Here's Your Single-Sided, Carbon Fiber DIY Linkage Fork

Feb 21, 2020
by Mike Levy  
Ashley Kalym homemade linkage fork.
Status quo? Not so much for Ashley Kalym.


On a scale of one to ten, how much of a do-it-yourselfer are you? Burnt-out lightbulbs and hanging picture frames are the limits for some of us, whereas others are happy to DIY their way through just about anything short of a shuttle launch. Back in 2018, we saw Jean-François Boivin's homemade carbon downhill bike that used a gearbox and a stanchion tube from a Fox 40 for its rear shock, as well as Vladimir Yordanov's dual-link carbon downhill bike.

Next up in the DIY Hall of Fame is Ashley Kalym with his 160mm-travel single-sided, carbon fiber linkage fork.

Most modern suspension forks all follow the same basic principles: Two stanchion tubes sliding on bushings, a set of lowers held together by an arch and axle, and there's probably some type of spring in one leg and some type of damper in the other. That layout has worked really well for two or three decades now, depending on how you define 'really well,' and it's the recipe used by most of the traditional suspension manufacturers out there.

None of that is going to change anytime soon, of course. Sure, Trust, Structure, and Motion Ride are convincing some of us there are other ways to get the job done, but linkage forks will likely always be on the fringe. Interesting and always promising, but too bizarre for most of us to actually consider.

But Ashley Kalym didn't just consider one; he designed and built his own single-sided, carbon fiber linkage fork.

''I don’t have any engineering background at all, apart from teaching myself CAD over the last three or four years,'' Kalym told me, with the only other product that he's designed being a relatively simple archery release aid. Jumping straight into the deep end of the DIY pool, Kalym taught himself by using online resources and insists that what he's created could be built by anyone with the desire and stubbornness to get it done.
Ashley Kalym homemade linkage fork.
The 160mm-travel leading-link fork offers anti-dive and increasing trail, all from a single carbon leg and machined aluminum link that drives a rear shock.

There's surely lower hanging fruit than such an important, consequential component like a fork. ''I think that most other parts of a bike are pretty solid in terms of their function,'' he replied before admitting that there's little to no way for him to improve on a stem, handlebar, or other relatively straightforward parts. On top of that, the major brands focus their time and efforts on telescoping suspension, leaving plenty of room for the smaller outfits to experiment.

Kalym's focus was on the chassis, not the spring and damper, which greatly simplified the process. ''This meant that all I had to worry about were wheel path, leverage curve, and a few other bits and pieces,'' a process that took about two years of on and off work and ten different iterations before he decided on what you see here. Some of those were dual-sided, but the simpler single-leg layout won: ''Of course, this caused some packaging headaches, but I got there in the end. Also, going single-sided meant that I could increase the diameter of the fork leg to 50mm, and therefore increase the stiffness while keeping the overall weight the same as if it were two-sided."


Ashley Kalym homemade linkage fork.
Ashley Kalym homemade linkage fork.
A 20mm Hope Pro 4 hub works, as does a standard rear shock. Kalym was careful to only use existing parts.


If you've spent any time on Cannondale's single-sided Lefty, you already know that a fork doesn't require two legs to be torsionally rigid. The Lefty is a very different chassis, though, and its abilities come from a square (newer models are three-sided) stanchion that rolls in and out of the massive upper tube on strips of roller bearings. But Kalym wanted his fork to offer anti-dive abilities, and to increase trail as it goes into its travel to stabilize handling, neither of which are possible when using stanchion tubes. And he didn't want it to look horrendously complicated or require a one-off, non-standard hub, all of which led him towards the leading-link layout you see here.


Ashley Kalym homemade linkage fork.
What do you think: Is it better looking than a Trust, Motion Ride, or Structure, and should that even matter?


The benefits of increasing trail and anti-dive have been proven, with those traits creating handling that can't be matched by a telescoping fork, and Kalym admits to still learning what this means on the trail. ''It makes sense on paper to keep the head angle consistent and slacker when braking and cornering, but is that more beneficial than having the suspension completely free and active? I’m not sure yet, and there’s a lot more testing to be done,'' which is a rather refreshing attitude.

"The link itself moves through 47.16 degrees of rotation from full extension to bottom-out, which means that the brake caliper rotates around the disc a large amount, which equates to a lot of anti-dive.'' The trail grows from 130mm to 165mm at bottom-out, he says, which, ''equates to an offset of 45mm at rest, and 17mm at full compression.''

Kalym is working on a second version of the fork that will have a four-way adjustable floating brake arm to suss this out.




While the kinematics are still in the works, Kalym knew from the outset that he'd be using an off-the-shelf shock to handle the spring and damper duties. ''If you think about it, the rear of your bike is incredibly adjustable in terms of the shock choices you have. You can simply buy a new shock, bolt it on, and ride. You also have a choice of cheap or expensive, feature-poor or feature-rich, air or coil, and so on. However, if you want to change the spring and damper in your telescopic fork it’s a lot harder, and sometimes it’s not possible, especially if you want to go from air to coil and back again.''

So instead of thinking classic front suspension, Kalym wanted to design a chassis that could accept most shocks on the market. Prefer a simple air-sprung shock with a lockout lever? Not a problem. Want to bolt on an exotic coil-sprung shock from EXT, Push, or someone else? Go right ahead.

The rear suspension approach to front suspension also requires a progressive leverage curve to resist bottom-out, whereas a telescoping suspension fork is a straight 1:1 ratio. ''I was limited in what I could do because I went with a directly driven shock design, but I ended up with a curve that starts at 3:1 and ends at 2.54:1, which feels good even with a coil shock,'' he explained. An air-sprung shock would provide more ramp-up if that's what you're after.




The massive aluminum link pivots on 20mm x 32mm x 7mm bearings, there's a 20mm diameter axle through it all, and an M10 bolt holds it all together. ''It's pretty bombproof,'' Kalym told me, and it uses a normal Hope Pro 4 hub.

The massive upper leg was made by Carbonwasp, an outfit in Yorkshire that specializes in one-off, prototype carbon components. ''I’ve known Adrian for a little while, as I’ve done a few other 3D printed prototype things before doing the fork. He probably got sick of my emails, to be honest! But he was great in advising me the best way to go about certain things, and the way they do carbon made the whole project economically feasible." The single-sided leg was new to them, but Kalym says that the finished product is overbuilt and, "insanely stiff." Even so, he's planning to go with an aluminum leg for the next version as it'll make anti-dive adjustments and other modifications easier.

After a few year's worth of time and a hell of a lot of work, Kalym is ecstatic with how his fork performs: ''The sensitivity and activeness are like nothing else, much plusher than anything I’ve ridden. The amount of grip that the fork gives is really confidence-inspiring, and the increase in trail is noticeable (I think). Stiffness is also noticeable, with steering feeling much more precise and less delayed. I think the only thing that needs more exploration is the anti-dive."


Ashley Kalym homemade linkage fork.
Ashley Kalym with his homemade linkage fork.


There are no proper plans for a production version, though, with Kalym having been down that road before with the archery release aid. ''It just took the fun out of it for me,'' he said. ''If it grows organically then that would be awesome, but if it never happens I’ll be happy just to ride around on a fork that I designed and built. Obviously, something like this would be a niche product, and I think would be for people who are simply interested in performance above all else. There will be other forks that look better, weigh less, and cost less, but I’m certain there’d be a small group of people that would love to reap the benefits of a fork like this.''


