Grizzl-E's build thread

[Grizzl-E]

Thought I'd start this while I'm finishing off my winter build. Fat bike with MXUS 3000w.

First though big thanks to everyone on the forum who spends so much time spreading the ebike grin. Mad props.



The bike as it stands now

Boris x5 scored on bike island with no rear wheel. Only a 170mm rear end but too good a deal to pass up.

A kinaye motorsports MXUS 3000w dd rear hub laced by them into a 100mm rim. 6t motor. 190mm custom axle.

80a field oriented controller from ebikes.ca first production batch.

(3) 6s 16ah hk lipos in series for 18s. Bulk charged by 3 meanwells in series.

Summer v8 tires.

CA for the dashboard. Luna cycle 10w led lights x2 for backwoods night riding.

Upgraded to 203mm front hydraulic disc brake.

Do do list:

-Install sabvoton 200a controller and pull wheelies.
-build 20s pack from 100 LG HG2 18650 cells when they arrive from Luna cycle.
-find the biggest studdiest tires that will fit on this thing for the winter.
-wait for rear lights, bms, cargo bags etc from China.

 

[Grizzl-E]

Reserved

 

[Grizzl-E]

Reserved

 

[Brentis]

More pics, more details.The good, the bad, the ugly.
Unzip that bag and show us your goods. :wink:
80a not enough? You got it bad brah!
Able to make a vid?
Get someone to record your rear tire from a stop to full throttle.
Man I bet it looks like a top fuel drag tire on launch with low psi.

 

[Drunkskunk]

That thing is looking good. Once you go Fat, you never go back.

 

[Grizzl-E]

That thing is looking good. Once you go Fat, you never go back.

That means a lot coming from you dude. Btw have you ever melted tubes in your fat tires from running at high speeds? Or is that just a myth?

 

[Grizzl-E]

So my friend wanted to ride this bike. I told him it was underpowered at the moment and it was very difficult to wheelie with the current controller.

He disagreed and my rear rack suffered the consequences.


Ironic since I just received my new sabvoton controller


And seeing how it's a monster I was just going to throw it in a Chinese top rack bag till I get around to making it all pretty.



Oh well. I took the rack off and shortly after had a good wipeout that likely would have torn the rack right off. Luckily my riding gear saved me from the worst of it. Though I do have a hilarious black and purple patch the exact size of my iPhone 6+ on my thigh. Turns out they do bent back pretty easily.

Thank goodness for downhill riding gear.


Anyway I have to get rid of these v8 tires. They suck in mud.

 

[deepfraught]

Wow am building something similar, same batteries I think the 6S2P 16Ah turnigy.
I was wondering whether 48V 40A would be enough to power wheelspin in sandy beach, am guessing not
I have 72V 35A controller for more wheel speed I was going to try first... but looks like time to stop starting small?
I didn't think I needed huge torque for the sand as I can break traction taking my bum off the seat just pedalling in short gear... but it's all a new test anyway, don't know how the extra wheel/motor weight will cause more traction and harder to break it etc. I guess the answer I know is coming "more power" =P
I'm only on my 4th outing of pedal only wheelies practice, thanks to the short gearing easy to crank once and get it up, rolling through and landing well don't come so easy, so I'm a bit worried about short wheelbase power wheelies, I guess less to do when not pedalling and just twisting throttle covering rear brake.
Anyway... subscribed

 

[Brentis]

Glad to hear you guys are both ok.

Did you dump because of the questionable v8's in mud? Or too much power with the Sabvotron? Maybe both? :wink:

I have a rule with lending friends my favourite bike. Never again.
Had a friend dump my favourite Motobecane moped.
I loved that bike. Reliable. Handled well. 50kph. Freedom to a 16 year old.
Not after the dump! Fork and or frame tweaked. Never ran or handled right again.
Had to sell my baby. Moved onto cars and it took 20+years to get back off them.

Ride on.

 

[Grizzl-E]

Yes the v8's slick up something bad and don't self clear at all. I don't even have the sabvoton on yet. I was still going way too fast in fresh rutted mud. Totally my fault.

I added these to keep the low pressure bounce from chucking me right off the pedals and they keep me on the bike so much better! Helps when I can stay upright anyway

View attachment 1

And my new bb bearings got here so I can trade up to my 22/34/48 front crank set. And hope the 9speed derailer I got can be made to shift that massive range. Yay!

