BBSHD on SE Fast Ripper/PK Ripper BMX Bike

[HunterBranding]

Hello! I’m new here and wanted to share my experience building an ebike, as well as, get some tips from y’all gear heads. At 6’ 4” , 275lbs, I never thought I would fit so well on a BMX style bike, but I do. I started my bike build out buying a brand new SE “Fast Ripper” 29’r. It’s awesome, and fits like a glove. Amazed really. This bike is similar to an old school BMX, but it’s been enlarged with a 24” top tube and 29” wheels. The end result is a lot of smiles per mile. I purchased a BBSHD 1000W motor, 52V 13Ah Panasonic cell Battery, Lekkie motor cover, Lekkie HD40 chain ring, and Lekkie Buzz Bar Cranks. I’m running stock everything else, including the hydraulic disc brakes that came on the bike, yet I installed the brake sensors that cut the motor off when you apply brake pressure. Today was the first day that I had it hooked up enough to take it for a ride, but I was missing the clutch (broke the retaining ring that holds the pawls on. Currently the bike is running straight electric - no human cranking power. Since I have to take the motor back apart to fix the clutch, all of the wiring is super temporarily and a big mess, but I just could wait to see what this thing could do as it stands.



I rode it for 6 miles and used about 1/4 of the battery. The terrain included a steep hill, a few moderate hills and some flats and downhill neighborhood streets. On flats, and remember I am a fat ass right now, I got it to 31MPH, and on moderate hills it went 18-22MPH. On steep hills is chugged up at 15MPH. The bike has 10 gears on the back and one 40T on the front. I used gear 5 on the back for everything (and should have geared down when going up one steep hill - kind of brain farted that one).

I will be fixing the clutch tomorrow and will ride it some more. Overall, I think it’s going to be pretty rad. I bet I get 14 miles using throttle only, which sounds pretty lame, but I will never be doing that. This bike should get me 24 miles with the riding I plan to do. We will see!

Happy to answer any questions. And if you are a big guy that wants to relive his 80’s childhood, this is an awesome step in that direction.

I still have to figure out how to clean up this wiring. Someone should invent a super whizzywhig system for that! ;)

[73Eldo]

Looks like fun. I like to use 2 miles per amp hours as a ballpark estimate so I agree with your 24 miles. For me that 26 would just be what I plan to ride, if all goes well that should bring me in with some in reserve for things like maybe feeling a little lazy, headwind, or maybe a detour. You don't really want to plan on running it down to near the cutoff point because of sag. Sag is normal and not a big deal if you are at say 50v and sag down to 47 on a hill climb but if you are at 45 and have a climb that could push you below the BMS cutoff. Note that some BMS systems won't reset unless you connect to a charger.

[boecherer]

This is very cool. I found it doing a search for "se fast ripper electric". I'm possibly going to embark on the same project, or similar. I may get the bike and ride manually for a bit, but might modify the bike with a mid drive motor and put an IGH (Internal Gear Hub) in the back and go with a belt drive. Typically the frame has to be "split" to use a belt, but there is a belt that can be taken apart and put back together so the frame doesn't need a split.
Do you have any more updates? Did you get everything working smoothly?

[Hoovis]

I still have to figure out how to clean up this wiring. Someone should invent a super whizzywhig system for that! ;)

HunterBranding, did you ever get the bike wiring cleaned up? If not, feel free to holler. I found this post in a search to see if anyone else had built an e-bike from an SE bike. My son wheelies for hours on his SE Blocks Flyer, so I got my own Big Flyer and converted it... just so I can keep up with him on any terrain.

When you are in Seattle, I'm just across the pond from you. Compelled me to sign up on this forum and post a reply. Mine is a BBS02 750W, 48V 20Ah. My new favorite toy. Perhaps some day we can meet up for a rideout and/or to compare notes. Yours is very cool!

[boecherer]

That's pretty cool Hoovis. Per above, I'm still going to probably build an SE Mike Buff Fast Ripper and put on a CYC Photon motor which is fairly compact and a small battery for around town - I do want to get some exercise so I do want to pedal quite a bit, but add the motor for when I need to go to the store or ride to a client's place or climb hills. I will probably just keep the included gears that come with the bike to start and maybe go to an IGH (internal geared hub) later. The Mike Buff has the brake cables run inside the frame which hides them. I might get a 3D printer eventual and make can print some custom clipped to hide/secure the other cables and wires a bit.

[sinosoul]

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It's 3 years later, and I have a "spare" 120mm BBSHD after tearing down another project. I will be getting a fat ripper (100mm BB) and putting on a small 52V 15ah battery pack for a wheelie machine built for lols. Thanks for all the inspo