409 Comments

  • 787 3
 Question is, will Oscar Pistorius be wanting it back when he gets out of prison?
  • 25 0
 LOL
  • 176 2
 He's in for a shock when he gets it back
  • 36 1
 #AngryUpvote
  • 9 32
flag Euskafreez (Feb 21, 2020 at 1:40) (Below Threshold)
 Will he -Pistorius- bounce back after his time?
  • 26 2
 @Euskafreez: He'll be firing on all cylinders.
  • 39 0
 The Pistonius would be a good name for it actually.
  • 3 23
flag BenPea (Feb 21, 2020 at 2:09) (Below Threshold)
 Oops, accidentally leaned on the downvote button. Wink
  • 11 2
 @Spark24: for forks sake
  • 5 6
 @MonkeyPuzzle: What about the O.S.K.A.R ? O.veractive S.uspension K.inetic A.rt R.eference
  • 41 0
 Hopefully not intended for ‘WC’ use
  • 4 0
 @Rocksled: LOL is an understatement. what a pull
  • 4 0
 Did not see that one coming...well played, sir
  • 14 0
 I am sure Oscar would love to take a shot at riding that fork!
  • 6 0
 This seems to be a one sided argument
  • 13 2
 "Oscarpistitus"
The fear of using the bathroom when your boyfriend is in the house.
  • 4 0
 @MonkeyPuzzle: because Pistolius goes too far?
  • 1 0
 hahahaha
  • 1 0
 Let's just hope that he's not 'armed' and legged when he gets out
  • 5 0
 That would be a killer combo
  • 2 0
 Thats actually the best comment in a while... Chapeau!
  • 5 1
 Some things are better left alone
  • 3 4
 Call me crazy, but for some reason, I Trust™ this Rocksled guy's Message©
  • 5 2
 Person gets/makes new suspension product - "It is the most plush best suspension I've ever ridden"

For Sale - One off Carbon single sided rear shock fork
"Hands down, the most plush best suspension I've ever used"

Reason for sale - "Upgrading"
  • 3 0
 I bet he’d love to give it a shot
  • 1 0
 HA!!! Got a good chuckle out of me.
  • 1 0
 Well done sir
  • 1 0
 Most clever comment I’ve seen on PB
  • 2 2
 Did you know that Oscar Pretorius wanted to paint the bathroom door, but his gf was dead set against it.
  • 212 1
 I don't know if this fork is for me but this approach to product development is 100% spot on. Kalym's refusal to require a proprietary hub, brake, or shock for this is truly inspiring.
  • 130 1
 Cheers Mike, that was actually the driving force behind it. I was seeing so many awesome shocks come out that I thought it might make sense to be able to use a normal shock on a fork. It's obviously not for everyone, but the function is very good, even if the aesthetics aren't.
  • 13 2
 @Rocksled: Nice work.
  • 52 0
 @Rocksled: Honestly this is the first of the linkage shock designs I'd actually consider buying. The functionality looks amazing, but IMO its also the best looking of the current linkage forks; the coil shock just looks too bad ass!
  • 12 0
 @Rocksled: Aesthetics is about the nature of beauty and taste. And I think telescopic forks are considered good taste because it's the norm in our culture (the MTB culture).
I think your design looks dope. I'm a believe of form folows function and, while telescopic forks do the job well, your design could be a better performer handling-wise and in maintainance. Ofcourse the shock has to be serviced just like forks but the shock can easily be swapped out for a serviced spare to minimize/eliminate down-time. And most importantly: no sliding bushes taking lateral forces. And three pivot points including shock mounts is not a lot! Keep it up!
  • 1 1
 @Rocksled Always been a fan of leading link suspension forks, when i first saw pictures of the Honda MX with it in MBA more than 30 years ago. This seemed to now materialize for mountainbikes. Hope V2 will make it soon(with Braking torque support). And what is really great about yours, is the massive mud clearance...
And then we can expect production?
  • 3 0
 @JorisW: Cheers! Yes simplicity was also a driving factor.
  • 9 0
 @mensch-mueller: Yep mud clearance is very good, although for British weather I need to do something about attaching a mud guard lol. Not sure about production yet, still lots of testing to be done, and a second version to be made, but if everything works and there is interest I'd love to see how far it can be taken.
  • 11 2
 When SRAM buys this idea and introduces us to the 19.9 mm proprietary hub...
  • 5 1
 @euan91m: Plus, KISS amirite? Aside from the shock there's like half a dozen components. Sick.
  • 3 1
 @Rocksled: honestly.. nice job.. i find it quite well done... i was never a big fan of the whole lefty design. I rode a few of them and always thought the feeling was nice.. but it is costly and time consuming when they don't work. I start to like the looks of these linkage forks though... Nice work on the fork and I would be glad to see someone like you getting a small business going out of this....I mean, if the Trust can sell, why not this???
  • 17 0
 man after the couple of linkage forks we've seen, this one makes the most sense!!!
  • 2 1
 @euan91m: I came here to say the same thing! Kudos @Rocksled !
  • 4 1
 @Rocksled was there any particular reason to not use a Lefty hub? They are available from a variety of manufacturers and the bigger bearings might be better suited for this kind of application? But anyway, awesome project!
  • 2 1
 @Rocksled: 'Attaching' a mud guard?! Just mold it into the carbon leg! Big Grin (Call it the British or PNW edition.)
  • 3 14
flag jorgeposada (Feb 21, 2020 at 9:05) (Below Threshold)
 Looking at that fork gave me diarrhea.
  • 2 1
 @Rocksled:

i think it's badass!

*full discolsure - previous Lefty owner here
  • 2 1
 @Rocksled: well call me intrigued. I’ve always been a sucker for a good linkage fork. #girvinit
  • 1 0
 @jorgeposada: well then u got bigger problems
  • 1 1
 Anyone who dares criticize this guys work can go fork themselves!
  • 1 0
 @blackthorne: Nah I flowin sweet but thanks for looking out.
  • 1 5
flag EuanBisset145 (Feb 23, 2020 at 11:29) (Below Threshold)
 I don’t think this is what Ashley says it is, I’m sure he has spent a lot of time modelling this fork. But I doubt it is even a properly rideable prototype or even carbon for that matter.

I believe what he has done is carbon wrap his plastic 3D printed model. It certainly looks that way. Happy to be proven wrong though.
  • 3 0
 @FR33DOMdotCOM: I never even thought of it to be honest; I just assumed they were unique to Lefty forks. I'm certain it would be better but I've got this wheel built up now so will use this for now! I'm experimenting with a two sided version which will be able too it larger body shocks and also have the adjustable anti dive, so for that I could use normal hubs.
  • 123 0
 Honestly, I'm just here for the comments lol. Seriously though, if anyone has any questions I'm happy to answer them. Ash
  • 6 0
 Have you done some big Hucks on your new fork yet?
  • 12 0
 Congratulations Ash, and thank you for pushing the envelope by yourself on this very boring industry. Trully remarkable.
  • 11 0
 @mkotowski1: No huge hucks yet, but it's bottomed a few times I'm sure. It feels a lot less flexy than other forks, but that's mainly the carbon thickness and amount of material, and the fact that the fork leg is a little more vertical than the head tube angle.
  • 6 0
 @joaovasco: Thanks buddy, although it is easier for a lone wolf like me to do something truly out there.
  • 2 1
 Is it possible to bleed the brake without taking the caliper off?
  • 1 0
 @Rocksled: that’s awesome man, super cool you’ve designed your own fork and now are actually shredding on it
  • 6 0
 @LaurensVR: Yeah it is. It bolts on just like any other front brake.
  • 6 0
 @mkotowski1: It does feel very cool. Although the best rides are the ones where I try and forget about the performance of the fork and just ride. Quite difficult to when trying to find faults and nitpick lol.
  • 3 0
 Congratulations. It's great to see another unique design and - as a bonus - no big company behind it. As I'm being a bit accustomed to aviation technologies, seeing such fork only rings a bell, but it's definitely not as shocking as it may be. Looks clever, your approach to design is smart and wise. I keep my thumbs up and hope you will develop it in the future to maybe a full product line?
  • 2 0
 @Rocksled: what about the weight?
Also I really like the way it looks man! Awesome design right there.
  • 25 1
 Why is it a lefty when could be a righty?
  • 4 0
 This is very impressive - kudos to you.

