Recommended Kit for a Noob BMX Build

[wutangclams]

Hey Everyone!

For a few years now I've been drooling over the idea of a bmx e-bike build.. from time to time I would visit this forum and fantasize.. and then real life would pull me away for some months.

Well I'm finally ready to commit. I want to base this on a bmx for a few reasons.. relatively cheap, lightweight, designed to stand abuse, and tons of fun when I was a kid.. but I have ZERO experience with pulling the trigger on this, and all my previous endless sphere research is quite outdated by now.

Can anyone recommend a good rear hub kit that would fit the bill for the smaller frame/tires of a bmx?
I was thinking about getting a kink bmx from amazon.. or just trying my luck on craigslist (dirt cheap), so I dont know an exact tire size yet.

I want to mount the battery behind the seat to look as inconspicuous as possible.. although I understand this will sacrifice some performance..

I would like to be able to top off at a theoretical 45mph.. but I dont see going beyond 25mph much as I do value my wellbeing..
20-30 mile range @ 25mph unassisted would be great.. is that too optimistic?

oh yeah and i want a twist throttle =)

Cheap would be great.. would yescomusa have anything that might work?
I'm open to any suggestions as I've forgotten the little things about the computer controllers and stuff long ago

Thanks so much!! Very Excited!

additional details that may help: 5'11", 211 lbs, chubby, 31 years old

 

[dogman dan]

A front kit might fit the rear of your bmx. That's been done. No chain or pedals though. Not like you were going to pedal at 45 mph.

If you want to use a gearmotor, the Mac 6t at EM3ev is one of the fastest wind motors commonly available. Not sure you'll reach 45 mph though, without going to a voltage too high for a mac to last so long.

Wear your leathers for 45 mph on a bmx frame.

 

[Drunkskunk]

BMX have been done. Recomending a motor is hard to do without knowing what bike you'll use, and the wheel size. 20" is normal for a BMX, but there are other sizes, and that makes a difference.

I loved my BMX when I was 11. by the time I was 13, I was ramming my knees into my elbows when I tried to pedal. I was only 5 foot 6 and 110lbs back then. I'm 6 foot and 180 now. I wouldn't even try to ride a BMX.
All I'm sayin' is you might want to try before you buy.

45mph is possible, if you have the cash to spend. Most bikes won't survive that kind of speed, though. Possible but not very realistic for most bikes. 20 miles range minimum at 25mph is realistic, but does need a rather large and expensive battery. 20 @ 25mph maximum range is a whole different story, using a probably much smaller battery. The key here is to know exactly what you need the bike to be able to do at the minimum. Then if you want more speed or range or torque, you can make the tradeoffs or upgrades required.

 

[wutangclams]

Great advice!!

20" tires is looking like the realistic choice since so many bmx's come in that size..
any recomendations for 20" bmx ranging 20 miles MAX at 25mph?

I can always recharge before heading home..
is pedaling out of the question? i wanted this to entice me to burn some calories

 

[dogman dan]

Pedaling a bmx at 25 mph, yeah. Unless you get a really huge crank on it, which might rub the frame.

Now that we know you mean to pedal, I can't say hard enough that a 20" bmx bike won't do. But a larger one, if steel, could be modified to take a 20" rear wheel with ease.

I'm not sure what to say, but what you want sounds a lot like what member Cwah rides. You might look up his folder bikes.

25 mph for 20 miles, a 48v 15 ah lithium battery will be ideal.

 

[wutangclams]

ok..... i broke and bought a 20" bmx

i love the honesty on this forum, and totally was convinced that id never be able to ride such a small bike.. no way...
i put it out of my mind.. but something made me check CL one more time.. and there it was.. the cheapest 100% chromoly bike ill ever come across. I had to go see it just to refresh my memory about how small these bikes really are.

Well.. I got there and saw it and knew I was going home with it. I rode it around a bit, maxed out the seatpost, rode it some more, and with a smile from ear to ear I tossed the man a few crumpled up bills and with little effort tossed the bike in back of my fiat abarth.

I'm stupid, it was cheap, strong and light, and I'm having a blast riding it around my neighborhood.

With an extra padded noseless seat (schwinn no stress) *you've got to see what that looks like on a bmx* and the oem seatpost maxed, sit-pedaling is very manageble. .. not comfortable, .. but not uncomfortable.

When I'm just pedaling around, I stand for speed, and sit to keep the pedals going. Not bad for short distances.. though I wouldn't want to pedal for 15-20 miles.. but then again, that's why im here

I considered folders for their small footprint.. but the strength of the bmx bikes kept drawing me to them.. that and the price. These things are like tiny brick shithouses!

I'm in no rush to modify this bike as I'm still having fun playing around, but my e-bike needs have totally be refocused.

You're 100% correct that high speeds on such a small frame with my feet so closed to getting sucked under the pedals would be less than safe, so my priorities have shifted toward longer distances at lower speeds.

I defiantly want to retain the ability to pedal with or without power.. so if I need to mock as though the bike is in fact not an e-bike, I can slow to a pedaling speed and pedal.

I noticed leafbike has a 20" 48/1000 rear kit. Any experiences with that?
Also, They have some less expensive batteries that might fit with my goal changes above.. any suggestions?

Also, for those times that I might want to stretch my legs out a bit while riding... would motoring with my feet on the front pegs be unsafe?

Thanks as always for your blunt honesty. I'm sure you get a lot of noobies. We appreciate your patience.