Pop quiz: how many bikes employ a Macpherson strut rear-suspension design these days? The answer is not many, but the French Canadians at
Resistance Bikes are working at bringing a new Macpherson strut design to the market, and it's a downhill bike no less. But wait, that's not its only trick... The Insolent features an integrated shock that's located
inside its carbon fiber toptube. Oh, and there's a belt-driven Effigear gearbox bolted to the bottom of the frame.
You know the bike is interesting when its rather exotic gearbox is only a sidenote.
As others have already pointed out, the bike's shock appears to use part of a Fox 40 stanchion tube, which is quite clever when you realize that the integrated shock is much more of a load-bearing element in the frame than if it was activated - and protected from side loads - by a rocker link of some sort. The 40mm diameter of the stanchion no doubt helps matters, but I hope those carbon chainstays are thick and beefy to assist in minimizing the side-loading of the shock. Hey Fox, how do you feel about a 40's stanchion tube being diced up and used for a shock?
If you're wondering about the large swept area of the 40mm stanchion and the added friction that would come from that compared to a standard-sized shock stanchion, I can't see it being an issue.
Afterall, a Fox 40 obviously uses two stanchions and a one-to-one ratio, so I doubt that the friction from a single, short 40mm diameter stanchion would be noticeable when you factor in the bike's leverage ratio that's probably somewhere in the neighborhood of three-to-one.
While Resistance Bikes doesn't supply much information about the design on their webpage yet, it looks like the shock itself is actually a thin aluminum body that's pushed up inside the toptube and then threaded into a cap that serves as its forward mounting point.
There are no non-drive-side photos of the bike, but you can see what looks like a single-sided bolt hole and two air valves if you look closely at the renderings, with an air piston dividing the chamber into two sections.
To support the shock, Resistance Bikes has manufactured a large bushing and sleeve that's either pressed or threaded into the back of the seattube, shown in the photo to the right.
The Macpherson Strut layout requires the seattube to sit well forward relative to the bottom bracket, so it's at quite a relaxed angle to have the seat in the right spot. No word on what they're using to control the stroke, although it looks almost like a shrunk down fork damper has been fitted inside of the shock body. With no traditional link to control the rate curve, we're eager to see some suspension graphs. We'll keep you posted on that one, but Resistance Bikes could be using something off-the-shelf or manufacturing their own damper.
There's no denying that this thing is cool looking and extremely interesting, but I also have to ask
"why?" Translating the French on Resistance Bikes' website reveals that they've gone this route because
''the integrated structure of the Resistance Bikes frame reduces the amount of material required to achieve satisfactory rigidity. The direct line between the handlebars and the rear wheel transmits forces optimally.'' In other words, they're saying that the Insolent doesn't need links to achieve the rigidity that they're looking for.
What else? Well, there's that belt-driven Effibox gearbox hanging off the bottom of the bike, and slotted dropouts at the back to tension the belt correctly. It's a single-pivot design, and the main pivot is at the gearbox's output, so there's no tensioning roller required, either.
Resistance Bikes doesn't quote any numbers when it comes to weight, geometry, or travel, but the Insolent likely sports somewhere around 200mm of travel and, because it's a prototype, is probably built heavy enough to brush off any testing abuse.
Of course, this isn't the first bike with a hidden or integrated shock, but you have to admire the sleek lines of this garage-made beauty. There's no word on pricing or availability, but here's hoping that this isn't one of the many one-off prototypes that drop jaws only to drop away into the ether and never be seen again.
Photos from Resistance Bikes
Seriously though how would you, or how did they service shocks with that design without taking the whole rear end apart?
Frig that sounded dirty also.