The article states you don’t have an engineering back ground - What do you do for a job/career? This would be an undertaking to say the least for someone trained in design!
  • 1 0
 @aljoburr: Coz we drive on the left, innit? Be weird to see an extension of the bike on the right.
  • 16 0
 @aljoburr: brake? I suppose you could just flip everything, but many calipers are not symmetrical and are designed to be mounted on the L side because that’s a standard.
  • 3 0
 @erikkellison: that makes more sense
  • 2 0
 @aljoburr: to compensate weight a bit (chainring, deraileur)? and cuz brake standard fitting is on left.
  • 4 0
 Hi Ash, I've been watching your project since a friend of mine let me know about your gallery here in PB like two years ago. I was very interesting to see your designs with your own comments. Let me congratulate you for what you've managed to achieve! Amazing effort and result. Hopefully, I will be one day able to show off my DYI fork, even though it's not going to be very soon.

Does you fork's chassis have fork crown and steerer tube as single monocoque? Have you calculated the change of front wheel offset throughout the travel? Your design would be very interesting to compare with Trust's forks.
Do you happen to know about Josh Gore from USA who built two prototypes very similiar to yours one? It's very interesting as well:
joshgoreworks.com/portfolio/funny-fork-ff-0102
  • 3 0
 Have you ever hit the bottom of the linkage when bottomed out in a deep rut?
  • 2 0
 @Rocksled When riding this thing, are you using a data acquisition system (shockwiz for air shocks or whatever works for your design) to get hard data or are you mainly going by feel?
  • 1 0
 So stocked you made it this far. Im such a big fan and I ve been watching you a long time. Are there more information about the shock ? What do you think of mine ? (Look up my pictures ) what cad program are you using ?
  • 1 0
 Looks mega, except the the aesthetic, I just can't get my head around the fork leg sitting behind the headtube, how come you didn't design it like the thrust with the fork in front and the wheel pivoting behind the fork leg?
  • 1 0
 @graeme187: I think this looks better than trust fork, but would be interested in trying both?
Hope this can be made cheaper!
  • 2 0
 @aljoburr: break calipers and some rotors can’t be flipped
  • 3 0
 @meathooker: Hi bud, I have been a writer for a long time, and before that in Personal Training and such. I did read a lot though about suspension design, and have poured over forums and videos etc., on the drawbacks of telescopic forks. It does take a bit of perseverance, and I think that was the main attribute needed!
  • 2 0
 @fluider: Yes I have heard fo Josh's project, and actually read all of his blog posts etc., on the development of hi fork.

Yes it is a single monocoque. Yes I have calculated the change. For a 63 degree head angle bike it goes from 45mm to 17mm, but for different head angled bikes it will be different.

Keep going with yours, looking forward to seeing it mate.
  • 1 0
 @bigburd: Not yet, although it's something I've got my eye on.
  • 3 0
 @bobthestapler: No nothing like that yet. Would be great to use one, but I know what the leverage curve is doing, and in real life it feels like it replicates what I see on paper. But, would be great to know for certain!
  • 2 0
 @emptybox: Cheers bud! I'm using a standard Marzocchi Bomber CR shock, 200lb spring, normal tune. I think there's lots of scope to do a custom tune, especially as there is a lighter spring, and there are no pedalling forces to counteract. I'll have a look at yours!
  • 2 0
 @graeme187: Yeah that is a consequence of the design and the layout of the pivots. I went with leading so that there would be natural anti dive. I believe trust's has some anti dive, but it is actually the result of the brake calliper rotating a little around the disc. I also think that heavy landings lead to less fore/aft flex with my layout, as the rider's weight is directed down through the leg.
  • 1 0
 @aljoburr: Cheers! I have never ridden the Trust fork but I hear lots of good things about it. If I get into production I'll try and keep it as reasonable as possible, but I think adding a shock in there will always make it a little more expensive.
  • 2 0
 @Caiokv: No idea of the weight, but it's not noticeable when riding. I'm certain it weighs more than a regular fork, even with the carbon fibre, but there is lots of material to be taken off of the link, and using an air shock would make it lighter.
  • 1 0
 @look-out: Cheers! Yes I'll see how things develop and if it goes well then I'd love to get it into production.
  • 1 0
 @LaurensVR: Yeah I think so, you may have to turn the bike upside down on this prototype.
  • 1 0
 @Rocksled: Have tried out a design similar to Structure Cycleworks linkage bike, but like your design too!
  • 1 0
 @Rocksled: Hi Ash, I'm a little late to the party but WOW what a cool design you have! Love everything about it. I'll echo what others have said above--I don't really go with the looks of other non-telecoping forks (Lauf, etc.) but somehow aesthetically your fork just works. I'd absolutely ride something like this on my own bike. I understand you speak of a tradeoff of a bit more weight for your increase in performance, but I feel like if you can get this down to anywhere near 3kg you're going to have a real winner! Best of luck, and again congrats on an amazing fork. Can't wait to see where you go with it.
  • 104 1
 I love these nutters.
  • 12 2
 I haven't had a nutter butter in ages....
  • 4 1
 @takeiteasyridehard: the old nut butt’s are far and few between
  • 42 1
 I guess I'll take that as a compliment haha
  • 71 11
 Whoever remembers Waki-leaks... I feel it is all obsolete now, and if I was ever to do it again, I need to take lots of mushrooms and acid quite often. The bar has been set really high. Sorry... there's nothing to criticize here, bravo, I honestly mean: bravo. Making it happen, making it work... holy crap that is impressive. If that was a conceptual sketch, I'd say get the hell out of here, but this is actually made and put into work... they don't call you crazy once you cross a certain threshold... so again: slow, loud clap!
  • 10 0
 Cheers buddy!
  • 8 1
 I just scrolled through a ton of your old Waki-Leaks stuff.... and I am now thoroughly convinced that you are a time-traveling wizard who is playing practical jokes on the internet.

You predicted: the E-Verb & eagle-tap, the CAD single crown lefty, linkage forks, the Grim Donut's headtube angle, DH bikes in wind tunnels, helmets with built in airbags, e-bikes (still waiting for front-wheel drive to come out), and more.

Whatever you do... please don't predict new wheel sizes or hub and BB standards... or else they will come true!!
  • 5 6
 @bikekrieg: nah, the only thing I predicted That wasn’t there was the single crown lefty. They still haven’t added the piggyback though.
  • 2 1
 lemme guess, you also designed mercs shapeshifter DAS for F1 car too? wouldn't be surprised.
  • 3 1
 @WAKIdesigns: That is exactly what a wizard would say.
  • 1 2
 @WAKIdesigns: @bikekrieg:

I'm hoping for a 603mm bsd rim - that's halfway between 29" (622mm) and 27.5 (584mm) rim diameters. 9.5mm change in rim radius.

No new forks needed, just a couple good rims and a handful of tires.
  • 4 4
 @getsomesy: I am much more into metric rims. 650mm and 700mm
  • 3 0
 @getsomesy: it's actually been done already it just never went mainstream. Before 27.5 hit the market some pros were on a custom 28" using cnc fork lowers to extend the legs and hand made tubular tyres on limited run rims. At least one major xc race was won on that.
  • 1 1
 @Riggbeck: Interesting, thanks for saying so!

