England developed by Dave Garland who wrenched for Danny Hart. Yeah correct they are within 1% of the printed poundage.
  • + 1
 So yeah, what's up with that spacer?
  • + 2
 the vivid shock body isn't threaded enuf fir a short spring so hello plastic spacer
  • + 10
 Specialized told me its basically a cockring for your dampner.
  • + 0
 I hope that didn't make in Aarons in there calculations. That could of cost specialized the gwin.
  • + 10
 I CNCed what you did there.
  • + 2
 Puns on pinkbike?? I'm shocked.
  • + 1
 Another beautiful sport ruined by money. Can't we just ride and have fun?
  • + 0
 at least we know he has joystick handle bars and a specialized frame.
  • + 0
 i dont like the rear triangle on the new demo 8s
  • + 1
 droooollllll
  • + 1
 nice chain guide ....lol
  • + 1
 too weak
  • - 1
 seat looks pretty high for a dh bike
  • + 2
 it seems like a lot of the racers run seats around that height, they like the control they get with the inside of their legs I think?
  • + 7
 Or the fact that the rear wheel needs to come 8ish inches upwards on compression?
  • + 2
 Yeah, looks about the minimum height he could have it before the wheel starts hitting the seat itself.
  • - 2
 aaaaaand no one cares
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