52mph Mongoose Dolomite deathtrap

[emy5023]

I see so many well made bikes on this forum, so this is going to make you all cringe.

Pre motor:

This is a temporary build, I'll hopefully soon have the motor in the rear of a full suspension frame. The motor is a Magic pie 2 rear, but the axel was too short to fit into the rear dropouts, so I threw it in the front. Yes, I know, 6,000 watts in the front wheel is idiotic...

Controller: 18fet infineon with 4115 mosfets
Battery: 30s10ah Hobbyking Lipo (20c) (6 6s5ah packs and 6 4s5ah packs) (already have a good 2,000 miles on them from my last build)
Tire on the motor is a cst cyclops pro 2.4inch that's already balding from the 2,000 miles on it from my last buld (a 4,000 watt blackcomb)

Even with the 4inch fat tire in the rear, I hit 52mph on GPS (I was wearing full motorcycle gear)
[youtube]aW9OfPagSr0[/youtube]

Moved the pack in front of the seat for a better weight distribution/more secure mounting.

Probably the worst part, my temporary torque arm setup (have one on each side) Under acceleration, they're turned towards the forks, the zip ties are a fail safe for reverse torque (I rarely use regen at the moment....I have a proper torque arm coming, as well as some hose clamps instead of zip ties)

Obviously, this setup is not ideal. Lots of wheel spin. I might keep this for a couple more weeks and remove it from the fatbike frame this spring. I may move it to the rear of my blackcomb frame or may get a new one. Also on the way is a front bb7 disc brake caliper. Still need to order a Cycle analyst.

There you have it, a hacked together 6kw front wheel drive walmart bike that breaks 50mph. Feel free to cringe and tell me how stupid I am

 

[dingoEsride]

There is something about the name Mongoose that makes me look, and you lucky guys that get to have fun in the snow, love it,

for you tube just put the aW9OfPagSr0 between the youtube brackets above, have fun youall

[youtube]aW9OfPagSr0[/youtube]

 

[dingoEsride]

Probably the worst part, my temporary torque arm setup (have one on each side) Under acceleration, they're turned towards the forks, the zip ties are a fail safe for reverse torque (I rarely use regen at the moment....I have a proper torque arm coming, as well as some hose clamps instead of zip ties)

that set-up will work fine under power (axle spins up towards fork) but the axle will want to spin the other way under regen braking

 

[TSAR]

Wow that looks really dangerous! Those nylon ties will not hold [strike]much[/strike] any force, I would turn regen off for now.

 

[spinningmagnets]

Several builds that have regularly taken their E-bikes over 40-MPH have gone to DOT moped tires (Pirelli ML75?). Doing this on the very cheap Chinese fat tires that came with the Dolomite is not wise.

edit (*cringes HARD!)...torque-arm...made from Chinese beer cans...on only one side...front hub at high power...

 

[emy5023]

I do have a proper torque arm coming. I had the grin version 4, but the screw came out or something, and I've misplaced half of it. I was just impatient and wanted a running ebike before my new torque arm arrived... I agree that the fat tire is a bad idea and won't be sticking with this frame (will probably go with maxxis hookworm or the cst cyclops again.) I'm going to avoid regen until I have a real torque arm secured. I normally commute around 20mph and have the 3 speed switch set to 50% (giving me around a 30mph top speed). I just did the 52mph run out of curiosity (for science). I don't run sustained speeds like that. I do have a torque arm on BOTH sides though, not just one (but the other sides isn't any better)

 

[dogman dan]

Wow, you called it. Deathtrap.

Weld some attach points to your fork, to hold that much power. Even with the good grin TA. That's what I did with my 47 mph front hub race bike.

 

[cal3thousand]

If I were a praying person, I would pray for you. But I'm not... so I'll wish you good luck. That new pack location looks like it would hurt in a minor crash. And in a major crash, you won't feel a thing

 

[emy5023]

Finally got my new torque arm in the mail. I could add it to this bike, but I think I might just put the motor on the back of my old blackcomb frame with the new torque arm.

 

[dogman dan]

Here's how you do a good torque arm on a blackcomb frame.



Put a regular torque arm on the derailleur side, for that much power. But I ran this by itself on the disc side at 3000w with no problems.