I think it could be a good chassis modifier for a fairly low cost. I think there is a big enough gap to warrant an intermediary size. One could fine tune tire radial height (cushon) without having to compromise dynamic wheel radius. Just as we have many stem lengths, crank lengths, frame sizes etc; i think having the ability to fine tune one of the most important aspects of a bike would be truly beneficial.
  • 2 0
 @bikekrieg: Christini make a 2WD MTB.
  • 1 0
 @jrocksdh: dual axis steering for mtb? Change stem length and trail at the same time....
  • 1 0
 @iamamodel: so does Jeep
  • 54 0
 It's like a reverse Trust, the Deceit
  • 8 5
 If Orange made a fork...
  • 24 0
 Great work Kalym, brilliant product development. One of the best things about this is the "Im not sure yet" comment. May that approach continue throughout everything you do, we could all do with having that approach and no more so than the bike industry! Mega props
  • 19 0
 Cheers bud. I do have to make sure to keep my own BS in check lol
  • 1 0
 @Rocksled: He's too modest to say, but Findhan built a custom carbon MTB frame from scratch.
  • 9 0
 @excavator666: Haha I find that it's best to be modest, as there's always someone smarter than you.
  • 25 2
 I swear to god @mikelevy has a serious linkage fork fetish... Is that what happens when you get bored of riding all the superbikes? Wink
  • 3 0
 better that then "slug porn"
  • 4 1
 They're certainly more interesting than a lot of other things out there. They'll never catch on, though.
  • 1 0
 @mikelevy: I think you're right Mike; they're just too weird, and the aesthetics will always be a downer for a lot of people.
  • 14 0
 I think it looks better than the other linkage forks out there. I also like the single sided aspect which allows you to change tire without removing the wheel. If he ever makes one for the public I'd definitely be interested!
  • 5 0
 Cheers Sintra, although it's still a long way off. I should get the second prototype finished later this year, and then lots more testing to be done. I'd love to get a handful out to real world testers for real world feedback, but we'll see what happens.
  • 2 0
 @Rocksled: count me in!
  • 1 0
 @Rocksled: Happy to help out in any way I can too / southeast hardtail rider and love innovation!
  • 2 0
 @Rocksled: chunky terrain tester here in Arizona! Count me in for any help needed.
  • 3 0
 @Rocksled: I live in the French Alps and would be honoured to be a tester!
  • 1 0
 @Rocksled: I'm a sucker for having weird things attached to my bike, have a habit of breaking stuff and a tendency to heavily criticize forks so to pretend I'm a connaisseur. I guess I'd be perfect
  • 15 0
 Homemade linkage fork: yay. clipless pedals: sorcery.
  • 5 0
 Seems like a logical PB comment section answer.
  • 9 0
 Modern forks with SKF seals: "wow, this thing is so supple and responsive".

Convert to coil: "nothing matches the suppleness and responsiveness of coil."

Linkage fork: "sliding forks can never match the suppleness and responsiveness of linkage pivots."

Patiently waiting on magnets...
  • 3 0
 Makes me think of Cadillacs and magnetorheological (not a German word, believe it or not) fluids.
  • 1 0
 @ssteve: There's a video, not sure if you've seen it, of a Cadillac with that suspension, it's like voodoo or something the way it works.
  • 1 0
 @Rocksled: Was trying some tongue in cheek. I guess I've been living here too long.
But yeah I remember, basically based on road conditions a computer tells the fluid by way of electric current that the shocks should be more rigid sometimes and soft at other times.
  • 1 0
 @ssteve: yup GM actually
  • 1 0
 @Rocksled: Lexus with the Bose suspension ?
  • 9 0
 I guess I'm the only one concerned about using a 20mm thru-axle and standard hub for this. The reason cannondale uses that funky axle and proprietary hub is to keep the wheel snug and withstand the bending moment that is caused by having a single-sided fork leg. That 20mm through axle is going to fatigue fail, it's just a matter of when. And the left side wheel bearings are going to get destroyed from the extra load. I love the ingenuity but I wouldn't ride that with any confidence.
  • 2 0
 Yeah, the 20mm axle supported single shear is really sketchy. I hope he is at least using a steel axle. The lefty hub and axle are available.
  • 2 0
 @ThadQuinn: No the axle is aluminium, but there's 70mm of thread on the other side. I didn't skimp on the axle size and rigidity, put it that way. This is obviously something I'll keep an eye on as testing continues. It gets as much abuse as I can throw at it (when I have time to ride), but I understand the concern. And the wheel bearings are fine as far as I can tell, but lots more riding and testing before I can say for sure!
  • 8 0
 @Rocksled: The amount of thread on the other side has basically nothing to do with it. The bending stress at the left side of the axle is orders of magnitude higher than when in a typical fork, and you now have combined loading with the axle in bending, shear and tension due to the axle nut preload (If I'm understanding the stackup correctly, similar to a typical car spindle/axle nut), and all those loads are typically spread across the same cross sectional area when in a typical fork (among other differences). Aluminum is not only impossible to get to a higher strength than heat treated steel alloys (think 4340, but there's tons out there, and even 7075 Al won't get you close) and you can't ever design aluminum to have "infinite" fatigue life, so if you're close to yield on any hard hits, it's only a matter of time before it snaps and you go face first. This is not to criticize, because I support your effort and think that people just trying new experiments and prototypes is awesome, but there are a few key elements you may want to "properly" engineer just from a safety standpoint, and that's a big one. I could also guess that you could optimize the swingarm quite a bit to increase rigidity without adding much weight, just looking at the very open center section. There's probably someone out there who would be willing to do some free or cheap FEA just to get you some high-level input that might help prioritize changes in your re-design efforts. Hand calcs would get you a long way on the axle sizing, because you can easily baseline a normal fork that pretty much never will break an axle. Good luck! You clearly have the right attitude towards this project, and are ignoring the haters. Go for it!
  • 2 0
 Yeah, because fighter jet landing gear is always failing when 25 tons of metal lands at hundreds of mph

/s if you couldn't tell
  • 3 0
 I encourage you to check out how single sided airplane landing gear axles are designed. The cannondale lefty axle mimics this design.

The aluminum 20mm axle is unsafe, imo. If you got a solid steel axle turned, that would be slightly less likely to knock your teeth out.

The better solution would be to have an oversized, tapered axle, like the lefty.
@Rocksled:
  • 2 0
 Single sided landing gear uses oversized conical steel axles. So that the diameter is really big and strong where the wheel mounts in single shear. Not a small, alloy axle. The single sided lefty axle is based on this. @matt-15:
  • 1 0
 The lefty axle is 25mm on inside, 15mm on outside. And made of either steel or ti, not aluminum.
  • 1 0
 @dirt-klaud: not to mention the lever arm acting on that axle when you lean the bike over is a function of the radius of the wheel and the angle of lean. Rail a berm on that thing with some brake bumps and you’ve got a serious bending on that axle. If it were me, at a minimum I would swap that out for a high strength steel or Ti axle before doing any serious riding.
  • 3 0
 @dirt-klaud: Oh it needs FEA, and this is something that needs to be done before it ever went to production obviously. Going to steel for the axle would be a better idea from your input: would add weight, but that doesn't matter for this project, and there are plenty of people that don't count grams.