Great f*cking markting though
THESE are mac-struts...
www.retrobike.co.uk/forum/download/file.php?id=97856
www.pinkbike.com/photo/13554773
www.retrobike.co.uk/forum/download/file.php?id=164133
THESE are mono-shocks...
blog-imgs-55.fc2.com/l/u/c/luckymotors/2012091001204288b.jpg
i.pinimg.com/originals/f3/30/2d/f3302d44936b22c0161d4f08f3181881.jpg
forums.mtbr.com/attachments/santa-cruz/635757d1359601749t-tazmon-roll-call-tazmon7-copy.jpg
i.pinimg.com/originals/5f/36/5a/5f365a52b7a8da0302dbc3f5d9666e1e.jpg
I KNOW i've made this point before... when doing reviews of modern spins on old technology...please turn it over to RC... as he was actually a frame builder/designer in the heyday of these designs, and produced mac-struts himself (Mantis Profloater) and thus won't get the design terms wrong.
www.mtb-news.de/forum/attachments/img_8842-jpg.511421
images.singletracks.com/blog/wp-content/uploads/2011/01/muddy_fox.jpg
I'm a bit lost on the whole Mac Vs Mono thing though. With a Macpherson strut on a vehicle, the shock is mounted solidly to the main frame / chassis, yet on a bicycle, the term is used for when the solid mounting point is at the bottom of the shock? It's not hard to see why the author got it 'wrong' unless I am missing something here?
the Kestrel Nitro. www.flysfo.com/museum/exhibitions/3060/detail?num=7
this thing was built in 1988 way ahead of it time
Yep... but that's how the creators of the design (largely Horst Leitner and the other brains at Amp Research) named them in ohhhh..... 1992.... so 25 years ago and thus establishing the naming convention/design criteria to qualify as one for everyone that followed. Mono-shocks had already been "invented" and named as well, and popularized by Boulder. The name was derived from a motorcycle suspension design though again...this was a matter of adopting/borrowing from an existing name that consumers might be familiar with. It was chosen to set itself apart from cantilever/walking beam bikes (and yes with few exceptions, every mountain bike has used a single rear shock) like Brian Skinner's Descender.
forums.mtbr.com/attachments/vintage-retro-classic/273744d1182465882-brian-skinner-descender-completed-descender_01.jpg
I didn't also set out to cite EVERY example of a mac-strut or a mono-shock. I simply picked more well known ones that were likely to be familiar enough to pinkbike's younger demographic (likely because their dad still has his in the basement). The original specialized Ground control A1 rear suspensions for example, were mac-struts also designed by Horst Leitner as a "cheaper" to produce model than the Stumpjumper FSR he'd already designed for them.
forums.mtbr.com/attachments/specialized/365709d1212463884-1996-specialized-ground-control-a1-comp-a1.jpg
Kestrel later had another full suspension bike though which did see production, the Rubicon which was a walking beam linkage.
Kurt Stockton's DH version and the Rubicon Pro employed twin shocks but they were also available in a single shock version.
ep1.pinkbike.org/p5pb13761429/p5pb13761429.jpg
forums.mtbr.com/attachments/cannondale/772971d1361156688-gosh-i-hate-right-all-time-kestrel_rubicon_sml.jpg
Here... read the story on the bike... I had typed out a nice couple paragraphs about the bike including the part how double shocks let them run less air pressure ( a good thing since the Fox Alps shocks were unreliable at high pressures) but also boosted the wheel travel, and the tall gearing and dildo length stem, then remembered there was an article here in august 2016 about the damn thing, as well as the pro's closet also did a write up about it.
One detail changed from the original 1995 bike worth noting is the fork. Judy forks didn't exist in 1995. Rockshox was developing a new fork at the time, what eventually became the Judy model, and it was called the Diablo, and available for pro riders only. They made roughly 200 of the things and the name was taking from the Lamborghini Diablo which was then replacing the Countach as their supercar model. Then Jamis bicycles cried foul pointing out that they'd had a US trademark for the bicycle industry on the word Diablo (as its one of their model names) since the early 80s. So... new name was chosen. Also...the Diablo's all had aluminum thru-shaft cartridges for the oil damping which were reliable. 1996 production forks got a plastic composite cartridge which failed regularly but was cheaper to produce. There was subsequently a recall over them when TENS of THOUSANDS were failing, and they went back to aluminum cartridges.
theproscloset.com/museum/mtb/kurt-stocktons-1995-kamikazi-rubicon
www.pinkbike.com/news/1995-kestrel-rubicon-comp-now-that-was-a-bike.html
My bike company was buying AMP Research rear suspension kits from Horst at AMP for our prototype frames back in '93.
