Build me a center drive Ebike

[snellemin]

I build me a center drive ebike with a GNG kit with 12s1p lipo. The kit needed some tweaking and got it to work. Found me a Giant Prodigy frame on ebay and started from there. Well the bike is nice and light, but can't handle the torque the motor/gearing setup produces. The rear of the frame just twist under load. Bummer that after all that work, I will have to take it apart again and set it up with as something different.

[Semi Pro]

thats sexy


is that a kit or custom drive set up?

[snellemin]

Thanks Semi. It's a kit I bought from Hong Kong. Also available through Ebay. I opted to buy directly from their website and paid for the fastest shipping to reduce handling damage going with the slow boat.

[bdebde]

That looks nice. What kind of speeds will you get with it?

[mistercrash]

He won't get much speed out of it me thinks with the rear end twisting from the torque. That bike is uber nice, it really looks fantastic. But the rear part does look a bit flimsy which is a shame, this bike really looks awesome. Any way of strengthening the rear? I'm guessing that it's all aluminum?

[snellemin]

Speed wise it felt like 20mph or so. I don't have the Cycle Analyst hooked up yet. I tested the climbing ability in the retention pound and speed in my neighborhood. I broke the chain the second time out and had too buy a new one. Also have a wipperman chain on order.
The bike is nice and took me a bit to find all the pieces to build it up. It's all aluminum and would be nice if Monster Mike could build this drive setup for us to run with big outrunner motors and Castle ESC's.
The bike really fits well and is so easy to ride. Everything is so well balance and would hate to mess it up with a rear mounted motor.

[_paralyzed_]

I don't get it. Is it a ratcheting crankshaft with a fixed rear gear cluster?

To me it looks like the pedals would be spun under power

[snellemin]

nah, the pedal cranks are also on a freewheel setup. I'm guessing a vid is in order huh.

[_paralyzed_]

Originally Posted by snellemin

nah, the pedal cranks are also on a freewheel setup. I'm guessing a vid is in order huh.

I get it then. I said "ratcheting" crank, you said freewheel, we mean the same thing.

I had a schwinn road bike years ago (back when me legs worked) that had the freewheel at the crank rather than the gear cluster.

Is that a hose clamp holding it to the down tube?

[snellemin]

That hose clamp keeps up a bit of the weight. Most is held by the bottom bracket, which is also supplied by the vendor.

I feel stoopid missing the "ratcheting" remark. You can tell I'm not the brightest Sherlock around.

This is what came in the box.
controller, crank, bottom bracket, throttle, small chain, and the motor/tranny assembly.

[Semi Pro]

Originally Posted by snellemin

Thanks Semi. It's a kit I bought from Hong Kong. Also available through Ebay. I opted to buy directly from their website and paid for the fastest shipping to reduce handling damage going with the slow boat.

do you mind if i ask what it cost?

[snellemin]

It was 436 with the fast shipping. Go cheaper with the shipping and you risk damage to your package.

[snellemin]

So I stuck GnG drive in a Hard tail Fuji bike. I'm going to use Lyen 6fet mini monster, Left hand throttle, 3 speed switch, with 14s1p lipo.
Replaced some of the metal spacers with Nylon ones. The spring on the idler is tighten up a bit, adding some tension to it. I'll add some threat locker too. Got to see what other screws I can find at the Ace hardware store. Still need to finished wiring it up and adding the CA. Installed a Connex 9 speed chain, hoping I won't snap like the chain on the Prodigy.

[Semi Pro]

cool update

[_paralyzed_]

I love the color scheme of that bike