Edit: I've found a steel axle of the correct size so will order that for the time being.
  • 1 0
 @bentplate: It feels totally rigid in this riding scenario, but I guess it can never be too safe. Ordered a steel axle to see the difference. Then when funds/time allow will get some FEA done by someone in the know.
  • 1 0
 @Rocksled: 20mm axles are thought for dual sided operation. Going steel would mitigate the risk but you should go either oversized custom hub or lefty conical hub. Most single sided sided system use conical fitting for a reason. Lefty hub are widely available and the hassle of buidling a front wheel is not much for someone considering such a wild design.
  • 3 0
 @Rocksled: Hopefully you don't see the difference Big Grin . I doubt you'll be able to sense a difference since the aluminum is probably rigid enough as is. The concern with aluminum is that it always has a finite fatigue life, regardless of the stress. With steel, as long as you are below the fatigue strength, it has infinite fatigue life. You can also get way stronger steel than you can get out of aluminum. Aluminum is also more notch sensitive than steel so those threads are going to be more susceptible to failure. I'd probably also loctite that sucker in there so it doesn't loosen on you at the worst possible time.

Honestly, I don't think you need FEA done on that part of it. Some pretty straight forward hand calcs will get you a good idea of where you need to be since you're not really worried about weight savings or eeking out the last bit of stiffness. FEA on the chassis and the linkage may be a good idea at some point, or just keep it beefy AF!
  • 1 0
 Cranks, pedals, handlebars and stems are only supported on one side as well. So are pretty much all vehicle wheels except for the wheels on bikes. My intuition says that a straight aluminum axle is fine from a strength standpoint. It could certainly be made lighter though with a tapered design.
  • 2 0
 @bentplate: Cheers! I have been playing around again trying to get the brake mount and everything else packaged on the left hand side, and have mocked up a two sided version with the shock on the right and the brake stuff on the left. Obviously this would also help mitigate the axle and hub concerns, but it would also add another CNC part, 2 more bearings, etc. Still lots of iteration to go until version 2!
  • 1 0
 @dfiler: Yeah that was my initial thought too, and there is a tonne of force going through pedals and cranks at any one time. But, it can't hurt to test these things and make sure it is ultra safe, especially in a vital area like the front wheel.
  • 1 1
 @dfiler: I hear you, but those were all engineered to be single sided. That's different than taking an axle and hub that were designed to be supported on two sides and taking away half the support. It may be fine, but my intuition is that when you change something from double shear to single shear+bending you need to be damn sure it's strong enough. Bending is what breaks things.
  • 1 0
 Take your examples of handlebars and crank spindles. Find a bike handle bar or bb spindle that’s 20mm and aluminum. There are none. If’s it’s in the 19-22mm range, it’s gonna be made out of steel. If it’s aluminum, it’s gonna be at least 25mm, more likely 30+mm. @bentplate:
  • 6 0
 @Rocksled: This is great and I can see a following developing for the fork. My only concern would be ground clearance. It seems to drop very low especially when compressed. That is an advantage with the standard fork that compression does not result in a drop in the ground clearance and therefore more risk of rock strikes and damage. Are you finding this an issue on the bike?
  • 5 0
 Yeah that was a concern. I haven't hit anything yet, although only 15 or so hours on the fork. I guess if you were traversing a very narrow trail with high sides there might be an increased risk, but for normal riding it might not be too bad. The mech hangs down lower and I haven't ever hit that on anything, but that is at the rear, so who knows? It's something I'm keeping an eye on though.
  • 1 0
 @Rocksled: Thanks. I’ll be watching with interest. Best of luck!
  • 9 0
 Hats off to Ashley Kalym and Pinkbike for giving him a well-earned spotlight.
  • 6 0
 Cheers buddy, yes Mike reached out personally, was a very enjoyable exchange.
  • 13 0
 @Rocksled: Too much information
  • 6 0
 Say what you want, but this dude is a legend. Regardless of how it works this dude did it. Instead of complaining on the internet he made something. “The man in the arena” and all that.
  • 1 0
 Haha thanks bud, you guys are swelling my head with all this talk.
  • 6 0
 Hats off @Rocksled. Been following this on Insta and I'm super impressed. It's bloody hard getting stuff made. Following with interest.
  • 4 0
 Cheers buddy, thanks for the follow!
  • 4 1
 I think this is awesome. I actually really like the looks of it too! I don't know how to fully explain it, but I think other linkage forks I've seen look too crazy while I'd be happy to bolt this one on my bike. Hire a manager to take care of the production stuff one day, that way you can focus on the fun of designing this thing and we can all buy one!
  • 2 0
 Thanks bud, I've gotten used to it now, but it was very strange at first.I'll get version 2 out of the way and we'll see about production. If there is enough interest then I'd love to do it.
  • 1 0
 @Rocksled: impressive stuff
  • 4 0
 Now we have single pivot forks and four bar forks. Seriously though, this is aestheticly much better than the trust fork and I like the one-sided design with a standard shock.
  • 1 0
 Cheers man.
  • 2 0
 Brilliant. and it incredibly, it looks to be at a production point you could sell, for actual money. no shonky prototype/mule about it at all!

An issue i see (constructive criticism): to make the pivot stiff enough, that lower linkage is WIDE. is that not the widest point of the bike (off the centre line) by some margin? I suppose pedals stick out further actually, but i would be concerned dropping it into deeper ruts and gullies, especially considering your wheel is going to want to sit in the middle of a rut, effectively doubling the actual width of the fork?
  • 1 0
 Not sure about production ready yet! But towards the end of the year perhaps. Yes the fork leg is 50mm, so with the link it's 74mm. I haven't' hit anything yet, but it's definitely a concern. I'll keep an eye on it and if it does start hitting stuff then it might be back to the drawing board!
  • 5 0
 I am inspired to get my it-will-never-work project off the shelf after reading this. So imressive.
  • 4 1
 Cheers bud, just go for it. Worst that can happen is it doesn't work out the first time.
  • 1 0
 Do it! Doooo it. Do it do it do it do it. DO IT!
  • 2 0
 Lots of work, very big effort, would love to try it, but no production models planned is kinda sad. The market is skinny for this kinda of product, Trust may be able to make it, but another linkage fork company just went under so it’s to be seen if mountain biking can make the shift that moto has not.
  • 4 0
 If the interest is there I'll try to get it into production. This is only prototype one so early days yet.
  • 2 0
 Which linkage fork company just went under?
  • 1 0
 @Insectoid: motion ride makers of e18.
  • 1 0
 @reverend27: Yes, I noticed that their site has shown their forks as being out of stock for around two months. Are you sure they're gone, or are you concluding that because of the site?
  • 1 0
 @reverend27: I wrote to them and they claim they have forks in stock. So they seem to be in business.
  • 2 0
 This is the approach to linkage front suspension I want to see developed further. Yessss, allowing us to choose which currently available shock for our front suspension is exactly what we want! With some refinement, I think the aesthetic is appealing, maybe even more than the Trust fork. Definitely looks better than Structure and Motion Rides offerings in my opinion.
  • 6 1
 That's really cool Smile And it looks much nicer that SCW 1
  • 3 0
 Cheers bud, although looks are subjective of course. It looks less weird the longer I look at it, but that's true with everything I guess.
  • 1 0
 @Rocksled: Everything different tends to look weird at first, but somethings it looks cool and some are just hideous.

