Trenavix Stealth Bomber Gen3

[Trenavix]

I did share a peek of this in the general bombers thread, but felt like I should make a thread for it at some point.
Here are Gen1 & Gen2 on an old site of mine.
What I've done since I've moved back to the states from Finland a couple years ago, is combine these two bikes into the best they can be as one.
The KTM EXC front-end is too big and heavy for the bomber frame, ended up cracking it around the head tube area, thus I stuck with the DNM-USD8 as it is much lighter.
I swapped the QS273 stator for a very high Kv one I had in a closet, that can potentially hit 140km/h with a fully charged battery, no field weakening.

The battery on Gen2 was an IED built by UPP that I tried to improve with updated lead wiring (2AWG) and an ANT BMS, but still, some cells were fried by then and it was just a terrible idea to have 400 cells in a single pack. They were good cells though, Samsung 35E's.
My bikes were in Cali, and I moved to Washington shortly after returning to Cali. I gutted Gen2, and stuffed its parts in the backseats of my car, and had Gen1 intact on a hitch on the back.

Gen1 was usable, and I fitted 2 72v "cargo packs" into parallel for it to be used.. Said cargo packs were meant for Gen2's pannier bags, but Gen1 needed some battery for a bit.

After getting settled in Washington, I ripped apart the 400 cell battery pack and tested all cells for the ones with best IRs (after a bit of charging on all individually).

I found that, if not grinding the sides off of the bomber frame (after Gen2, I recommend NOT grinding sides off - it hurts stability), I could fit a maximum of 360 cells in the frame if going with 20s. Which is 18p.

Many months of slow work and eventually I built it. 3 sub-packs wired in series with external BMS on top. Everything fit exactly as planned, and was definitely a hard cram.

I then used the cargo packs exactly as planned, in panniers. Altogether, the bike is 20s28p, 7kWh.
It can push a maximum peak of 364A (almost 28kW with voltage sag)

October 2023, I registered my motorcycle. I rode it to Washington State Patrol in Marysville, and they did a VIN inspection, and granted my bomber a VIN plate. I could then take it to the DOL and it was granted a plate, after I showed all my part invoices. Insurance through SafeCo is $92/year.

I have 39000km on the odometer as of posting, 21.5k of those km are in the past year, with the new battery setup. I frequently ride into Canada on my motorcycle, sometimes into the Cascades, off-roading frequently, and almost every single 60km work commute from Edmonds to SODO (Seattle) is on it.

I also had some issues with water ingress on my qs273. I have had to replace the halls a few times now due to rust on the rotor magnets.
After some lurking in threads here, I found that insulating varnish could prevent the rust and keep it going for many years, so a couple weeks ago, I coated both the stator and a new rotor in EL600. Hope it plays out well.

I'll post some important pictures below.
Some other eventual upgrades were:
-Kickstand: Directly tapped into the swing-arm, closer to the pivot point
-Dual front-brake callipers (I hand-crafted the second adapter mount for the DNM forks from aluminium),
-Reinforced steel plate on the swing arm for the shock's force (custom welded)
-New pannier bags (2x batteries fit in one bag, my large 3kW charger fits in the other bag)
-Reinforced steel cargo bag brackets, custom made
-Heated grips via 12v splice (Needed for Washington winters)
-Reverse switch wired to "engine start" button (hold the button and throttle, wheel goes backward)
-Better handlebars (slightly raised, more like dirtbike)












1 Single Cargo Pack:

 

[Trenavix]

Yesterday I did an acceleration test.

I think you could manage a 0-100kph closer to 5.5s if you are braver on throttle in the 0-50kph section. I was just scared of wheelying while exiting the kinda shitty shoulder I was in.
This is also on the highest Kv motor I have (140kph top with load with near full charge) with 600 phase amps.
While I could use my slightly lower Kv motor (125kph), I think the bottleneck is wheelying lol.

Even in this test my front wheel left the ground about a cm in the 40kph area (felt it touch the ground at a slight turn, you can even see it in the video). Fairly short wheel base and bike is only 100kg or so.

 

[MaxBicycleMax]

@Leon525

 

[Trenavix]

I did a video walk-around of the bike some months ago and forgot to share.

I don't think I've changed anything on it since then. Odometer is now at 46468km and I commute to work 4 days a week on it... the varnished motor has held up incredibly well over salted snowy/sleeted roads in winter - have not needed to take it apart at all.

Edit: Actually I changed a couple things:
-I installed a stiffer coil into the DNM front forks which was a major improvement for front suspension
-I replaced the damping oil in the front forks (small improvement, hard to tell against the new coil)
-I welded in more steel to the cargo rack so it doesn't sag anymore from the weight (just a thick piece of sheet steel from bar to bar)
-I further waterproofed some of the exterior wiring using JB Weld plastic bonder on the back of the connectors to the combo wire outer insulation - not even salt water will affect signal wires now

 

[Trenavix]

Been a while since the last update - does anybody know what happens when the ct-22 dash hits 99999.9km?

I recently re-built+trued my rear hub motor wheel into a new rim, since the old rim had a small bend in the wall, to make it roll smoother (it was fairly vibratey at around 100kph)

After getting the wheel back in, the hall sensors were dead. I opened up the motor and found cracked phase wires on my 2T stator.

I replaced the sensors and tried to patch up any cracks but they died after a couple rides again - I think the wires are cracked even inside the combo wire and are killing the sensors via the wires getting crossed. So my 2T is out of service for now... not sure if I want to put in the work to re-wire everything since I may be moving in some months. I believe the cracking is due to high heat, and QS Motors using cheap PVC insulated wires. Running silicone wires would fix this issue (and maybe slightly higher gauge)

For the time being, I am using my 2.5T, which reduces my top speed from around 135kph down to 120kph. I went ahead and varnish coated the 2.5T before putting it in so it's also waterproofed.

That varnish really did hold up - I found zero signs of rust inside the motor despite it having water in it. I found what seemed to be a very small deposit of minerals, since water would enter and evaporate out of the motor. It didn't seem to be salt (which was my first guess), but it didn't do any harm to the varnish.

Last week out of curiosity I did a LOT of research on what battery cells are available these days, as my 35E's are definitely putting in a lot of work for how old they are (6 years!). I made a master spreadsheet for cell information, particularly focusing on volumetric energy density since motorcycles really need it. The green portion is cells not yet released. What I found is that with the absolute newest cells being 6-6.5ah, you could fit a LOT more energy in a stealth bomber these days. Inside the frame you can fit up to 21s16p of 21700's, which on 6.5ah, means 7.86kWh. (20s16p shown here)

If you combine that with a cargo battery like I do now, we are talking around 11kWh on a bomber, with maybe a 130kg weight.

I personally am not going to be building anything for some time as I am planning to move back to Europe to study electrical engineering, but I am closely watching where the tech is going so that I can plan a future project. My biggest ponder lately is how to get DCFC going, which will likely require a very high voltage setup with an Orion BMS.