Building Lightfighter v2.0
Updated: Oct 14, 2020
The term "Version 2" or "v2" got thrown around a lot in our first season - basically a catch-all phrase for all the improvements we would make if we ever had the chance to start over. At what point it became a commitment, I'm unsure. I'm pretty sure that Troy gets some of the blame though for convincing us to follow-through.
This build began in the winter months of 2019 and stretched into the first 6 months of 2020 amidst a global pandemic and multiple natural disasters brought on by global warming. The challenges were significant, but we were undeterred in bringing this bike to life. It helped that Ely is almost completely self-sufficient in his capabilities at his shop in Ashland, Oregon, where the bike came to life.
While we had several smaller goals for v2, the big ones were:
New component layout to facilitate trackside battery installation and removal
Increased gear ratio (shorter gearing) inside the MGU
Raise the MGU by 25mm to improve clearances at full lean
Decreased lateral stiffness main chassis
Increased stiffness/lighter weight seat subframe over the plastic Kramer seat/tank unit
Increased battery capacity with latest, greatest Lithium-NMC cells from Farasis Energy
Integrate all the 12Vdc electronics into the battery - i.e. DC-DC converter, etc...
We had initially hoped to keep version 1 of the bike intact, but it quickly became apparent that harvesting some of the components from it would have a big impact on the schedule of getting version 2 completed. So... Thanks for the memories, v1... you were a good race bike.
Fabricating the new main tubular chassis was the first order of business. I'm skipping the hundreds of hours of iterations and CAD work that got us to this point, but when it was time to cut and cope tubes together, the frame went together pretty quickly. The frame is constructed of chromoly tubing with very short "hip plates" that hold swingarm pivot. The shape of the frame was modified to reduce the cross section dropping down to the MGU and pivot in an effort to gain some lateral (side-to-side) flex and compliance as well as allow the battery to be removed from dropping it down and out the side of the bike. More on that later. We went with a black frame last season, but wanted to really highlight the change this year, and we already knew we were losing the flo neon wheels, so House of Kolors "Honey Neon" was selected for the frame. Along with being designer and fabricator, Ely was also the painter!
While we were in the off-season, Troy got in contact with a company in Germany called Thyssenkrupp (yep - they also make elevators) who were anxious to get a set of their ultra lightweight carbon fiber wheels into his hands for evaluation and exposure in the US market. Troy mentioned our little project and we ended with a couple sets of these beauties... besides their amazing build quality, they are also the lightest wheel I've ever had the opportunity to hold. They were lighter than the (already light) OZ forged magnesium wheels we ran in 2019 by roughly a pound each.
Speaking of carbon fiber, it was also my goal to design a new stiffer seat subframe for the new bike and for help with that, I turned to Paul Taylor of Taylormade Racing. After some discussion about options, I opted to have a 3D printed (actually FDM) part made that Paul could then use as a master model for taking carbon molds and eventually the real part. The full process took somewhere close to 3 months, but I'm quite happy with the result! The wing elements are left over from a previous automotive project and adapted nicely to my vision of a "club-level" implementation of the aerodynamic devices popping up on MotoGP and production superbikes these days. The rear wing elements also provide a nice clean surface for sponsor logos!
While the motor remained unchanged, the internal gear ratio change required new endplates and gearcovers. The phase leads were also re-routed out the top of the motor, removing them from their precarious position on the bottom of the motor last year.
The battery received a complete redesign and received a new set of cells from Farasis Energy, which boosted capacity by about 15% vs. 2019. The additional capacity should help support the higher power levels of the new bike as well as provide for another lap or two at race pace. The new battery also integrated the main contactor, DC-DC converter, and smaller relays into the top, making the whole system simpler and safer to work on. Win-win!
If you remember from the start of this post, another big goal for the battery and the frame was to make battery removal simpler. While we haven't yet completed a battery swap at an event, it's certainly come in and out of the chassis several times, and it looks promising that when we get a second pack completed, it'll be possible to swap it with the bike up on front and rear wheel stands and a small scissor jack under the battery.
Once the battery is lowered, it'll clear the bike from moving out the right side as both inlet and outlet coolant runs are on the left. There is the main quick release DC connection on top of the battery and a 12-pin Deutsche connector to disconnect, along with 4xM8 fasteners in order to fully disconnect the battery. My expectation, although yet to be proven out, is that a battery swap could be performed in about 5 minutes with two people, and about 10 minutes if it's just you. Still, a "recharge" time of 5-10 minutes is a massive improvement compared to the 1-1.5 hours it would take to recharge from a 220V/50A circuit!
With the exception of the custom carbon fiber tail section, the front fender, and the carbon fiber side plates, the rest of the bodywork are provided by our friends at Kramer Motorcycles. They are the identical parts to their super cool, super fast HKR EVO2 track bike. Not wanting this bike to look like "just another gas bike" out on the track, we opted to go for a Britten V1000 inspired half-fairing look with the side plates and wing elements taking the place of a traditional side fairing and the bellypan being significantly trimmed down and minimal.
When it came to the livery design for the bike, we looked at a few different options, finally settling on the one that was the "loudest". No room for the timid when it comes to racing...
The bodywork was painted here in Santa Cruz at a local autobody shop, while the frame was painted up in Ashland, Oregon. The vinyl work was done by yours truly.
Skipping over a lot more electrical wiring, fitting of the bodywork, and long nights... the bike finally rolled out of Ely's shop ready to begin its long journey to getting sorted out on track in testing to become race worthy...