Coming along nicely 2...

[tombenn444]

Hey everyone The death machine Rider here, I would like to walk you through each step of this build taking feedback as is given and considered. Got a 20" giant revive semi recumbent that's gonna be paired with a 3000w 72v bldc China motor and a 80A China controller

Okay first I was going to put the motor on the rear rack because it seemed the most obvious and convenient but I would have to sacrifice my suspension for that so im putting it down low near the bottom instead. That should help it stay a little bit more stable at high speeds cuz I'm going to need every single bit of help in that area as I can get. One thing I do not like about this bike is there's no steering adjustment to tighten or loosen the play. But it has instead is a spring that is hooked behind the fork to the frame itself I'm not sure how well this will work but we'll see. I might just have to put a bigger spring on if need be. I'm curious as to what bigger Wheels will look like with it raised up and maybe different front end but that's for another day.

Anyway,
First off, I took the rear rack plate off trimmed it up a little and made a hole for the rear shock to fit through I would like to mount the motor right in front of the suspension I might could get it behind it but it's kind of tight. The controller will fit on the rear rack and self because it's just a perfect after I get the motor mounted I'll have to run the wire through the frame then Mount the battery.

 

[Chalo]

One thing I do not like about this bike is there's no steering adjustment to tighten or loosen the play.

What does this mean? Bicycles must have very free rotating steering bearings or they won't stay balanced as you ride. There is no amount of friction in the steering axis that does anything positive for you.

But it has instead is a spring that is hooked behind the fork to the frame itself I'm not sure how well this will work but we'll see.

Usually those are fitted to cargo bikes to make them less likely to flop and fall over when they're parked or being loaded or unloaded. They're not intended to affect steering effort at all, which is why they're under little to no tension when the front wheel is pointed straight forward.

I might just have to put a bigger spring on if need be.

Don't do that. Interfering with the bike's ability to self steer back under you is a sure way to crash without even knowing why.

 

[lnanek]

On a normal bike you can loosen the stem clamp, tighten the top cap bolt to increase preload by pulling the stem down against the steerer by screwing down into the star nut, then re-tighten the stem clamp. Maybe he's complaining about no way to do that on this bike?

I have found that sometimes if I bend an adjustable stem fully out of the way and use a really long Allen wrench handle there is still sometimes a preload screw buried deep inside the joint.

No idea about this huge arm things this recumbent uses, though.

 

[tombenn444]

Funny how I can forget to post about my build while reading forums on the same topic lol. Anyway this is how it's coming. Almost done. It's runs smooth but the rear sprocket keeps getting out of true. Afraid I'm going to pop the spokes if I tighten it up too much. Need to put some conduit on the exposed wire but pretty much just little stuff. Still waiting on the rest of the parts for my battery build I'm temporarily using this lawn mower battery

 

[offGridDownUnder]

Much promise there.

the rear sprocket keeps getting out of true

Do you mean the axes don't coincide, or do you mean the sprocket wobbles so it's no longer in the plane of the wheel?

I do not know what rear hub is under that rear sprocket, but what I see suggests you may be using a 6 bolt ISO mount. Have you considered using a Gates belt and sprocket for the motor drive? I am using this on my trike (link in signature below).

I began with a chain for the rear, but I wanted regen so needed to tension it. One shop that sold track bike sprockets told me they had never known one of those to last beyond 4000 kilometres. However, the Gates system is at home in such tension, and lasts much longer as well (and doesn't care about rain).

Given that you are not tensioning the chain like that, your system may not have the problem.

I see the loaded pedal drive chain sliding over the motor casing. I will expect that to machine your motor casing over time.

 

[tombenn444]

Yeah I was going to put a tensioner or just another pulley mounted on top of the motor to keep the chain from eating through it. As for the sprocket mount what I did was I took a motorized bicycle sprocket roughly the same size and I cut it in half and I took some old tire and cut it up along with some foam padding the sandwich in between the plates then I'm mounted the actual sprocket for the bike I tried to get it as close to 90 degrees offset from the other sprocket as I could then tighten it all up. Pretty much like the standard motorized bicycle sprocket mounting way I suspect that the parts are just squeezing themselves to fit and the more I keep adjusting it it'll eventually get tight again and stay there