Home > Other Fun Stuff > Prototypes & Concepts

Motion’s 120mm Leading-Linkage XC Fork Could Hit the World Cup in 2025

motion engineering 120mm xc fork prototype leading linkage kona hei hei cr eurobike 2023
13 Comments
Support us! Bikerumor may earn a small commission from affiliate links in this article. Learn More

Motion Engineering, better known for their wild-looking E18 180mm travel leaf-sprung fork, are working away on a very lightweight 120mm travel leading-linkage fork that relies upon a standard rear shock for damping. At Eurobike, the 3D printed prototype was fitted to a Kona Hei Hei CR. We got the details on Motion’s this futuristic XC fork from Mechanical Engineer, Finan Levingston.

motion engineering 120mm travel leading linkage mtb fork lightweight half crown design

Motion Engineering’s 120mm Leading-Linkage Fork

Motion’s 120mm XC fork, the 3D printed model of which you see here, is 1.5 years in the making. The project stems from the company’s belief that cross-country mountain bike forks can be way lighter, and way more simple, than the ubiquitous telescopic forks we see on the market, and on the race tracks, today.

On this basic prototype, an air shock mounted almost vertically behind that DT Swiss branded cover, is driven from below by a rocker. At the base of the fork, on the non-drive side, you’ll see what looks to be two rockers. The top one drives the shock, while the lower rocker serves to prevent braking forces from forcing compression or extension of the shock.

Indeed, this design aims to overcome this drawback of a common telescoping design wherein front wheel braking can force the fork into compression, something that is often referred to as fork dive. With the brake caliper mounted to the lower rocker, or torque arm, those forces are isolated from the suspension’s action, such that it neither has a tendency to dive, or rise, when the rider grabs the front brake.

That matters on the trail, because if braking is robbing you of early-stroke travel, there is less stroke available to absorb actual bumps you might encounter. And, when you do hit a bump while braking, the fork has moved deeper into its travel where more force is required for compression. If the Motion XC fork can stay high in its travel under braking, then it stands to reason that it will maintain more of its small bump sensitivity with more travel in reserve.

And, this one’s a half-crown design. This goes a long way to bringing down the fork’s overall weight. This was one of Motion’s top priorities; they wanted to make an XC fork that is lighter than the Rockshox SID Ultimate, which is currently one of the (but not the) lightest 120mm travel mountain bike forks money can buy. That weighs around 1,300 grams, while Motion Engineering’s equivalent leading-linkage design weighs a claimed 1,200 grams – we’re waiting to hear back on which shock that uses.

The fork leg, if you will, will be a monocoque carbon design, with a carbon steerer tube molded as part of the same structure.

Motion Engineering’s aim is to work closely with brands to develop a fork as part of their frames. Indeed, the plan is for this 120mm travel offering to be an OEM component only, and thus not available aftermarket. Motion will offer brands the opportunity to tune the fork’s linkage to their needs, giving them more control over how the frame works in conjunction with the behavior of the front end of the bike.

Mechanical Engineer, Finan Levingston, tells us that the Motion fork will exhibit much less friction than a modern telescoping fork, thus conferring improved small bump sensitivity. And of course, compression of the shock is controlled via a linkage, so tuneable progression can be engineered into the linkage, just as brands do for a frame linkage.

The 3D printed fork on display at Eurobike is one of Motion’s more basic designs, but a poster on the wall at their booth depicts a number of possible iterations of the leading-linkage design.

We’ll keep in touch with the folks at Motion Engineering to keep you guys updated on developments as and when they come. Finan was very vague about it, but did mention the possibility of bikes rolling out of stores with a design very similar to this one as early as May 2024.

What about Motion Engineering’s World Cup Racing Ambitions?

Finan was careful not to mention any brand names here, but he did say that we can look forward to seeing Motion’s 120mm travel leading-linkage fork on World Cup XC Race Bikes in 2025.

motion-engineering.fr

Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

13 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Exodux
1 year ago

As far as linkage forks go, this is definitely the cleanest design I’ve seen. Will it work and make telescoping forks obsolete, time will tell. I think it will work just fine, but existing telescoping fork manufacturers shouldn’t worry.

Zach
Zach
1 year ago

Brake caliper Is definitely exposed at the lowest point of fork there

Raouligan
Raouligan
1 year ago

Going to be honest designs doesn’t looks polished as the USE SUB Anti Dive fork from 2002

JNH
JNH
1 year ago
Reply to  Raouligan

It’s very strange that nobody has ever tried to refine the SUB, it was such a good fork at the time.

Raouligan
Raouligan
1 year ago
Reply to  JNH

Yeah it does although most people I knew with them had them apart more than they had them together, easy to service as well at least…

Harry Farq
Harry Farq
1 year ago

It’s just called a leading link fork they’ve been used on motorcycles for over half a century.

Roger Pedacter
Roger Pedacter
1 year ago

With the axle concentric with the pivot, it’s not actually a linkage fork. It’s a swingarm, with the able path being a basic arc. The upper link only looks to isolate brake inputs.

Charlie S.
Charlie S.
1 year ago
Reply to  Roger Pedacter

You can’t be sure without detailed schematics. If the upper link changes anything about the path of the axle, then it is a linkage. But point taken- the Axle is not on the link between the two arms…

Pfs
Pfs
1 year ago

You can go single sided or weird but not both. Source: been putting lefty’s and lauf forks in bikes for years

Tim
Tim
1 year ago

The original Motion Ride fork had 140, 150 or 160mm of travel, not 180 as stated in the article.

Oliver
Oliver
1 year ago

This is disappointing 🙁 – “the plan is for this 120mm travel offering to be an OEM component only, and thus not available aftermarket”

I reckon they could make a gravel version not much heavier than Lauf’s fork too. Maybe ~900g.

Last edited 1 year ago by Oliver
E X
E X
1 year ago
Reply to  Oliver

Agreed, if they don’t sell this aftermarket they are going to miss a significant opportunity. I would be surprised if any mainstream brand picks this up for a serious oem XC bike. But tons more people would buy it aftermarket I think.

Clay
Clay
1 year ago
Reply to  E X

Complete specutation but before you worry about market share you have to worry about initial R&D and tooling cost to produce a product. My guess, this this path gives them greater access to up front capital. Basically, sign an exclusivity deal with a couple manufactuers for a cash infusion to get the product up and running.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.