I’ve tested a bunch of electric bikes on the beach and I’ve always found the same problem. Ebikes generally work great on the hardpack but get bogged down in soft sand to the point of being basically mostly unusable. I took a trip down to Florida for 2 weeks and dragged along my Phat Phuk build which sports massive 5.05 inch Snowshoe 2XL tires. It did great on the hardpack as I expected it to, but it’s performance in sand that was so soft it would have gotten a Humvee stuck, my 5.05 inch tired Phat Phuk & BBSHD combo blew me away.
I ran the Phat Phuk with a tubeless setup with 5 psi in the front and around 7psi in the rear. I felt like you could go even a little lower than that as on the beach you don’t have to worry about bottoming out the way you would when trail riding. The front rims are 100mm and the rear is 80mm and performance should be similar regardless of the frame you are riding.
I tested this bike in two separate locations with 2 different conditions. On the hardpack beach of New Smyrna beach in Florida and on the incredibly soft sandy trails of Wekiwa Springs State Park, home of the Manatee springs. Wekiwas was a pretty darn cool place where you can Standup Paddleboard right up to manatees chilling out in the reserve. The bike trails basically sucked and were so soft that our normal bikes quickly got bogged down and could just not move at all. The Phat Phuk took it all in stride without missing a beat. Normally trail riding with the BBSHD the unit hardly ever breaks 120 degrees Fahrenheit in the controller, but in the soft sand on full throttle, it quickly got up to 140 F which is my usual shutoff point for the BBS02. The BBSHD has a much wider power range and delivers a lot more power at lower RPM’s and pedal cadences than the BBS02. That being said under high loads like incredibly soft sand the BBSHD still wants to be driven at a much higher RPM speed in order to keep motor temperatures down. The BBSHD also seems to shed heat much faster and I was able to drive the motor at 140F for quite a while and the windings didn’t melt. Keep in mind that is the controller temperature with a cheap probe siliconed in so the motor temps were probably running a lot higher than that. The controller probe is there to give you a better idea of what is happening in the motor (is it getting hotter, is it cooling off, is it staying the same?) and not the exact temperature.
The BBSHD with the monster 46T factory paperweight that Bafang calls a chainring wanted to be ridden on the larger granny cogs in the rear. In the soft snow once I got up to speed the tires just seemed to ‘float’ on the sand and if I could shift into a higher gear and keep my momentum up then I could scream along at a pretty good clip. Sand got flung everywhere including onto the chain and the drive unit made some very strange noises when I pedaled but I was having so much fun I didn’t want to slow down to figure it out. The front tire would tend to follow the ruts that previous vehicles had left in the soft sand but it was quite easy to drive the bike up out of the ruts with enough speed. The huge tires produced a lot of rotational momentum which added to the stability and the rubbing of the tire on the front fork at 20mph and faster was so loud that people could hear me coming from a long way away. Ironically the rubbing tire at high speeds sounded a lot like a gasoline motor.
When riding the bike on hard pack it could easily hit 30 mph or faster with the BBSHD. This is mostly due to the fact that the diameter of the 2XL tire is insanely large and acts like having a much larger front chainring than you actually have. The fat tires and not that useful on hardpack, as we were running a 700C non-electric road bike with a 1-inch wide tire and it did just fine on the hard pack. The soft sand is where this build and motor really shines, as any ebike will be fine on hardpack.
The biggest problem I saw other than heat was the sand and saltwater getting everywhere. Any exposed steel parts on your bike are going to quickly rust with the salt water and the sand will make short work of any chain. I don’t have answers to those issues although a belt drive with an IGH might be a better solution. The BBSHD was built expressly for heavy-duty applications like running through soft sand and paired with the Snowshoe 2XL is totally up to the task.