The shock unfortunately was a "stressed member" (rigidly attached to seat stay) causing multiple shock failures due to constant side loading of the shock stanchion/bushings/body.
As the bike had the horst pivot (chainstay/dropout) we got the lovely active feel and controlled braking in the chop, but the length of the mac-strut was insane (from forward shock mount on downtube to rear pivot) and super flexy. We built our own version with seatstay pivot to explore, which solved much of the flexure but the suspension feel was more constipated.
We switched from AMP's coil/oil shock to Noleen's with much better success but still saw accelerated wear on the shock parts due to Mac-strut. Our own design (never made it to production) used our own 4-bar swinglink with horst pivots.
AMP then switched to the B-3 design with the seat link and seat tube mini tower (to accomodate shock) which soon led to the FSR deal with Specialized.
Thankfully this new design is decoupled with a pivot, which should help no doubt
Another mac-strut, that may not look like it at first, that more people would remember, is the Maverick. The shock pivots on the frame and is integral to wheelpath. It just has the short pivot close to the frame not the wheel.
forums.mtbr.com/attachments/maverick/55825d1108083158-production-maverick-ml8-ml8.1.jpg
Because the shock isn't that inegral here, I would think load is less than a tru mac-strut so I wouldn't worry about wear, like some are. Mavericks with 32mm loaded shocks are over a decade old now with minimal wear.
ahem... will it be available in white?
''Pawn Shop chronicles''
Alton: You calling me a racist?
Johnson: Well, you don't like black Santa Claus. And last week, you told me you don't like black porno.
Alton: Now hang on a damn minute. Now that's got nothing to do with racism. I like black chicks in porno movies. I just don't like 'em with the black guys in them, that's all.
Johnson: Why come? They make you feel inadequate?
Alton: No. Because their di***s are so dark. They get to f*****g, their di***s get wet, they get glisteny and shit, and it's hard for my eyes to unfocus off it. Make me sick.
Johnson: Eh, well, I guess you got a point.
I agree on the contact part though
Epoxy can be an issue at high heat, but I doubt this will be a problem at the kind of temps coming off a shock (brake mount temps are more of a concern).
www.balfa.wooyek.pl/Belair/balfa-belair-frame.jpg
www.pinkbike.com/photo/13047729
The swingarm shock mount moves in an ark, not a straight line. For this reason, the shock has room to move for the radial swing of the swingarm. If it was mounted rigidly, there would need to be an additional pivot(hence why the design in this post has two pivots)...
A link requires that the shock be able to move around a pivot of it’s own.
Also, essentially every impact a normal 40 (any fork) takes is sideloaded as f*ck as well.
a 40 has a dual crown and and that arch on the lower to help with side loading.
A fork does take sideloads yes. However a fork has two stanchions and two bushings per stanchion spaced 3 or 4 inches apart. Two features not included in this frame design. Furthermore, even with two stanchions and four widely spaced bushings, forks still suffer from huge amounts of stiction compared to a traditional rear shock setup...
I think you will find that a fork that is ridden hard needs its bushings replaced after a couple of years max. Put all that load through a single bushing as in this design and its gonna last a couple of months max.
I do also agree that forks do suffer from stiction, but think it is mostly due to the 1:1 ratio. And bushings in forks absolutely do take a beating as you suggest below.
I think the fact that there are more bushings and stanchions in a fork matters, but it is needed much more in a fork. The side loading is far greater simply because the force is applied at the bottom/front of the wheel, some 27" away from the seals and upper bushing. (I'm really talking the wheel taking impacts from the front, not actually from the side. and as such the arch doesn't really do anything as mccracken suggested)
It still doesn't help the fact this bike is going to have a shitty leverage ratio at end of travel.
