60-70kph build pulley/mounts help (trampa/boardnamics/other related)

I’m planning a build for the following season

deck: the 44 from @redember witth DIY fiberglass enclosure
battery: 12s10p 50E
vesc: unity (of course)
trucks: 240 fatboys
wheels: trampa 7" inova on offset rims with center spacers for 8mm axile

and some dope stuff like the DAVEGA from @janpom, metr pro, RGB underglow, neptune 15 bypassed for discharge and some bright LED front lights

the thing that grinds my gears is the drivetrain. I can comfortably say that I need the trampa 6376. the problem is that I have no clue of the following:

  • mounts
  • pulles

I’d like to run with the motors not under deck (is it somehow called?) and with dropped-through trucks

mounts option 1 - boardnamics

I’ve been riding @Boardnamics mounts without the idlers, unfortunately, as they fit calibers I had to “fix” them a little with a file. the thing is that I do not feel so secure on the board in 55+ kph partially because of belt skipping.

boardnamics also offer mounts with idlers, which I’m not sure would fit - I’m especially concerned with fitting a bigger pulley and still having some space for the belt.

on positive side, I already have the filed clamps for the fatboys which are rock solid. slight bending can be compensated with two rods holding the mount behind the motor. not sure here about the clearance with the trampa motors


  • do have idlers
  • I already have the hanger clamps


  • no clue if there will be clearance for 7" or 8" tires

mounts option 2 - trampa

trampa mounts for 12-fifties which are @Trampa , should fit the fatboys, but also with some tinkering. the 12-50 hanger should be 19.8x19.4mm and fatboys are 18x19mm. I’d have to make new middleplate for the fatboys or use a lot of locktite on bolts to fix them in place

they can’t be fixed with rods behind the motor but are carbon fiber which should flex, not bend

positively they provide motor axile support but the pulleys they provide suck, more on that later


  • its trampa, it shoud hold (flex :smiley:) strong
  • oversized motor axle will be hidden in “motor axle support”


  • no idler, belt skipping is inevitable
  • no clue if have enough clearance for 7" or 8" wheels

pulleys option 1

go with the trampa mount. pulleys are included, but wrong for my usecase. on 7" tires, 15 teeth motor and 62 wheel pulley on 12S is it 45kph. slow!

if I changed motor pulleys for 18-20 teeth there will probably be no place to put it, as the axle support will be in the way. :frowning:

pulleys option 2

boardbumpers 58. its nice/bad they are not screwed to the wheel. not sure about that. I’m neither sure if they will fit the fatboys.

these would have to be paired as well with 18-20 teeth motor pulleys for sufficient speed


it’s a shame there is no “standart” usage of belts wider than 15mm. with wider belts there might be no need for idlers

it looks like the trampa kit is out of the game for me because of the low gearing ratio

what do you think? are there any other options that should be considered?


You know you can get by even with 9mm belts? As long as you have at least 6 teeth in mesh .
Just get a set of @Boardnamics hangers+mounts ( you may ask for custom length) .
For pulleys check @IDEA @NoWind @Janux-esk8


I should have a 20mm belt setup for Trampa/MBS. Finalizing the drawings which should arrive soon. But sounds like you’re going longboard trucks.


The 6376 fit on our 12/50 truck, using offset hubs and a offset bearing spacer.
The CF plate is very adjustable and you will be able to mount bigger motor pulleys.
The Motor axle bearing support will not fit if you use bigger motor pulleys.
You could use our 44 tooth pulley and 14 or 15 tooth on motor side and go for max speed.
Calculated on 175mm wheels is 72.5Km/h. It is crazy fast and we do not promote to go that fast!!
If you want to set a record at your own risk, we can’t hinder you.
The CF plate has an option to mount an idler. We have that idler and axle in stock.
It all fits together pretty nicely out of the box.


He does custom length motor mounts??

Not really as I am not the manufacturer anymore. Custom hanger lengths are available so long as there is at least 20pcs worth of demand. This is why I got some 184mm and maybe Ill make 240mm