"Da bomb" cargo bike + Transmag 3kW / MAC 2kW / HS3548

[neptronix]

Hey, those 8mm bolts are just used as an example of how this thing slides around, can't be indexed, and does other funny stuff using 8mm bolts.

While i was out, i came up with a game plan.

I will cut 3/8" bolts down to 8.5mm by removing some of their thread.

If the threads are weakened to the point where they no longer with the bolt, then i'll drill the center of the bolt, tap it, thread another bolt through it.

This will fix the sprocket alignment issue.
It also mean i'll have a set of bolts to use with different sprockets if i chose to order from this guy again ( unlikely, but there are no alternatives at this time... )

 

[John in CR]

Just bolt it on centered. Then drill 4 new holes that match the OD of whatever bolts you find with the right unthreaded length. A fine threaded bolt will probably be fine to lock the centering too. You won't need need very thick bolts for this job.

OR

Just use some good epoxy and properly prepare both surfaces. Out at that diameter it should work, and even if it doesn't it's not a catastrophic failure since the bolts are there.

 

[John in CR]

You'll have frame flex, so since you have a rigidly affixed sprocket unlike a floating sprocket on many motos, a spring loaded idler on the slack side of the chain (maybe both with regen) will go a long way to making the chain quiet and feed the chain smoothly and properly aligned to the sprocket.

Here's what I did with a derailleur and a skateboard wheel I picked up from someone else using it as an idler, which works like a charm. Even when my wheel slipped in the dropouts and had the bike crab walking, the chain fed nicely. I think pushing outward is a benefit in this case, since there are plenty of teeth engaged.

 

[neptronix]

Thanks for the pro tip.
I do actually have a derailleur that got busted. Maybe i can put it to use for idler duty.

I'm looking at this frame more and more, and am thinking the best route forward is to sell it, including the torque plates and other bits. I wanted a high efficiency chain driven motor from the start of this quest and still want one. A Yuba Mundo, xtracycle edgerunner, or something like that is exactly what i want as a replacement. Alternately i have some ideas about a very very extended swingarm for a one of the walmart NEXT dual suspension bikes. Those are made of mild steel, so possibly i could get my crazy ideas welded up pretty easy from a local fabricator.

 

[neptronix]

Allright, so i played around with the HS3548 motor a bit more today.

Pumped the rear 2.5" moped tire up to 60 psi to minimize rolling resistance.
Swapped out the front tire for a 1.75" pumped up to 40psi.
Went to fatter phase wires.

My high speed wattage has dropped ( 4500-5000W to go 45mph is within the normal range ), but my low speed watts are still awfully high, like 1100W just to go 26mph. It should be more like 850-900 watts. Admittedly, the position is rather upright on this bike, but that's still high.

I tested the motor to see if i demagnetized it... nope. no load amps & wattage are within the rated spec, and so is rpm per volt unloaded. So there's nothing wrong with the motor.

I've got no effin' clue where the power is going. I can dump 6000W peak, 4500W continuous into this motor for quite some time, and it doesn't necessarily put that power to the road, but it also doesn't create a lot of heat. The mystery is driving me nuts

This makes me kinda miss my magic pie though; that motor was very efficient at lower speeds. Maybe it's a nature of having a high speed winding versus a low. I notice that this motor perks up at 72v versus 36v. On 36v, even being fed 80A, it feels like a small geared motor when accelerating.... on 72V, it's just stupid crazy fast from a stall to about 35mph.

Well i'm done playing around with this motor, i wanna get back to experimenting with the big MAC but i need to get rid of this frame first, maybe i'll hawk 'er on motoredbicycles forum or something.

 

[neptronix]

Well, today i went into the garage to do some other things, looked at the sprocket adapter with rage and said 'screw it'.
I am not getting any response from the seller of this crap at all, so i'm gonna try drilling it out.

Bored out the tophat adapter and sprocket to 3/8mm with a hand drill.
I actually got the holes drilled close enough that the sprocket lines up and doesn't have any 'hop' or side to side wobble on it.
Pure luck and/or a steady hand!

So yay, i now have a motor wheel with the correct offset and sprocket size to drive the MAC motor now.

I am also thinking, if i just can't sell this frame, i can have it modified to be shorter, and maybe move the motor mounts to a better position as well.

If so, i would have to rename this bike from 'the bus' to 'the short bus'.

But i would rather have an edgerunner

 

[jkbrigman]

You kicked adz on that sprocket. Congrats!