Your fork is compatible with standard parts and that's why you gonna win this one Wink
  • 4 0
 "What do you think: Is it better looking than a Trust, Motion Ride, or Structure, and should that even matter?" Yes and yes.
  • 1 0
 Cheers bud
  • 3 1
 From all the current linkage forks that is the one I could definitely be happy to bolt on my bike. I saw it a few weeks back on IG, happy to see it here now I will keep an eye on this for sure Smile
  • 2 0
 Cheers buddy, thanks for the support!
  • 3 1
 Amazing story. This is classic British engineering and this dude should be very proud of himself. I wish I had the knowledge/talent/drive/ability to achieve something like that.
  • 2 0
 Cheers buddy. I'm confident most people have the know how, just takes some time to understand what areas of knowledge are important for something like this.
  • 5 0
 Where does the water bottle go?
  • 1 0
 I think this would be brilliant for older riders like me who desire comfort and compliance. Older guys might not mind paying more for a hand saving fork . Even if it’s twice the cost of a regular fork , it would turn out cheaper than doctor visits and carpal tunnel surgeries . Older riders also might look past any visual differences when they don’t feel pounded after a ride. I ride in CT and there are lots of older riders ( 40 plus)
  • 1 0
 Yeah it's definitely comfortable. I still think it allows control though, as your wheel is in contact with the ground more as a result.
  • 2 0
 Nice work Ashley, reminds me so much of my speedway days and the motor bikes I used to fabricate. I would rock one of these if only for nostalgic sake. Keep up the great work.
  • 2 0
 Cheers, buddy. Yeah I've seen older motocross bikes, sidecar bikes, and some trikes with a similar thing, though just double sided instead of lefty.
  • 1 0
 I called it when I was talking to a few of my friends a while back, we'd get a lefty linkage fork within the year. Interesting idea, I wonder how it rides! I want to know how the coil interacts with chatter and bumps vs something air sprung.
  • 2 0
 The coil is really good, very active. I haven't tried it with an air shock yet, but if I can get hold of one that is the correct size I will do. Actually, finding a spring light enough was the real challenge, as especially with these longer bikes there is a lot less weight on the front wheel. I'm running a 200lb nukeproof spring, which seems to be perfect, but I don't know anyone else that does one lighter, or as light. Air would be a better choice for adjustability though.
  • 1 0
 Have you tried the fork in a steeper headtube situation? With the trail increasing further into the travel, it might be nice to get away from the disadvantages of a slack head tube while still having the wheel far enough in front on your steepest roll.
  • 3 0
 So I designed the fork around a 63 degree head tube angle, so for steeper head angles the trail increase will be less, and for slacker head angles the trail increase will be greater. I think a future version (if I get there) would benefit from having adjustable shock mounting positions to cater for different head angles.
  • 1 0
 I’m so impressed! You did it! I feel good taking care of my suspension, not building it. Not that my opinion should matter to you, but I love it. It’s ugly, it’s heavy and it’s yours! Good job man. You should be proud.
  • 1 0
 Cheers man, yes it's definitely heavier, but it works better in my opinion.
  • 1 0
 No idea if this is legit or not, but a place called "Adroit" has a single-sided carbon linkage fork on their website... for actual sale (although out of stock)... www.adroitcycleworks.com/product/adroit-single-sided-linkage-fork
  • 1 0
 I've tried emailing them multiple times with no response...not sure
  • 1 0
 @RadBartTaylor: I haven't emailed, because I'm not currently in the market to buy anything other than a helmet. But ya, something is strange. Everything is out of stock, but yet, they have some strikingly up-to-the-minute geometries on their hardtails, and actual photos of actual bikes. Maybe just some rich guy's vanity project, doesn't actually want to sell anything - just make cool stuff for his own use and write off a loss on a business or something ;-)
  • 1 0
 Outstanding. I suggest making it a dual crown like a lefty, that way you could lower your axle to crown height by not having such a thick single crown. Probably gain even more stiffness. I prefer this design to all the professional linkage forks PB has reviewed recently.
  • 1 0
 I did think that, but the second version has a much lower crown height, and more material within the steerer to do away with the star nut/expander bung, and also to allow 29er wheel to be used as well. Cheers!
  • 1 0
 Ashley, man:

That linkage fork is simply stunning Next-Next-Next level DIY engineering. Everything about the design and part sourcing. Total package. Wowser!

Tip o' the cap, and then some, my friend! : )

[Full disclosure: I have a Trust Shout on my main whip, and I love it!]
  • 1 0
 Cheers buddy! It took a while to come together obviously, but very much worth it.
  • 1 0
 Looks like a lot as the front suspension of an old small 50cc motorcycle from Piaggio called Ciao. Although that was traditional with two stanchions, seems like nothing new under the MTB sun, still learning from the motorized two-wheels industry
  • 1 0
 that is amazing that someone did something like that DIY! Very cool...

It does look like a big hit/landing/Gout where there are rocks that are close the the left side of the wheel could be an issue? Normal forks get scraped up, loose a cap now and then on the end of the fork, but that at least is a fixed drop.
  • 1 0
 I love the innovation and the diy work ethic!

Random thought I had to address the lower link clearance issue:

This is hard to explain. What if you set it up so that the lower link as oriented like a swing arm, with the axle positioned at the back?

Picture a mirror image of what you made. Then adjust crown angle, shock angle, and linkage path to accomplish the same objectives you achieved. This would place the link in the front and above the axle, or mostly above. It would significantly increase ground clearance on that side.
  • 1 0
 Inspiring stuff. A very well refined package for a home made fork!
How well do the hope bearings do under the single sided loading? Looks like quite a large bending moment around the left hand bearing?
  • 3 0
 They seem to run well so far, but obviously still lots of riding and testing to be done to see how they hold up. The fork probably has around 10-15 hours riding time on it so far, so lots more hours needed to make a conclusion.
  • 4 0
 I have so many questions.. . .. but I'm afraid to ask them. .. .. .
  • 2 1
 Ask away buddy.
  • 4 0
 Get this guy a job at Cannondale stat!
  • 4 0
 @Rocksled -- how much did you spend on the fork? Just curious...
  • 4 1
 Not a fortune. Actually it was less than another linkage fork that's on the market now, but obviously it took up a tonne of time and so on. I also only got one unit of each of the CNC parts, and that's expensive obviously. I also chose a fairly budget shock in the Marzocchi CR, but it works well enough to test it.
  • 3 0
 @Rocksled: Kudos to you for trying. Ignore the naysayers
  • 2 0
 I'm absolutely down with all of this, the idea, development and result. Not something I'd buy, yet, but sweet project none the less. Cheers
  • 1 0
 Cheers bud!
  • 1 0
 The biggest thing on my mind is the linkage hitting stuff at bottom out. On a regular fork the actual fork legs never go below the axle height, but here it+s gonna go significantly lower than that.
  • 1 0
 I'm keeping an eye on it that's for sure.
  • 1 0
 Depending on where you live this could either be a deal breaker or no issue at all. Where I'm at, there are enough rocks and logs that it could be an issue. Though without trying it out, i'm only speculating. Derailers hang low and seem to survive despite being more fragile than this fork.
  • 1 0
 Telescopic fork is the best !!! These stupid designs!! Lol when the fork is compressed , that huge chunk of lower fork leg is just dangling down there. ready to catch a root , rock , or whatever and spit you off your bike
  • 3 2
 Cool, looks like a USE SUB but it is nice to be able to use different shocks.

Wondering though, do you need to remove the brake caliper when taking out a wheel?
  • 1 1
 No, just lift the wheel up.
  • 1 0
 @tomhoward379: Ah, so the axle slides out of the dropout? That makes sense. My mind was in the "Lefty" mode with the tapered axle. I actually haven't looked into how they do this now with the PM fitting but I recall with the IS brake mount they used to use slotted mounts and required the brake caliper attached at 9Nm. Which appeared scary to me as the brake caliper was typically limited to 6Nm. So when out on the trail (typically without a torque wrench) when fitting the wheel (for instance after a puncture) you know you need go well beyond the 6Nm but not too far beyond 9Nm. Fail either way and either the caliper could break or release from the fork. But yeah, that was the old Lefty. Not an issue with this one.
  • 3 1
 Great. If possible, a straight rocker arm, with an higher upper shock mount, would allow for some 5cm more ground clearance.
  • 2 0
 I did try many different variations, but this was the only one that could work with a progressive ratio and packaging. That was the major headache; packaging.
  • 1 1
 that the first thing i saw, it feels scary to me!
  • 1 0
 @Tasso75 That was my thought too. Straight rocker arm at same angle as chainstay could be more aesthetically pleasing, and lower weight?
  • 2 0
 As this design is kind of "single pivot" as opposed to other link forks parallelogram types. Was braking effect considered?
  • 2 0
 Or is it not a concern (sorry for the p.s)
  • 3 0
 @nojzilla: Yes it is a single pivot effectively, where the link drives the shock directly. Brake dive is very strong on this version, as the brake calliper sits on the link. Version 2 will have adjustable anti dive.
  • 2 0
 @Rocksled: Yeah, I noticed the "floating caliper" design in the picture about version 2. Do you feel the anti-dive is too extreme on the "single pivot" kind of design? I can imagine the downside of anti-dive is that the suspension becomes too inactive when braking though of course fair enough with a progressive spring you'll lose some activeness too as the fork lowers in the travel. So yeah I see both sides of the story and I'm just curious whether you came with this floating caliper design because you felt the need for it or just to experiment.

