I’ve built a few small boards, one with the Hummie deck and hubs, but always wanted to do a mountainboard. Been putting this one together the last few months. This is ‘The Rip City’:
-MBS DWII Pro 97 (added red Rockstar II hubs, F5 heel straps)
-Idea Matrix II motor mounts v7.8 (I took them to a local shop and had them anodized in red to match the theme of the board) 15t steel motor pulley. 72t aluminum hub pulley (1:4.8 gear ratio)
-Tattu 14000mAh 25C 6S1P lipo x2 wired in series (gonna try this at 12S and then look to upgrade battery later)
-Dual TB 6380 190kv
-Lacroix Stormcore 60D
-surfnacho’s InfinitySink and top mount box
-Controller, two options:
Puck Puck Bruce / Hoyt St. mod controller w/ new nubbed wheel and Metr Pro internally
OR Trampa Wand (I like having data display in-hand)
-Junction box for batteries (10.4”x7.2”x3.7”)
-Waterproof 90 degree cable gland for top mount box
Total weight: 33.6lbs (15.2kg)
Painting and frit
I live just a few miles from Bullseye Glass (http://www.bullseyeglass.com/) so I decided to do a custom paint and glass frit job.
First, I sanded down the deck to remove the shiny protective coat.
Once sanded, I spray painted it matte black.
Then I added 2 red racing stripes on the top.
On the back I decided to paint the Portland downtown skyline. I designed it on my computer, printed it out, cut that out as a stencil, then penciled it in on the deck.
Then I painted it following my light pencil markings.
Now to seal this all in. I went with Helmsman water-based spar urethane. Not smelly, easy to work with, easy to clean. The one 22oz can will last for dozens of boards. Took about two hours to dry between coats, though I’m really patient and mostly just did one coat each day. Did four coats on each side. I tired to really lightly sand before each new coat but I’m not sure it did much and I didn’t want to do too far and ruin the paint job beneath. After each coat (while still wet) I was careful to check the edge of the deck all the way around to make sure there weren’t any drips. If there were I just smoothed them out w/ the brush.
Now for the frit. I picked up Bullseye clear transparent medium frit. In retrospect I wish I had gone with the fine frit instead of medium. Medium is pretty beefy/sharp/overkill. Started by masking the area within the foot straps.
Layed down one coat of spar, then immediately sprinkled the frit evenly across the area. I used an empty cinnamon spice container w/ perfect holes to evenly spread the glass.
Used a pair of tweezers to drop a few more pieces of frit where holes needed to be filled in. I removed the blue tape before it dried to ensure clean removal.
Let that dry at least a few hours.
At this point the frit is barely held in place so it’s important to add four top coats of spar, letting each coat dry before adding the next coat.
Motor Mounts
Idea set me up with the right motor mounts for my matrix II’s which are notorious for not all being exactly the same length. I was able to measure mine once they arrived and idea made me the exact crossbar I needed.
Then I took it to a local shop and had it anodized in red to match my color scheme. We’ll see how well the color on the aluminum holds up to scrapes/chips.
Electronics
Painted the junction box to match the stripes on the deck.
3D printed XT90 panel mount for the battery box. Dremel’d a hole to glue the mount into.
Junction box is attached to the deck with two bolts, large washer to distribute pressure, and 1/4" adhesive foam between the deck and box to pad it/reduce rattle.
I’ve got the Stormcore mounted inside surfnacho’s top mount box. I ordered the version with the “foot side” entrance for the +/- power cables, but found that was a really tight fit next to the toe straps. Notice how there’s no room to ratchet the straps tighter:
Had to drill 4 new holes in the top mount’s base plate in order to shift the box far enough away from the ratchet straps.
Decided to cut a new hole for power to come in heel side. Main concern was to keep the cables fairly close to the box and straps to eliminate their chance of getting snagged on something while riding. Everything is SO tight inside this box. Can’t fit even the smallest USB-C cable into the Stormcore unless you pop it out of the panel mount box a bit.
Final touches
Added cable wrap to keep things tidy and match the color scheme
Locktighted all the screws, padded the inside of the battery enclosure
Inflated the tires, and she’s ready to roll! Cruised around the park for the first time today and this thing crushes through sticks/debris. I’ve never had a deck with foot straps and they make it so much easier to carve deeply without fear of falling off.
I’ve got it set at 45A/-40A battery amps on each side, and 150A/-70A motor amps. Gotta find some hills because so far I haven’t come close to those limits!
I’m actually a bit sad that I’m done building this. It was so much fun to problem-solve each step along the way. It has an impressive amount of power compared to anything I’ve made before. Makes it so much fun to ride. Now what do I build next? hehe
.
.