I'll share this dude's website for inspiration on your mods to "The Bus":
https://sites.google.com/site/recycledrecumbents/home
He hacks up old bikes and makes LWB recumbents out of them. I have one of his frames, he brazes all the parts together with a torch, no welding. Pretty good work.

 

[neptronix]

Ah yeah, that's cool, but those are... recumbents

Anyway i took this bike out on a 40 mile ride today. Made it 5 towns over doing 17mph with pedaling, and back on 20AH of 36V power. Not too bad i guess, that's about what my old 250w geared motor did, i just thought that this motor would be more efficient. But i would like to do this trip faster as so much time on the bike can get ya cramped up, etc.

Met up with a guy who runs a local ebike shop that had just opened recently. He had a bunch of pedegos and a few Yuba Mundos. Not too bad. Seems like he knows what he's doing. So i figured i'd say hi, and let him ride this thing on 72 volts. His comment was 'damnit, now everything i have seems slow' :lol: .... yeah. But i still like riding the MAC Trek at 25mph

I compared this frame to the Yuba Mundo, and the 'da bomb' is about half a foot longer. I kinda don't like the crazy tubing on the Yuba Mundo though, now that i look at it... but it is a better bike for carrying stuff, for certain! I kinda want one.

While i was at the shop, i had a revelation; why not just bolt some rear racks to the back of the frame? then i can hang panniers off the sides, and carry quite a bit of battery. I think i could actually have three sets of panniers.

It's not the best situation, but it does work.

 

[neptronix]

So i think i have a solution. I came up on a child seat carrier rack used for $10. It's steel and rated for 50lbs.

I can hack it up and bolt it to the support bars on the frame. Then i'll have sort of a yuba platform thing going on. Tough enough for panniers, 4sure.

Gonna try to find another steel rack at the local bike co-op, preferably in black. Then i'll have space for two panniers.

How any kw-hrs can i cram on this bike? we'll see. I ultimately want a hundred mile range at 30mph, so i can head down to Utah Lake, or head into the mountains, etc. If i want to stretch that into a longer distance at 25mph or 20mph, i should be able to do that. That's the goal, and what i've been wanting to do ever since i got into eBikes ~3 years ago.

 

[emiyata]

So i think i have a solution. I came up on a child seat carrier rack used for $10. It's steel and rated for 50lbs.

I can hack it up and bolt it to the support bars on the frame. Then i'll have sort of a yuba platform thing going on. Tough enough for panniers, 4sure.

Gonna try to find another steel rack at the local bike co-op, preferably in black. Then i'll have space for two panniers.

How any kw-hrs can i cram on this bike? we'll see. I ultimately want a hundred mile range at 30mph, so i can head down to Utah Lake, or head into the mountains, etc. If i want to stretch that into a longer distance at 25mph or 20mph, i should be able to do that. That's the goal, and what i've been wanting to do ever since i got into eBikes ~3 years ago.

You need to build a platform anyway on the back of bike. I would build it from AL or Wood and add tubing that is fastened to the platform to support bags or baskets. I would order 4 fold up chrome plated wire baskets. Then pile on the cargo. After you are loaded directly strap to the wire edge of the basket. The small cargo nets work better in my opinion because of the load is distributed over many hooks.

 

[jkbrigman]

The mounting of the rack and the use of the panniers looks good, like it "belongs" there. Your batteries should be pretty happy in there.
The balance of the bike should not suffer: even if they are a tad high, the weight is in the middle. The ride should be pretty nice that way.
Your goal of 100 miles at 30mph is my holy grail. Or at least my "Castle Anthrax". NI!

 

[neptronix]

Picked up a free dual suspension frame yesterday, so i'm thinking about the frankenbike thing again, as discussed in page #1 of this thread. The upper image is what my frame havin' sex with another frame looks like. This is the dogman way of building a longtail.

I measured how long the bike would be if i did that though, and it would be just as long as my 'da bomb', which would be perfect, if it were just a foot shorter..! So that's too long.

Now i think a good evolution on that idea would be to use the dual suspension frame as the rear chainstay of the bike. This can bring the rear in quite a bit, giving it yuba mundo length, which is pretty darn good IMHO. Not perfect, but better.

The frame pictured is a very tall 700C chromoly frame. So i'd want to experiment with maybe a shorter 26" mild steel MTB frame to see if the angle would look better or not.

I found a dude who does welding AND owns an ebike shop, who is willing to help out for a few bucks. I'm gonna rock 'da bomb' until i can get this frame situated, cuz the rear rack idea makes the bike *actually useful* for the time being.