Either way, of course props for making this happen!
  • 1 0
 @Rocksled: was something like ABP or a floating hub axle considered? sorry for asking .I'm a fan of those types of desighn on rear suss so was wondering about it on the front now with linkage forks becoming a thing Smile
  • 1 1
 @vinay: ah, just noticed that. my question answered
  • 1 0
 @Rocksled: you can adjust anti dive by adjusting your pivot position relative to the wheel.
Higher pivot or shorter arm will both reduce dive.
  • 3 0
 @vinay: I think it probably is too strong on this version, but I did it this way to keep the first version simple.

It actually rewards very aggressive riding, and being over the front wheel a lot. The suspension actually stays very active when braking, just that if the front is unweighted it wants to extend the spring, depending on how hard you are braking. Without getting too technical, the brake calliper on this one goes through nearly 50 degrees of rotation, which equates to a lot of anti dive. Version 2 will have four settings, going from 0, 10, 20, and 30 degrees of rotation, which should give enough adjustment to suit most riding styles. Although testing will confirm this.
  • 1 0
 @Rocksled: This was immediately my question! How predictable is that interaction of braking and suspension, esp. in rough terrain? Dows it feel strange if you come from a classic fork?
  • 1 0
 @Rocksled: Alright, cool. I think it is nice to have the option to play between zero or a lot of anti-dive. Just like rear suspension designers do, you now also have the option to have multiple shock mounts so that you can play with the progression of the same shock. Or even have the option to do so on the fly. And as you are in the position to build the fork which ever way you see fit, you can even shift the hub off center so that you can enjoy equal spoke length (and tension) both sides. The possibilities are limitless and it will take you a lifetime to experiment with all you can do with it. Enjoy!
  • 1 0
 @Rocksled: Thank you for answering this. However, doesn't this mean that your anti-dive is very strong? When I saw this post I was thinking of the Greeves motorcycle forks. I'm designing a linkage fork basically for your same reasons, but mine will have multiple pivots to control the instant center for the purpose of having less than +100% anti-dive. I'd suggest getting a hold of Tony Foale's "Funny Front End" FFE analysis software. It runs on Windows and it is super handy.
  • 2 0
 @yoobee: Sorry just seen your question! It feels different from a normal fork for sure, but not so different that it doesn't feel like suspension, if that make sense. I think also that I am much more aware of what is going on because I am trying to feel what is going on, instead of just riding my bike. It feels predictable, yes. I feel much faster on this fork than before, although only the stopwatch would confirm this.
  • 1 0
 @RegularCyclesLLC: Yes it is very strong on this version, although not so strong that it is unridable or anything. It will be interesting to see how it rides with no anti-dive a la a normal telescopic fork, and then to gradually increase the amount to see what the difference is. Yes I have heard of that program, it might be worth getting it!
  • 1 0
 @vinay: I will do! It has been lots of fun trying to figure things out, and riding something that you designed is a cool feeling, no doubt.
  • 2 1
 Reminds me of the ELF 500GP bikes of the 90s. Linkage should be trailing rather than leading like the other forks out there.
  • 1 1
 I've not seen those, I'll have to check them out. I did see the Britten bike though which piqued my interest..
  • 1 0
 That Elf was insane. So interesting!
  • 2 1
 Well this is not even ugly, matches really well with the industrial look of a nicolai.. and the philosophy is good to use stardard shocks. Great job!
  • 2 1
 Agreed. Call me crazy, but some sense of aesthetics is important.
  • 1 0
 @Adamrideshisbike: It's the truth, although most will never understand.
  • 1 0
 Can you fit a 1.5" star fangled nut in the bottom of the fork steerer tube I may have a Mudguard for you! I think the work you have done here is outstanding!
  • 1 0
 You could with this version, but for the next the steerer walls are going to be much thicker (idea suggested to me by Paul Aston via Instagram) to do away with the star nut/expander bung and to make the whole area stronger and stiffer. I'll have to work something for he mudguard out as even with goggles my face gets plastered in the UK.
  • 3 0
 Hears my home made linkage fork!
www.pinkbike.com/photo/17994253
  • 3 0
 Is it truly a linkage fork if it's just a single pivot? Single Pivot Fork
  • 3 1
 You're not wrong buddy. I'll call it the SPF.
  • 3 1
 @rocksled Well done dude. Thats damn impressive. Way to do something no one has done before!!
  • 1 0
 @Rocksled Quite nonplussed you post this without giving us a video showing it compressing! Seriously, it would help appreciate this fork in all its glory.
  • 3 1
 Sorry, there is a video on Insta, but not sure if I can link here. If you search for @rocksled_suspension you'll see the video. I should be getting a GoPro soon enough to get lots of footage.
  • 2 0
 How do you make sure there is no air in the brake if the caliper is upside down and the bleed nipple is at the bottom?
  • 4 2
 Lol good point. Turn the bike upside down I guess? I haven't bled the brake with it on yet.
  • 5 2
 imagine building this, then cutting the head tube too short...
  • 3 1
 This fork is infinitely better looking than that trust POS. Great job Rocksled!
  • 1 1
 So basically he had an extra frame lying around. Decided to cut the top tube off the frame keep the rear shock and modify the rocker link. Voila. You now have an oddly looking one sided fork.
  • 2 0
 Nice to see innovation on an individual level. Where is the ride video? Cheers to the effort.
  • 1 0
 I have yet to get my hands on a GoPro, but there's some video on my Insta.
  • 2 0
 Agree @bentplate Don’t know why he didn’t use a lefty super max hub. You need a cantilever hub
  • 1 0
 I really like the look of the fork and would love to see a cheaper Alu one. The choice of shocks makes it the most versatile (not yet) on the market.
  • 1 0
 Looks great tbh, is it possible to have it on two sides just using a lighter build but increase stiffness? Keep the the shock on one side ofc.
  • 1 0
 When did Single Pivot become a linkage??
Also need a few more moving parts, throw in a handful of acronyms, then he can call it a linkage!
  • 1 0
 You're right, it is a single pivot fork. New category needed!
  • 4 1
 ¯\_(ツ)_/¯
  • 2 1
 Seems like that design would be prone to some pretty nasty rock strikes on full compression!
  • 1 1
 Yeah that's what I was worried about, but nothing so far. The trails I ride aren't the narrowest or the rockiest out there, but it's certainly an issue I'm keeping an eye on.
  • 3 1
 Love the looks! Fantastic job.
  • 3 1
 Cheers! It looks as good as I could make it look with my zero experience in product design!
  • 2 1
 I'll wait for the single, right sided fork with an entirely floating left sided brake caliper.
  • 3 1
 How close to the ground does that linkage get under full compression?
  • 2 1
 Not sure in mm, but the picture I've linked shows what the fork looks like at full compression.

