Target: 35Mph, Trek 820 Frame, 36 OR 72V. What would YOU do?

General Discussion about electric bicycles.
Winstonk24
1 mW
1 mW
Posts: 17
Joined: Sep 09, 2016 5:23 pm
Location: Florida

Re: Target: 35Mph, Trek 820 Frame, 36 OR 72V. What would YOU

Post by Winstonk24 » Oct 20, 2017 8:56 pm

I have a trek 7.5fx and i cruise at 30mph daily for 20+ miles for over a year now. Idk how many miles i have but im guessing at least 5000 and i have had 0 issues... With a full charge and the wind to my back il hit 34ish. Just watch your temps.

Mac 10t
50v em3ev triangle battery
40amp controller

So yes it can be done. Yes you have to watch out for every bump and everything that might be on the road. I have had some close calls running over some things that definitely scared me. I think the scariest was a 2 by 4 at 30....

Voltron
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Posts: 1440
Joined: May 02, 2013 4:53 pm
Location: Santa Barbara CA

Re: Target: 35Mph, Trek 820 Frame, 36 OR 72V. What would YOU

Post by Voltron » Oct 20, 2017 9:12 pm

That's what I meant in the previous post.. things come up at you fast at 30+... and if the bike doesn't naturally want to ride right over them it can get sketchy. Frame integrity aside, bump induced speed wobbles or airtime aren't fun, on road anyhow.

Pyrotrons
1 mW
1 mW
Posts: 12
Joined: Sep 09, 2017 11:12 pm
Location: Houston, Texas, United States

Re: Target: 35Mph, Trek 820 Frame, 36 OR 72V. What would YOU do?

Post by Pyrotrons » Dec 30, 2017 6:33 am

Hi All,

Well, this project has taken an interesting turn. Initially I was limited to either a 36 or a 72V battery because of the source... "alarmhookup" on Ebay. He was known for his Samsung 2200mAH cells and the purple 36V 4.4AH modules. Well I waited too damn long to buy from him and, well, I kindof dropped a lot of money on a LunaCycle 60V 20AH battery + charger. I think it was the right decision... not only is it a substantial and "DONE" battery, but rigging ten different modules together plus designing "reverse diodes" onto a PCB would have been another thing getting in the way. The challenge has moved to designing a battery enclosure... probably will be 1/8" Al plate cut on the band saw then TIG'ed together. Dunno yet how to mount to the bike because I simultaneously hate clamps *and* drilling the frame.

Here's the setup now... All parts are ready except the eBike controller!

2001-ish Trek 820
Homemade eBike controller!! Parts come in tomorrow :D
https://endless-sphere.com/forums/viewt ... 0#p1347370
LunaCycle 60V 20AH battery
"Voilamart" "48V" "1000W' motor. I plan to fill this with ATF and rewire the leads with the biggest magnet wire I can find...
E.R.T. 3kW sine wave controller

I promise to not ride it as fast as it will go.

How fast do you think it'll go? In with that question is "What the hell kind of motor comes with the Voilamart kit?" Ya'll I've searched and searched, I have no clue what speed the windings are wound for. Anyone know?

Pyrotrons
1 mW
1 mW
Posts: 12
Joined: Sep 09, 2017 11:12 pm
Location: Houston, Texas, United States

Re: Target: 35Mph, Trek 820 Frame, 36 OR 72V. What would YOU do?

Post by Pyrotrons » Feb 05, 2018 4:22 am

Hi All,

Don't judge me, I normally don't stand for anything but high quality work, the whole platform will change soon. I prefer a custom TIG-welded Aluminium battery container as opposed to a bag and a microcontroller in direct contact with my legs. For the time being I'm riding this thing :) Ignoring the thrown-togetherness, I'm on Cloud 9... the power, speed and silence has FAR exceeded my expectations and it just gets better from here. I'm looking forward to soon having something that's operational and also NOT a death trap. The project is now:
  • Trek 4500 with a seized front fork and no back disc :roll:
  • Voilamart "1500W" motor. Dirt cheap, runs great, putting ferrofluid in it soon because why not.
  • Lunacycle 60V battery (66V fully charged, 20AH) Ton of power. Couldn't be happier with their product.
  • Homemade E-bike controller.
  • E.R.T. 3kW sinewave motor controller. Silent, smooth, and just WORKS. Super happy.
  • No torque arms yet, it's a terrible decision to ride it right now, the CNC-plasma-cutter guy will have them soon
  • Programmed limits keep the motor from spinning out of its mount
Top speed is far, far faster than I want to ride this thing right now, but I'll admit to doing a controlled downhill run to 40MPH. At about 50% throttle and ~1700W it's going 35MPH. I think I can see a few sides of the coin. The pothole-conversation is highly situational, and nuanced...in my case, I simply DONT hit the potholes because I put 4K miles on the route last year and I know exactly where they are. Given 4,000 miles of previous low-speed experience and a well-known route, a hardtail @ 30MPH is just not going to be an issue. At all. However, had I started out this way, I can see major injury.

I bought a full-suspension bike for $80 yesterday, for the purpose of feeling like an idiot when my eyes landed on the big spring where the battery goes :roll: I don't know what I'm going to do. Probably re-sell it to get my 80 back, sell the Blue Trek 820 that's part of this thread, shell out a couple hundred and buy...what? What $400 FS bike am I gonna buy that will fit a triangular Lunacycle 60V? I'm a little worried, but I can stick with hardtail 30MPH discomfort.
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