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Updated: Norco Factory Team is Testing a Prototype High-Pivot DH Bike

prototype norco downhill bike alloy frame 6-bar linkage spotted canadian national championships 2023
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Update: The original version of this post speculated that the Norco frame in question runs a 6-bar linkage which, strictly speaking, is incorrect. This was our misunderstanding, and we thank DHDave for forcing us to rethink this one. It is actually a four-bar linkage that defines the rear axle path in this prototype frame, with an additional two links and very short yoke working to drive the rear shock. That said, we won’t have a full understanding of the prototype Norco DH bike until we have seen how all the bars rotate as the rear end is pushed through its travel, and have more detailed information from Norco.

Gracey Hemstreet, Lucas Cruz and Mark Wallace have been testing an all-new prototype aluminum downhill bike from Norco. And, Lucas Cruz just won the Canadian Downhill National Champs aboard his. Here’s what we’ve gleaned so far.

Norco’s Prototype High-Pivot DH Bike

prototype norco downhill bike aluminum frame with telemetry
Happily, a trip to the Norco website yielded a host of detailed studio images of the prototype downhill bike, dressed up with telemetry. Credit: Norco.

Until now, Gracey Hemstreet, Lucas Cruz and Mark Wallace have been piloting the Norco Range DH at UCI Downhill World Series events, which is essentially a long-travel version of the Range Enduro Bike, adapted for the demanding tracks with a dual-crown fork, and a modified link in the rear to allow the frame to accept a longer stroke shock. Now, it seems, the team is to benefit from a dedicated downhill bike that runs an all-new suspension design.

norco dh bike prototype four-bar linkage design drive side view
It is possible this dropout design could allow the team to play around with different rear-center lengths; indeed, the letters “RC.4” suggest there are at least four possible lengths. Also note the heavily-machined construction of the seat stays.

Bidding farewell to the linkage-driven single-pivot of the Aurum HSP, the new Norco sees a four-bar linkage which appears to be a modification of that we see implemented on the Norco Range. The latter sees the lower link articulate about a pivot concentric to the bottom bracket, and connected to a secondary link that serves only to drive the shock.

In contrast to that, the lower link on this aluminum prototype (light blue) is pivotally connected to the front triangle at a position above, and slightly aft of, the bottom bracket. Between it and the rear shock, there are two links working together (pink and orange) to drive a very short yoke (dark blue), which is the final member involved in driving the rear shock.

norco dh prototype rough schematic of four-bar linkage layout new high pivot suspension platform
Image annotated by Cory Benson – Bikerumor.

We reached out to Norco for comment on the new linkage design. Richard Belson of the Norco Communications Team said, “The new DH prototype uses a complete re-imagining of the High Virtual Pivot suspension design we introduced on the Range a couple years back – but optimized for DH racing. Custom linkages and suspension components allow fine-tuning of leverage curves and allow us nearly infinite control over every aspect of the suspension performance. The principal design goal was to give the Norco Factory Team the best equipment available to win races on and provide engineers with and unprecedented level of control over kinematics and fine-tuning every aspect of the suspension”.

Indeed, Norco is sticking with a high-pivot, seemingly very happy with the majority rearward axle path it delivers. An idler pulley looks to be positioned concentric to the upper pivot in order to route the chain in such a way as to reduce the negative effects of chain growth that would otherwise impinge upon the performance of this layout.

norco prototype downhill bike 4-bar high pivot linkage 22tooth idler pulley

The team are running a 22T idler pulley, which is very large by current industry standards. Only the Nicolai Nucleon 16 with the Lal Bikes Supre Drive runs an idler pulley this big; the larger circumference of the pulley reduces the articulation required at each link, and thus the friction in the system.

norco prototype downhill bike 4-bar linkage flip-chip upper shock mount
A flip-chip at the upper shock mount will allow for some adjustment.

I shan’t be commenting on what kind of kinematic is likely to arise from such a layout, but it seems to work nicely with both air and coil shocks. Lucas Cruz just won the Canadian National Champs aboard this prototype Norco DH bike, sprung by a RockShox air shock running a very, very large air can – as compared to the modestly-sized air can we see on the Super Deluxe Ultimate Air Shocks, that is. Meanwhile, 2nd place Mark Wallace‘s bike was coil-sprung.

Also noteworthy is that a Norco Development Engineer involved in the creation of this bike, Kirk McDowall, filled third place on that same podium. Chapeau.

prototype norco downhill bike alloy frame 4-bar linkage spotted canadian national championships 2023
We are informed the new Norco DH prototype is designed around a 29”/27.5” configuration.

Richard tells us Norco have a solid plan to continue development of this aluminum prototype to meet the needs of the team. He goes on to say, “Everything we learn with these frames and this development process will inform future versions of our most popular platforms, but our primary goal is to create the fastest DH bike in the world, with no expense spared. There’s still a great deal of work to do before determining what version of this platform ever makes it to market, and when”.

The snippets of information we’ve collated from the Norco Factory Team’s social media indicate that the team will be switching to this new bike for the rest of the UCI Downhill World Series, kicking off in Pal Arinsal, Andorra, on the 24th August.

Until then!

Norco.com

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nooner
nooner
9 months ago

Balfa called, they want their high pivot back.

blablabla
blablabla
9 months ago

How is it a “high-pivot susp.”, when the lower bearing and it’s link (which make the ‘center’ of the rotation) are right next to the BB?

blablabla
blablabla
9 months ago
Reply to  blablabla

OK, nvm. Sorry, missed the hard-mount of the top point to the frame.

DHDave
DHDave
9 months ago

Jessie-May and Cory, it’s a four-bar design.

Bar one is the mainframe (purple), bar two is the seastay (green), bar three is the chainstay (yellow), and bar four is the link between the chainstay and mainframe (light blue).

While there are another two links coming into play to then go on and drive the shock (orange and pink), taking them away would have no effect on the axle path.

The orange link is concentric to the seatstay to mainframe pivot, so doesn’t play a role in dictating the axle path. It is a link, so to speak, but it’s unfortunately not a bar in the system.

Andrea rearte
Andrea rearte
8 months ago
Reply to  DHDave

I dont think these distinctions make sense for newer generation downhill bikes. 4-bar is used to differentiate an axle path which has 2 pivots between the axle and the front triangle in any direction, from a single pivot axle path with any kind of multi link shock actuation. In today’s DH bikes the shock actuation seems to become just as important as axle path (or the separation of it). so calling it a 4-bar doesn’t do this justice.

Anyhow: what does a 6-bar frame have to look like to be called a true 6-bar? even the Pivot prototype frame has the axle path directed by 4 links (not counting any flex-joint, as i can’t tell where the flex happens). 3 pivots in any direction doesn’t work. the axle path would become an axle plane.

Last edited 8 months ago by Andrea rearte
Martin A Navarre
Martin A Navarre
9 months ago

How about making the idler float in the sense it’s on a linkage? The BB is fixed, but the idler can move with the rear wheel … I’m envisioning the idler on a shuttle like the Yeti Switch Infinity. The chaingrowth there is managed by an tensioner. I’m thinking of the 2 separate chains design – a chain between the chainring and idler and a separate chain from a second idler to the cassette. Even somehow these 2 idlers could be independent somehow.

As I understand this Norco design – it’s a single pivot – the green link. The other stuff is just driving the shock.

Spencermon
Spencermon
9 months ago

There are patents on idlers that are mounted to moving suspension components. Mounting the idler concentric with a pulley or mounting the idler to the frame avoids these patents. I-Track has the patent and seems like they would like to get paid to license it to manufacturers.

manny
manny
9 months ago

very beautiful and very nice drive train

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