www.pinkbike.com/photo/18107898
  • 1 0
 @Rocksled: that's awesome, I was expecting it to drop down more. Do you find that lower elbow takes a lot of abuse?
  • 1 0
 @Kiotae: Not yet, but I've only got 15-20 hours on the fork so far. It's something I'll keep an eye on testing progresses!
  • 1 0
 I would like to see the distance between the linkage and the floor when its fully compressed. It can be scary..
  • 1 1
 See above somewhere, but this picture I think www.pinkbike.com/photo/18107898
  • 3 1
 Will this fork work in the grim donut? Asking for a friend
  • 1 0
 Could this approach be adapted to mimic the kinematics and axle-path of Structure's Cycleworks SCW 1 using linkages?
  • 1 2
 I guess it could, might have to go to some sort of four bar set-up or something, as on this the wheel path is an arc described by the swingarm.
  • 2 1
 Cheers for the ingenuity and DIY. Still want to kill it with fire before it lays eggs tho.
  • 2 0
 Didn’t know I’d ever have to worry about ground clearance for my fork
  • 2 1
 LOL, technically correct.
  • 1 1
 DYI from some passionate rider looks much better then any other manufactured linkage forks that were presented on this website; kudos to him, i would buy this stuff
  • 1 0
 I like it! It looks promising. I do however, have a concern about the clearance when going through a nasty rock garden.
  • 2 0
 I like. I'd love to try one.
  • 1 0
 Much better looking than the Trust forks or the Motion Ride! I would hit that!
  • 2 0
 Love it, keep up the innovation...I'd love one of these!
  • 2 0
 Do you need testers?? this would look amazing on my calling!!!
  • 1 0
 Hope he has a patent on that bad boy. If not I'm stealing it... its THAT good!
  • 1 0
 I barely had time to design this with two young kids! So applying for a patent is out of the question lol
  • 1 0
 Piaggio called they want their Vespa fork back.

(Good to see someone finally put this idea in practice in a MTB)
  • 1 0
 I actually think that fork would work better if the linkage was the other way around.
  • 1 0
 It possibly would for increasing trail I think, although in this configuration (without anti dive adjustment) you'd get very strong pro dive.
  • 1 0
 Man, I love the idea of being able to match the rear shock to the front. I would be all over this fork. Kickstarter this!
  • 1 0
 Exactly buddy! Now if only I could afford an EXT for the front and back...
  • 2 0
 DIY projects, love them! Thanks for inspiration! Wink
  • 1 3
 If it had a face it could get a job at the bakery pushing said face into the dough to make the gorilla biscuits (read cookies, all y'all North Americans).
I'm sure it has a grest personality though.
  • 1 0
 Gorilla Biscuits, great band!
  • 2 1
 Blade runner, is what it reminds me of.
  • 3 0
 Reminds me of a sword from the first Soul Edge game. No escape from the nineties, I suppose...
  • 2 2
 It would actually look alright if there was a leg on the other side. Then it would be.... a fork
  • 3 1
 Looks like a USE
  • 2 1
 Good one you, looks awesome!
  • 2 1
 Great job my friend. Keep up the hard work.
  • 2 0
 Cheers!
  • 3 2
 holy shit, i love this thing. great work.
  • 2 1
 Cheers Bruccio!
  • 1 1
 @Rocksled: cheers to you mate!
  • 3 2
 Put it on the grim donut please ????
  • 2 0
 Haha yes.
  • 2 1
 This is rad, good stuff Ashley.
  • 1 0
 Cheers buddy
  • 1 0
 Awesome work, guess fitting a mudguard is a nightmare!
  • 1 0
 Haha, I tried and failed, so version 2 will need to incorporate some way to attach an off the shelf one.
  • 1 0
 @Rocksled: can you not use an expanding bung in the bottom of a steerer and fasten one there maybe
  • 1 0
 Internal routing of the brake line for the next one?
  • 1 0
 It's possible, but I'm not sure if it might just be extra hassle when it comes to bleed, remove the brake, etc. It's definitely something I'd consider though.
  • 1 1
 nice concept you can choose the shock you want and it works with a classic 20mm hub .
  • 1 0
 It looks like a Cannondale
  • 2 0
 Nicely done!!!
  • 1 1
 It'd be cool if he built a frame next so that crown-headtube intersection doesn't look broken.
  • 1 0
 are you guys trying to tease charlie out of retirement?
  • 2 0
 What’s it weigh?
  • 1 0
 No idea, but more than a normal fork easily, and probably more than a dual crown, especially with a coil shock.
  • 1 0
 This Guy shall love cybertruck
  • 1 0
 The rocks and roots will smash the low leg
  • 1 0
 Not yet, but I'm watching out for it.
  • 1 0
 Any videos of it in action?
  • 2 1
 Haha, great.
  • 1 1
 Still better than a Lefty
  • 1 1
 www.gov.uk/apply-for-a-patent ...if you haven't already!
  • 3 1
 I did think about it ages ago, but there's nothing really to patent, plus for a single person like me I don't think it would be worth the effort. My time is probably better spent designing the next iteration.
  • 3 0
 @Rocksled: This is the open-source mentality. Pretty awesome to see in "hardware" as opposed to just software.
  • 1 0
 @mattjolley: I'm also not sure how much it costs, but it's certainly more than the money I have just laying around lol.
  • 1 0
 @Rocksled: you could literally patent “the main pivot is lower than the axle, for use on a bicycle fork”
  • 2 1
 we want grim donut
  • 2 1
 The fuck.png
  • 1 1
 Canondale engineers just nutted
  • 1 1
 Take my eyes but not the fork!
  • 1 1
 I'm disappointed. Why can't someone make a righty.
  • 1 1
 cannondale are now iring him for a prototype lefty
  • 1 0
 Its a fork and a shock!
  • 1 1
 Like a wise man once said: just nope me out of here!
  • 1 0
 Top work boy.
  • 1 1
 yes. no. I mean...I dont know... but just look at that....
  • 1 0
 H-ooooooooly J----s!!!!
  • 1 0
 Has the bottom of that swing arm ever hit anything? I’d imagine there’s not a lot of clearance when it’s fully bottomed out.
  • 1 0
 @JikkityJek: Not as yet, but I've said in another comment that it's something that I'm keeping an eye on. Packaging has been the major issue with this whole project, and how to get everything in there without any part of the shock hitting anything else!
  • 2 0
 @Rocksled: This is a pretty cool project man. I wish I could do something like that but I don’t have the time, the skill, or the money. Good luck!
  • 4 5
 Hmm...Can we have a linkage fork filter please?
  • 1 1
 new nike shoe?
  • 1 2
 So, what is next? Fork with bluetooth and usb charger?
  • 4 6
 Put it on a Marin Wolf Ridge and you'll get the ugliest 2 wheeled thing that stands below the sun!
  • 3 0
 LOL
  • 1 0
 And I think this is the prettiest linkage fork out there.
  • 3 6
 The thing that saddens me is that it is mounted on a NICOLAI Frown
But my question is:
Why don't some people devote themselves more to auto eroticism?
  • 4 1
 Hey, what's wrong with Nicolai?!
  • 1 11
flag pk71 (Feb 21, 2020 at 9:53) (Below Threshold)
 @Rocksled: I have a Nicolai G16!
and it's the best bike I could ask for, I'm sorry to see one with an abortion like that ......
  • 1 1
 Looks like a Session
  • 1 3
 I think Im going to vomit everything I have now
  • 2 4
 yyyyyyyyy tho
  • 8 0
 Why not is a better question!
  • 1 0
 @Rocksled: see fork picture above.
  • 1 4
 The fork we don't want or deserve?
  • 5 8
 STOP IT, NOW !
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