Well I’ve got more updates boys. I’ve undergone an upgrade or two and some changes in the build, all of which have been great fun. This build has been “done” for a while now but I like to switch things out and try out different wheels from time to time.
This is definitely my best build to date and I can’t even put a number on how much time I’ve put into this, and one of the best parts of this build is that it’s pretty easy to make drivetrain changes. That being said, I did finally get around to putting on my Bergmeister wheels and tires to try them out. Long story short, they’re terrible and awesome at the same time. Let me explain. This was my first experience with pnummies so I wasn’t sure exactly what to expect. I knew that the ride was going to be super comfortable, and I knew that I should expect 24-30 wh/mile of consumption compared to the 14wh/mile on my urethane wheels.
I did not expect the wobbles. Two of my Bergmeister tires came totally wobbly. The wobbles were manageable up until about 22-25mph. After that, it felt pretty sketchy. I tried numerous things to try and get them to balance out, but to no avail. I really enjoyed riding them though and I was determined to make them work. After riding the wobbly tires for 50 to 70 miles or so I decided to switch out the two worst ones for my clever 6" tires that I had sitting around and hadn’t gotten around to using yet. I ended up going with the setup where the two rear tires are the clever ones and the two fronts are the non-wobbly Bergmeisters. I like how the Bergmeister ones ride and they have slightly less contact patch than the clevers.
I personally think having the clevers on the back looks great, and they work really well in my experience so far with the Bergmeister hubs. Some people have said that the experience some wheel shift because the ID of the clever wheels is too big, but mine are good. Mine do not wobble at all in my experience so far.
I think the build looks awesome with the pnummies and I’ve been pretty spoiled by how well they run. The ride is super comfortable and nothing feels quite like mashing the throttle on pnummies. You don’t really know until you experience it.
The other upgrade that I made was from my 6355 BKB motors up to the new Flipsky 6374 motors. These have been running for about 50 miles now and I’m impressed with their performance. They run great and I’ve got a higher limit at which I can throw amps into them. Unfortunately, this has lead me to discover how severely the Go-Foc Retro thermal throttles. With pnummies and the new motors, it will only take two or three major hills at speed to heat soak the ESC. I have my thermal limit set at cutoff start at 85. I’m wary about going higher than that with my internal mounted VESC. I am thinking that I may bite the bullet and figure out how to mount the ESC so that the heatsink fins stick out into the air. This may be the only solution to my overheating issue.
The last ride picture up there was taken on my range test of the board. A fateful test. A painful test. You don’t know how annoying pnummies can be until your battery runs out 1.5 miles from home on a hill. I just overestimated my range on the ride and ended up walking the end of it. Well, at least I know what my range is now. My range on the 12s7p of “salvage” Samsung 30Q cells is officially 23 miles before it becomes unusable. That was starting at a charge per cell of 4.15v and ending at 3.2v. Here’s the Metr and Strava rides for those curious. If you inspect the ride closely, you can see my ESC bouncing off of thermal limit pretty frequently. It really is annoying getting halfway up a hill and having to stop and wait for the ESC to cool down.
Overlooking the battery running out, the ride was awesome and really was probably the thing that spoiled me on pnuematics. The ability to just glide onto a gravel or dirt trail is pretty awesome and all the concrete cracks fade away into nothing.
One last thing, I did end up finishing off my headlight build and it’s been holding strong on the front of my board for over 100 miles now. The ms paint schematic that I drew up there is the basics of it. If anyone wants to re-create it, I can explain it a bit more. In the module with the lights, I have the smaller buck converter that drives the LEDs. I found a good balance of the current so that the LEDs won’t overheat while riding. I wouldn’t run it if it was hot out but when riding at night time the lights have no issues staying cool. I used thermal paste when mounting the diodes into the heatsinks to make sure that they were fully utilized. The lights really make a huge difference riding in the dark, I can actually fully see where I’m going. More importantly, it makes me very obvious to other vehicles and persons on the road. Here’s a short vid of my friend riding my board with the lights on!
To summarize. This build is awesome. The ability to switch out wheels on the fly with the idler’s and massive range in the pack make it just an awesome thing to ride. I ride it whenever I can and I can’t wait until summer comes around and I can ride it after working a full day. I’ll leave you with two pics of myself and by Fiance on our ride the other day.