 

[neptronix]

OK, this is what's cool about a fast cargo bike with a ton of battery on it. 15 mile trip to DHL out in the middle of nowhere and back? no problem. a section of road with 40mph traffic and no bike lane? no problem, flip the speed switch and it's a pedal assisted motorcycle capable of doing 45. Pass the road and flip the speed switch back to 20mph and pedal along as usual and it's just a bike again in the bike lane, pushing just a few hundred watts of power plus leg power for max efficiency.

This is what i set out to do 3 years ago, but didn't know it'd come in the form of a cargo bike with super fat tires.

The HS3548 isn't as efficient as the MAC for whatever reason, but it pushes the power so i'm happy for now until i figure out what the next step is.

The cargo solution is now in place - i'm using hardware store bits + a steel bar + a brace between the two bars so that hopefully, there isn't a lot of side-side motion in the panniers during turning or hitting bumps etc. haven't hooked up the panniers yet but i'm sure this will work fine
Then i can carry 22S30AH... lol.

On my travels, i also discovered what looks like a burned down space ship? or the front of a big jet? I think i discovered.... area 52...

 

[electr0n]

I'm running a similar amount of power to you. HS3540 in a 20" rear wheel, 26" front. 24s 88.8v, 80 amp battery, 190 phase. It's very quick. 8kw peak. I can pop the front wheel now if I'm not forward enough. Have you upgraded your phase wires? I just went out on a quick test to accelerate hard a few times and my stock phase wires got a tad warm.

I find it runs more efficiently in the small wheel. I also like the power band in the 20" wheel vs the 26". Acceleration and responsiveness is much improved. It doesn't have as much power between 45kph and 65kph and top speed is 20kph less but it's a good trade off.

 

[neptronix]

I'm running a similar amount of power to you. HS3540 in a 20" rear wheel, 26" front. 24s 88.8v, 80 amp battery, 190 phase. It's very quick. 8kw peak. I can pop the front wheel now if I'm not forward enough. Have you upgraded your phase wires? I just went out on a quick test to accelerate hard a few times and my stock phase wires got a tad warm.

I find it runs more efficiently in the small wheel. I also like the power band in the 20" wheel vs the 26". Acceleration and responsiveness is much improved. It doesn't have as much power between 45kph and 65kph and top speed is 20kph less but it's a good trade off.

Thanks for your report, electr0n. I bet your system is faster than mine due to the perfect combo of a lower speed wind on higher voltage plus a good amount of amps. Maybe it is more efficient than mine as well, but i am not sure.

The phase wires are upgraded to 12ga about a foot out of the motor. I never planned on taking this motor to the max, so that's good enough for me.

 

[electr0n]

Are your phase wires upgraded on the outside or right up to the windings? It would be fun to increase the voltage some more for better performance above 40kph, here your setup is probably better than mine with the faster winding. Always a trade off. I'm going to try 115% throttle and maybe adding another 5ah batteries in parallel to help with the voltage sag and give more run time.

By the way I like the cargo bike. I'd like to have something similar to take my daughter to school. She's outgrowing the trailer I've been using. Also the trailer is too wide to ride on sidewalks with pedestrians. Only thing I don't like is the lack of suspension and the price tag :lol:

 

[neptronix]

On the outside. Yeah, i did it the cheater way.

Your setup probably has more torque, but maybe suffers voltage sag which prevents higher speeds? i mean, the 3540 should be damn fast on 24S Lipo if that's what you're talking about.

The cargo bike is fantastic, but is a pain to turn around and a pain to get out of my garage door due to design. I really want something shorter. A yuba mundo with a front suspension fork tuned to be very very stiff would get you some decent suspension, since the front wheel is taking a lot more force in a setup where the rider is sitting in the middle of the bike, rather than sitting almost over the rear wheel.

For your situation, if you can forsake rear suspension, the yuba mundo frames are only $500 retail. The Boda boda, which is kind of a midtail bike, would be great as well for carrying just one person and/or a bunch of battery.

Are your phase wires upgraded on the outside or right up to the windings? It would be fun to increase the voltage some more for better performance above 40kph, here your setup is probably better than mine with the faster winding. Always a trade off. I'm going to try 115% throttle and maybe adding another 5ah batteries in parallel to help with the voltage sag and give more run time.

