Working on a single 6374 190kv build got room for about 40 cells. Rider (tha’s me) approximately 200lb. Focbox. 15/40 or 15/36 gearing I think.
Here’s what I think. 12s3p is out because 36 cells. Leaning strongly toward 13s. I think it’ll be more versatile than 10s.
But of course if it pops it’ll be a bad day so I’ll try to gear it for torque/brakes and not speed. Well, not so much…
Wadda ya guys think?
I think you are going to run into the limiting factor of torque transfer on a single setup running 13s.
Aka, running belts the way you should, you won’t really be tapping into that power without belt slip. Belt slip on single 12s is even not insignificant in my experience.
On a single, I would just do a more mild build and run 10s.
The mount is really stiff and has idlers.
Let’s see, there are a few things I’m willing to try.
I’m trying to save weight on this build. Tried 12s with a 5065 200kv, and that was not satisfying, not even close, and hot hot hot motor. Maybe single motor is not meant to be, but ah I’ll give it one more shot.
10S4P all day
Yeah the single motor will just be a bottle neck for all that power
13s if you are using a 60a discharge BMS. 10s if you are bypassing the BMS or using an 80a+ BMS.
Consider chains, no tooth skip
You may have issues with traction. Consider kegels, much wider than flywheels
Would that extra 8mm really do that much? (Boa Constrictor vs Evolve 107)
Wrong thread? But the usable wheel sizes are like 83,90,97,100,107. There’s a noticeable difference in torque and top speed between all those sizes. Plus as you go up the wheel gets heavier.
Back to my topic. thanks guys for your input, all voting against my plan hehe. It gives me second thoughts, as in what will I do with my pack if 13s3p sucks? So I started thinking how to build the pack so I’m not committed to 13s3p.
Then I remembered I have NESE 4p hardware lying around, and a double stack @NAF deck. So I can build the pack using NESE or perhaps @Winfly’s no-solder pack system, modified to fit the HYPERBEAST deck if needed, and try 13s3p. I have another 10s4p pack I can compare it against.
If 1x6374 sucks for my use, I can abandon the idea entirely.
im sorry I wasnt being clear who I was responding to. I was talking to @Jmding about wheel contact pitch, and if it would improve traction at 13s or not 
my bad
usually single motor 6374(with that gearing) is enough to get anyone (lighter) going in terms of top speed and torque… anything else isnt fun x)
Aaaah wow it’s 8mm difference? Hmmmmmm.
yep! boa is 63mm and evolve is 55mm
Hmmm! But, it must be so much heavier if it’s that much wider…
Again back to me:
Can’t find weight, but clones are around 300g
https://boawheels.com/products/hatchling-90mm-wheel?variant=11148676137003
Can’t find weight
So Boa is like huuuge wide.
But 25% coupon at Boa, and 90mm OOS? 
I’m not sure how you plan to ride this board but for me I think you might find some benefit to 13s3p even on single drive. I’ve been riding a single 6374 for almost a year every single day. In my opinion although you will have problems getting the energy to the road you may still want that extra top end and possibly slightly lower temperatures from the voltage on single drive. Just because a single can’t accelerate quickly doesn’t mean you can’t go 30-35mph lol. Though you may not be able to do that with just a 6374 and a 3P battery at 200lbs. Also as far as wheels and width of contact patch and single drive grip I would offer that although yes a wider contact patch like a caguama vs a 83mm flywheel will have more grip, it is a less predictable grip. The benefit to a flywheel’s classic thane and narrower contact patch is that it slips more progressively. It should give you feedback on how much grip you have left in your drive wheel without it breaking loose completely. Anyways sorry for the spill. Good luck man!
+1 can easily modify to make it fit tight side to side. or add extra mounting points. but you have a double stack hyperbeast tho and you are only gona put 40 cells in it??? I’ll trade you with my single stack
Crap I totally forgot about the fact that output voltage is limited by input voltage…
You definitely want to go higher in voltage. When you only have one motor, you need to get as much power out of that motor as possible, and given that the ESC is limited to about 60-75A output, the 30% extra voltage will really help as long as you can fit the gearing to shift that power from high speed/low torque to low speed/high torque
Depending on your top speed goals, I think 12s is ideal for single 6374 builds. The size of the wheel limits the gearing you can achieve. On my 12s, single 6374 190 Kv build, I can fit 9:27 chain drive with 8mm ground clearance, for a theoretical top speed of roughly 25 mph. If I went down to 10s, I would lose power because the ESC limits prevents me from increasing current to compensate for the loss in voltage. If I went up to 13s without touching current, it would increase power, but I wouldn’t really be able to adjust the gearing at all, so all that extra power would just show up as more top speed (which I dont really need) instead of torque. And that’s at the expense of possibly reduced reliability and the extra cost of finding a (somewhat rare and expensive) 13s BMS and charger.
Also, consider LiPo packs. With 3p or 4p 30Q packs, you are getting 60-80A discharge which is plenty, but only 12-16A charge. A similar LiPo pack will get you closer to 25-40A charge rate for almost double the high-speed braking torque, which I think is a worthy consideration. It may have slightly worse longevity, but if you just undercharge by about 10% (which is a decent idea anyway to ensure you wont have braking cutouts at the start of your ride), you can help alleviate that.
I can help you get rid of hyperbeast 
Nah gonna use it as a test mule with solderless to test 13s3p vs 10s4p. eventually I’m looking at 13s5p (65 cells). I think it’ll fit with dual focbox or a unity. maybe even quad.
Get away! Mine!
Already have a board and enclosure which limits my choices.
Well, the NESE don’t fit stacked, so I was looking at 3D printing a 2 stack compression cell holder, and looking at sourcing copper strips, etc.
Then I saw this thread
VTC5A will give enough punch over 30Q to just build the 13s3p. And so cheap, $2.69/cell.
So the science experiment is off, and cells are getting ordered.
A part of me still wants to do A/B testing…
EDIT 6-8 weeks shipping. I might not last that long…
Okay I got this built and on the road a few times. Stupid me misplaced the e-toxx cronin that was the centerpiece of this build – using caliber2 with clone enertion mount for now.
Not… Enough… Torque… (Nor brakes) Focbox is not able to get to the battery max of 45A with motor max 80A. Hit about 35mph, which is nice but not the goal for this build.
No belt skips. But motor gets hot hot hot and focbox gets hot hot hot (thermal cutoff reached). ackmaniac app also showed me an ABS CUR error with the 3 second penalty box once.
2nd try:
Better, both torque and brakes, but still not great.
As you guys said, there’s some weirdness with having all that torque on one wheel. Full throttle while leaning results in wheel spin. Full brakes feels weird, like induced wheel wobble weird.
Next iteration will be 170kv. I have 14t and 12t motor pulley, and am considering trying 44t+90mm or maybe 40t+83mm. 25mph top speed is fine for this build, as long as it gets there in a hurry (with matching brakes). Hoping the gearing will help with heat both in the motor and focbox.
Okay I think I have things pretty dialed in now. 15/40 90mm with 200Kv wasnt quite enough torque and struggled to reach top speed. Focbox also got hot, 90c and thermal backoff.
I swapped in 170kv sk3 6374 and now we’re in a good place. Freewheel full throttle shows 30mph in ackmaniac. Torque, wheel slip an. Belt slip (15mm) are all good.
With 13s full charge I think I can still get above 25mph.
Motor still gets very hot, and I may need to add more heatsink to the focbox.
Curious about 150kv now…