4WD MTB build: advice needed

DIY Builds
1

Greetings, I’m from Italy and this is my first post here.
I’ve been lurking, collecting info and dreaming to build an off-road beast since years (from electric-skateboard.builders), and now, since I moved to the alps, the moment has come!

Requirements

  • handle 20°/25° degree incline for some time (I don’t know how much Amp this equates in real life)
  • have at least 20km range

So here are the options I’m considering for the parts. feel free to suggest otherwise:

Board
My height is 1,90m and my foot is 46 and weight 90kg, I want a deck that is flexible to help absorb terrain hostility :slight_smile:
Nowadays Trampa makes the 9-73 BIGBOI(Y) 17ply quite expensive for 314,26€
I’m planing in the future to source decks from local snowboards manufactures but in the mean time I’m open to other options

Bindings
Never used for skateboarding, maybe I can use my snowboard bindings? Anyone did this before?
Are MBS F5 Ratchet Mountainboard Bindings any good? Other comfortable options?

Trucks
I’m tempted to choose boardnamics’s BN270 Precision Hanger mainly for easy compatibility with their gear drive and adjustable baseplate, and wide width 131€ (hanger) + adjustable baseplate (93€) + Bushing (outof stock) +… Otherwise:
MBS Matrix II ? (137€)
Vertigo? (154€)
Apex Air? (219€)

Wheels
please advice 8/9" ? MBS T2 Tyre? Trampa Mudplugger?

Motor
I’ve already own two ODrive 150kv motors + encoders. They’re double shafted and requires some mount trickery
I don’t know if I’ll find a suitable drivetrain to mount them and a VESC that will accept those encoders.
In any case I need to buy other two to make it 4WD

VESC
I’m not updated to the latest that came in the last 3 years, unfortunately I miss the Stewii’s batch for the ESCape back in the time.
I’ve seen a list here
Any recommendation for a VESC capable to deliver 100A+ in FOC mode? “Cheap” (I’ll need 4) also would be nice :slight_smile:
I’ve read good things about Flipsky FESC 6.6 & 6.7
but quite expensive. Maybe I don’t need 100A if is 4WD

Transmission
I have to find a way to mount my motor (if feasible in some way). In any case I’m sold on the Geared Drive solutions.
However I only know Nowind’s e-toxx and boarddinamics
An idea is to mix belt in the front (less noisy and less need for strong torque) and Gear Drive in the back, to also keep cost down.

batteries
Choosing LI-ion over LIPO for range and safeness. Hence a 12S configuration is a must. I was thinking about 5P or 6P but I don’t know if it’ll fit. I haven’t chosen the external box yet, but inside I’ve decided to give the press fit N.E.S.E. modules a go.
As for batteries I’ve good reviews for the Molicel INR21700-P42A 4000mAh - 45A
Anyone here have tested them and can confirm they can at least deliver 20A continuous?

BMS
to be decided, I like APEX smart ones (but they are expensive 45€)

VAR
I’ll need a lot of other stuff like antispark (not needed with flipsky) power switch, remote, capacitor pack (good idea or not?)

looking forward to your advice

2

@rusins

1 Like
3

Deck: haero bro
Esc: maker X dv6
Trucks: apex airs
Transmisson: BN gear drives
Bindings: mbs f5
Battery: p42a will deliver 20a happily
Bms: order direct from LLT to save some pennies
Wheels: 8inch. 9s are too heavy

Thats what i would do.

6 Likes
4

dual BN AT would b epic, agreed.

5

ESC given that when I’ve posted I’ve just read about the early bid for the D75 should I consider using 16s4p configuration instead?
Transmisson: what gear ratio would you suggest?
BMS: I see many listed here which one should I use? Should the main battery +/- be connected to the BMS or can it go straight to the VESC? I don’t understand why I should care about amp ratings if the purpose is just to balance the P group (sorry for my ignorance)

6

another adventurous who’s using NESE, It’s a tight fit, they got deformed maybe for the thermal expansion of the cell?

7

You’re probably going to run into problems trying to get BN270s to work on a mountainboard. They’re RKP trucks which were designed to be mounted on level decks and not angled tips, plus they’re narrower than most channel trucks (possible deck bite with larger tires or drives) and have 10mm axles, instead of the 12mm you find on most channels (weirder bearings).

1 Like
8

This bms. Wired for charge only.

I wouldn’t be investing in an unproven ESC given the state of the ESC market right now. The DV6 is a pretty solid ESC, hence the recommendation.

Gearing; if you’re using the 150kv motors i’d go for the 3.95 ratio. Else I’d go for 4.6 with 190kv.

1 Like
9

[I wouldn’t be investing in an unproven ESC given the state of the ESC market right now. The DV6 is a pretty solid ESC, hence the recommendation. [/quote]
given that D75 is made by the same company of DV6 and the potential to go 16s for about the same price you would still be holding off?
Given is a 4WD setup and very harsh inclines 20/25° with 100kg tol, how much current do you expect each motor will draw?
Higher Voltage == less amps correct?
Thanks for all the advices

1 Like
10

Thanks for noticing, which one would you choose instead?

11

Absolutely. Always happy to let more optimistic people have the opportunity to blow shit up first.

Watts are watts. 12s ESCs seem to be more reliable than anything else right now.

3 Likes
12

I agree with everything you suggested except the wheels. 9" are a must for any serious off-roading, and aren’t that heavy. With 4WD torque should still be crazy.

Also I would recommend heat sinks for the ESCs. Sure you have 4WD, but the produced heat will be the same if not more.

2 Likes
13

Eh I’ve done pretty serious offroading with 8 inch

9 is very slow and heavy, even truck feel is different. They are still fun but 8 inchers like MBS t1 or t3 are easier to ride on

Also heatsink not necessary especially in 4wd. 4wd is less load than 2wd and you’d be hard pressed to overheat a dv6 in the first place

3 Likes
14

Disagree on the heatsinks. 4wd with dv6 will run cool as a cucumber unless you’re towing tractors

4 Likes
15

The other ones you listed should be fine, although I’ve heard the Vertigo hangars tend to warp easily.

16

image
image1920×1440 759 KB

I just built this one. (For a client) It has 9” which as has been said is a little more ponderous and heavy but useful for really rough conditions.
I did another one a couple of years back and used 6355 motors and was very useable.

2 Likes
17

What peli are you using there?

1 Like
18

Peli 1200 with Apex NGB battery. 12s6p p42a.

2 Likes
19

vertigo by Trampa? Ive had mine for a while and weigh about 260, I jump a bit but no serious ramps yet just grass hills. no signs of warping!

20

Yeah one of the major benefits from 9 inch is you have tons of ground clearance

1 Like