By the way I like the cargo bike. I'd like to have something similar to take my daughter to school. She's outgrowing the trailer I've been using. Also the trailer is too wide to ride on sidewalks with pedestrians. Only thing I don't like is the lack of suspension and the price tag :lol:

 

[electr0n]

Indeed I'm running an HS3540 on 24s lipo. My 99 volt battery drops down as low as 82 volts with a 90 amp load and 190 amp phase current. It's pretty cold out now so that doesn't help either. It's plenty fast already but it's always fun to go even faster. I think it would be fun to peel off a stoplight like the killacycle.

Even $500 for a frame is too pricey for me. I've got nowhere to store an expensive bike and I'd be even more paranoid than I am leaving it locked up anywhere when running errands with it. I'm probably going to try modifying a standard rear rack into a seat for my daughter.

Looking forward to see what you end up doing with the mid drive setup.

 

[neptronix]

Oh, haha. with sag like that, you don't even know what your top speed is :lol:

Well, if you are truly broke, check out my poor man's midtail option here.... $200 brand new from walmart, can you handle that? this would be better at carrying cargo, if you fab up a rear rack that uses the vbrake posts as attachment points.

http://endless-sphere.com/forums/viewtopic.php?f=3&t=48663

But you can't store an expensive bike inside your house or apartment?

 

[neptronix]

Well, i crashed the bike, in case you didn't read about it in this thread.

http://endless-sphere.com/forums/viewtopic.php?f=3&t=48789

Quick summary: was riding along and not paying attention. Train track at about a 5-10 degree angle appears, sucks my big 2.5" maxxis hookworm into it, and sends me flying.

The bike is okay other than a scrape on the rear rack, but i am ready to go with a taller bike which will help me hopefully see this crap in advance. I'm sellin' it for reals.

Yep.
It's 29er time.

</thread>

 

[neptronix]

The bike won't sell, so i've started to chop it up and am getting in touch with a local welder.

I am not sure if i should delete the triangulation bar or not. I won't be carrying a lot of stuff, maybe about 20-30 pounds of batteries on the rear panniers, at most. I would really like to have that space for a chain driven motor or whatnot. Maybe it can be re-angled?

This plan will take 9 inches off the frame, making it about 3 inches shorter than a Yuba Mundo - so between Boda Boda and 'Mundo length.

Why go through all this work..... well, a shorter bike will corner faster but still have that confident midtail feel. It will be lighter and less of a pain to get out of my garage, get into buildings etc. It will carry things better, and i think that if the rear triangulation bar is moved, i would have more motor or battery mounting options in that area which is a big plus.

 

[Alastor]

Man one thing i noticed form your videos is that you are in terrible need of suspension front and read.
If you do this your bike will be smoother to ride and i am sure it will improve its handling as well.

I really like your build anyhow but its stiffness its the only thing that worries me in that speeds and power.

In a race bike it should be ok but in a every day commuter might be hard on your back.Also you will enjoy the hole riding thing in a different level.

P.S.
Even a seat spot suspension will make it better to ride

 

[neptronix]

Oh!
I actually put on a super springy fat butt seat on the bike, which helps with all the vibrations that the road dishes out.
But other than large bumps, this bike is actually *more* comfortable to roll along the broken pavement etc than my aluminum Trek with a front suspension fork, if you can believe it.

One advantage of the midtail design is that the front fork ends up doing more work to even out the road. In the frame's current length though, i would think that the fork would be doing way too much work. When this bad boy gets shortened up, i think i'd feel more confident sticking a front fork on it, since proportionately, much more of my body weight would be sitting on the rear wheel.

 

[jkbrigman]

Why go through all this work..... well, a shorter bike will corner faster but still have that confident midtail feel. It will be lighter and less of a pain to get out of my garage, get into buildings etc. It will carry things better, and i think that if the rear triangulation bar is moved, i would have more motor or battery mounting options in that area which is a big plus.

Dude, it's going to be worth it. Advantages:
- it's STEEL
- the designed-in pannier rack
- you already know your crankset and freewheel work OK on it
- you could have doctorbass-style (or DIY) torque plates welded on
- you could design mounting tabs or box for battery and controller (still leaving the option for pannier batteries)
- you could have other items welded onto the frame. Mounting plates for lights, switches, fairing and even a tailbox.
- you can eliminate the paint and stickers, have it powdercoated some color you like better

 

[veloman]

Why not do it dogman style?

I am working in this one myself. Should be ultra plush.

I rode a Yuba el mundo cargo ebike today with no suspension. I don't know how anyone can deal with the bumps. Suspension is not nearly the bad thing it is on a pedal only bike.