Now I want you to get really kinky and build one with a linkage fork.
www.pinkbike.com/news/structure-cycleworks-linkage-fork-crankworx-whistler-2017.html
This idea isn't new www.bikeman.com/images/stories/Museum/boulderdefiant1B.jpg but this is a really cool evolution. These are the kinds of ideas we should be exploring.
The frame has horizontal slots in place of traditional dropouts, but in the first photo they appear to be filled with form fitting alloy 'washers' when the rear wheel is in place. Is this because the slots are necessary to install the rear wheel into the belt but then will always be in the same place? Assuming since it has a gearbox the size of the front and rear drive cogs or the belt will never change so the rear axle will never require any type of micro adjustment for proper fitment?
I am curious and have no experience with belt drives or gearboxes. If it was explained in the video I apologize, I am on a limited connection.
Hope i'm wrong, cause i really like the design(although the frame is made of plastic;-))
www.youtube.com/watch?v=psbxL7o-6ZA
It often happens with garage-made products which may have good ideas but limited resources, though it also happens with "big" products (it happened with the first picture of the Nomad 4 with the shock in low position and long rocker link or whatever it's called, then everyone liked it when it was officially unveiled with nice colors etc).
On the other hand, it may be a crude clue that a product still needs refinement.
The ARBR may be technically awesome, I find it too intricate, as if the designer kind of lost his way throughout.
There's a saying that goes along the lines as "what is clearly thought is clearly expressed".
Though I must say that it looks a bit like a carbon version of the Commencal Supreme SX.
Maybe those long travel enduro bikes technical specificities are taking the design out of our "confort zone".
Many thought the longer/lower/slacker bikes looked weird at first, if not ugly, but it slowly established itself.
This one, despite its shock design prone to garner a lot of 8 y.o. jokes as demonstrated here, seems quite refined, to the point. It's clearly expressed and maybe it means that it's clearly thought.
I just wonder, while I'm no engineer, if the seatstays/toptube alignment shouldn't rather happen at SAG, under load, than as it is now, without load.
The ARBR is a fantastic design function wise, but its looks aren't for everyone: Gets trashed.
This Insolent bike on the other hand is a terrible design function wise, but looks kinda cool and gives people an easy excuse to make dick jokes. People lap it up.
Just that front triangle still looking a bit too bold.
Maybe it's just straying a bit too far from the "bike made of tubes" design we're all used to.
Everyone may have praised it if it were a bit more smooth and hollow à la Ibis Mojo.
Take a look at the labels on the chart Steve at vorspring put together for their Tuesday Tune on leverage ratios.
www.pinkbike.com/news/the-tuesday-tune-ep-12-leverage-rates.html
I've never seen anyone lable a rate graph like that guy in the video did I and I personally think he's needlessly confusing people. I'm all about simplifying and standardizing this stuff so the public can cut through the marketing BS and make informed decisions.
I laugh when you try to dismiss what Steve puts out when it's the standard terminology that you just don't have a clear understanding of. He's the one person doing more than anyone to educate people on here about suspension and cut through the BS. The terms rising rate and falling rate have been around forever and have always had a consistant meanings.
Have you checked out andrextr's youtube channel and info on vitalmtb? He's done the best job at presenting info on how progressive suspension is in a simple way and putting useful numbers to it. I like how he just puts out numbers on each bike for what percentage of progression there is and the bottom out force (based on holding sag % the same on different bikes).
www.youtube.com/watch?v=4fYfdlKIon4
Still cool machine, hope it get to production
Maybe they just didn't have the time to translate everything yet.... The bike is supposed to be available on summer 2018 so I'm pretty sure they are still working hard on the bike and everything else and then they will take the time to do an english version as well!
French Canadien you say?
Lol
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