2020 Husky Enduro Range: R&D Insights
R&D Project Leader for Husqvarna Motorcycles’ enduro models, Florian Schober, offers an insight into the standout developments that appear on the Austrian brand’s new-generation 2020 models.
TM: As always, Husqvarna’s design team articulates a design philosophy for the range. For these 2020 enduro models, it was “agility, rideability, and comfort”. Notably, no mention of weight savings or improved performance…
FS: We are already one of the lightest bikes on the market, and performance is inherent in everything we do. Improving agility, rideability and comfort might sound like only refinements, but we have effectively redesigned more than half of the bike. Which is not an easy task. More than 60% of the 2020 bikes’ parts are new.
Let’s start with the skeleton: the frame. Its architecture is the same, but about 50% of the tubing is different, right?
Yes, that is right. So visually, the frame may not look much different. But we put a lot of work into optimising its stress points and flex characteristics. That means adding or taking away material in very specific areas or changing welding lines.
This is the first time in the past eight years that Husqvarna (and KTM) has not increased the flex of its chromoly frame. Why the change this year, with the frame being made stiffer – both longitudinally and torsionally?
When we talk about the frame, you are right; this is a new way of thinking for the 2020 bikes. We reworked so many parts that influence handling and comfort, that we now have more freedom to play with the frame rigidity. You know, handling is always dependent on the interaction and distribution of designed component flex. And for our 2020 bikes, we have generated – on an entire vehicle level – a big improvement by stiffening the frame and transferring the flex to other parts.
The 2020 WP suspension package has also seen significant changes.
It has. The WP XPLOR fork has a softer spring and firmer damping, and an all-new spring preload adjuster and internals. And the WP XACT shock gets a different linkage and completely different settings to suit that. You could say that those changes to the fork represent a new set-up philosophy. After much testing, we found that the softer spring and additional compression damping helps the fork ride higher in its stroke, which gives the chassis a more balanced feel. There are also some big internal changes to the fork to improve the consistency of its performance. Our focus with the shock absorber was to minimise the impact that it has on the fork.
Explain how you achieved that with the shock absorber.
Well, we use a 3mm longer pull-rods and a slightly adjusted triangular lever in the 2020 linkage, which means it’s now the same as our motocross bikes’ linkage. That makes the rear-end of the 2020 bikes a little lower and the steering head angle 0.7 of a degree more raked out. And by making that geometry change, a given force through the upper shock mount now transfers much less energy to the bike’s front-end and fork. And as an added benefit, the new linkage lowers the seat height, which makes the bike easier for the rider to control in extreme conditions.
“Visually, the frame may not look much different. But we put a lot of work into optimising its stress points and flex characteristics.”
And for the first time ever, the subframe has been specifically engineered to flex a little and ‘help’ the shock’s action, right?
Yes, the carbon fibre reinforced polyamide subframe is now lighter and, as you say, designed to flex. This is so it can assist the shock absorber for better rider comfort. We have been using this subframe material in our motocross models since 2017, so we have a lot of data about its strength and flex character. That experience told us that we could simplify the subframe assembly by using two pieces, not three. And by controlling the stiffness and flex where we want it, we found that we can improve the feel of the entire bike for the rider. In addition, we managed to get the subframe and main frame to work more harmoniously when it comes to how they flex.
Which is unlike your 2016 models, whose super-stiff subframe – and the two-bolt mounts on either side – actually ‘bound up’ the main frame and stopped it from flexing in the way it was designed to.
Exactly. Different mounts and more material flex helps with shock damping and allows some movement between frame and subframe. It’s actually very difficult to simulate the flex of the frame and subframe and understand how they work together, so this has to be done by extensive rider testing. We tried many different versions before we settled on the design for the production bikes.
The 2020 bodywork is all-new and makes a big difference to the feel of the bikes. What was your primary objective for the ‘rider interface’, as you like to refer to it?
Again, it’s about controllability and comfort. The new seat is about 10mm lower at the front and 20-22mm lower at the rear, without compromising comfort. It was even possible for us to increase the foam thickness. Combined with the slimmer bodywork through the rear-end, that gives the rider more control in extreme terrain. It’s easier to get your feet on the ground, and to move further back on the bike for big obstacles or steep downhills. This improves both agility and rideability.
“We did a lot of work with the combustion and increasing the compression ratio of all the engines, and I think the biggest advancements we’ve made for 2020 is how well the bikes perform at lower RPM.”
Arguably, the changes to the 2020 engines weren’t as significant as other mods this year. But what would you say has been the biggest area of improvement with the new bikes’ power delivery?
We did a lot of work with the combustion and increasing the compression ratio of all the engines, and I think the biggest advancements we’ve made for 2020 is how well the bikes perform at lower RPM. Obviously, there are many engine changes that complement each other – and, as always, mapping plays a big role in that – but reducing flame-outs at low RPM is a clear improvement this year. Our EFI guys put in an enormous effort to make sure that the software harmonises with the updated hardware in the 2020 engines.
The airboxes on the 2020 Husqvanas and their equivalent KTM models are a little different, so does that mean the two brands’ mapping is also different?
No, the maps we use in each model are the same as the orange bikes – mainly because it takes thousands of man-hours to get the maps perfect for each capacity model. It’s true that the different airboxes create a different airflow, which means there will be a subtle variation in the way the bikes deliver their power. Also, with the ambient air pressure sensor, we introduced to the two-stroke TPI models for 2020, the fuelling is much better at adjusting in ‘real-time’ to any changes in parameters. And this makes it a lot more refined.
As the R&D Project Leader, how you do make a call on the final production bike’s settings when development is an ongoing process?
Often with difficulty [laughs] because our test riders are always enthusiastic about discovering improvements and making changes. These guys are incredibly sensitive and find every potential for improvement on the bikes. However, the time comes when no changes are possible. Basically, at this point, we have already talked about fine-tuning for Pro-rider level. I also need to bear in mind that we also have technical accessories for riders to customise the bike the way they want it – for sandy or muddy/wet conditions, for example, or for hard enduro or cross-country applications.
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