 

[Grizzl-E]

I used these as cheap TEMPORARY clamping torque arms on my mxus 3000w hub on my fat bike. Wanted to ride while I waited for proper ones to get here.

After heat treating and putting some shrink wrap on. These are the ends of some cheap turnbuckles that I had laying around.
View attachment 1


Worked great for a couple hundred k with some good wheelies and hard regen in there.

And waste not want not, the centres work as cheap hold downs in the back of the truck.
View attachment 2

 

[Grizzl-E]

Finally got some time to finish my chain drive. Ended up with a 3x3 gear system. The rear acs single speed freewheel I had on would have needed a spacer to get the chain from scraping the tire. So a couple hours on the lathe or $30 U.S. Spacer off eBay would have worked. But I just bought a 6 speed freewheel locally for $13 and swapped some of the sprockets.



Now I have a 28/16/14 accessible on the rear to 22/36/48 on the front.

And I was too lazy to machine a spacer so I just left the extra sprockets on.



Now I can pedal up to 40kph comfortably or have the mother of all granny gears and climb at 4kph if I loose my batteries.

 

[Grizzl-E]

A weak cell in my HK batteries must have totally self discharged and when I bulk charged my 18S pack it was actually a 17S pack. Long story short I went out and found my packs cells at 4.38v. I went for a ride immediately to burn off the high charge. Had the bag open ready to rip out a pack and throw it in the sand if it started overheating.

Luckily no fire and the bad parallel cells are on the end of a pack so I opened it up and will turn it into a 5S pack. It remains to be seen how much capacity remains in the remaining cells.



Uhg

 

[Grizzl-E]

Finally got these torque arms done. Made them out of 3/8 steel plate on my cnc machine that's really not stiff enough to cut whatever high carbon alloy this piece of scrap was. Next time I'm getting them laser cut, breaking a couple carbide bits gets expensive really fast.

 

[Grizzl-E]

Well it's done! And no need for a kickstand either!

In all seriousness though it's silly fast. Found 8 gauge jumper cables on sale for $10 and used them for the power and phase wires. Perfect super flexible thin strand copper and good rubber sheathing.



This frame is way to flexible for these tight fit tires. I have about 5 mm clearance on each side in the rear. Even after modifying and re tig welding the frame. I hear the nubs on these 4.8" snowshoes rub anytime I lean the tiniest bit.

That being said running 3-5 psi on the rear and 6000+ watts on snow is just insane. I have had it out on the frozen river here with 4-10 inches of snow and the front tire comes up anytime I blip the throttle. So much fun.

Any questions about it just ask.

 

[Grizzl-E]

Oh ya and these hobby king multi stars are a real lottery. Two of the three batteries each had a weak cell that I had to remove. In the same place too. That sounds like an assembly issue to me. Too much heat on the positive connection.

Anyway I'm down to 16s from 18 but that's ok. 40 kph is as fast as I've gone on snow yet and thats quick.

I put up a little video of some soldering precautions http://youtu.be/g8ZGRF2XbrE

Also I got to test my new thermal imager on the repaired batteries.



One of my cells shows its higher internal resistance.

 

[Brentis]

Sounds like fun. Wish I was closer to you so I could film ya and/or give it a rip.
Sorry to hear of your battery issues. One more example for me to stay away for HK lipo and stick with a pro built 18650 pack. Not skilled enough or interested in LiCo surgery.



Questions? Well one I guess.
Having done a lil research on FLIR. Handheld or scope mount?
If scope mount remind my to stay on your good side :wink:

Never thought I'd say it but enjoy the snow. Keep us updated.
All the best.

 

[Grizzl-E]

I got a flir one attachment for my iPhone. I have been looking for years and the resolution is as good as $5000 handhelds 5 years ago.

Ya the problem with prebuilt packs is the discharge rates. This controller pulls 80 amps battery current. I actually have 100 LG HG2 18650's sitting on my desk waiting to be made into a pack for this. But I may steal them for another project, this bike is so overkill for anything but off-road it won't see that many miles relatively. They are so tempting to use in micro packs for my other bikes cause of there high discharge abilities. And I need something to power my electric snowboard track that I'm working on.

I'll post up a ride video once the sun comes out here. Got a wearable brushless gimble for that I can't wait to try out!