First e-bike build thoughts and throttle only.

hulk

New Member
Region
USA
Anyone using throttle only on their bikes without installing PAS? If so, what are your experiences with it? Also, why so many members are against front motor kits? I read some of their experieces but they all had PAS installed and used it in the wet, when the front tire lost traction and they fell when the PAS kicked in.

I just installed a BAFANG 500w front motor kit and a 52V 13 ah battery in the triangle frame and I'm loving it.

yuba-mundo-7-speed-orange-M-1607OR.jpg


I also installed a basket in the front that mounts to the frame, so when you turn the handle bars the basket stays straight. I mounted the controller in the basket. The front motor is so small that from a distance you can't even see it. I thought about mounting the battery somewhere else besides the frame triangle but it just fits so nicely in there and makes the bike so stable.

YUBA-Kombi-Yellow-MonkeyBars-Basket-MiniSoftSpots_RBG.jpg




With the basket, front motor hub, and battery the bike is so stable and smooth right now it rides like a dream.

When I say I use throttle only, I mean I paddle 99% of the time and use throttle only to get up to speed or up a hill, kind of like turbo or nitrous on a car.

I have it set up to 3 levels right now, which brings me to my next point which is why the need for more than 500 watts if you want to use your e-bike like a regular bike and not a moped?

Just with throttle without even paddling, the bike does:

Level 1 - 8mph
Level 2 - 15mph
Level 3 - 23mph

And this is with me (almost 200 pounds and my 7 year old on the back, probably another 40 pounds). I only went 23mph with her for a few seconds before backing off. Also, I don't know if it's because the bike weighs so much or that the front motor kit makes the wheel turn better or what, but this bike rolls forever....if I hit the throttle and go up to 20mph and turn the throttle off and stop paddling the bike will just coast what seems like forever, at least 1/2 mile or so. I don't feel the weight of the front motor kit when paddling on flat ground but on a slight incline I can feel the drag just a bit, but the drag doesn't feel that bad, it's hard to explain, I feel like a rear hub motor would have a different feeling, like you were dragging a dead weight. But just a slight touch of the throttle gets rid of the feeling.

I think 500 watts is the sweet spot. Before Covid I traveled on vacation to Italy and France and there I rented e-bikes which have the standard 250w motor. I thought they were fun for the first 5 minutes....they top out at 15mph! 15mph is way to slow but 20-23mph (or even 25mph with some hard paddling) is the sweet spot. I feel like anything more is just not needed. By the time you speed up you have to slow down again because of stop signs, lights, or even regular streets where the other side has a STOP sign but you have to slow down anyways since so many people run STOP signs.

I do have one question, before I got the motor kit my bike would top out at about 18mph in 7th gear (bike has 1 x 7 gears) no matter how hard I paddled (I think the term is "spin-out"?)

My current rear cassette is SRAM 14-28. I really like this gear because prior to getting the motor kit I used to go up this one giant hill that was so steep I had to be in first gear going up at 2mph on it ( same hill with the motor I was doing 15mph on and took me about 10 seconds to get up instead of like two minutes)!

Anyways, the bad thing about the rear cassette is that it tops out at 18mph....so now when I turn the e-bike on and use the throttle and go over 19mph I don't feel like my paddling is adding any energy to the bike.

What kind of rear cassette do you guys recommend? I would like to paddle up to, say, 20-22mph when using the throttle and feel like I am putting energy in.
 
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Marci jo

Well-Known Member
Where’s the motor on your bike? In the front wheel?
Side note: “Paddling“ is the action in a boat or canoe. “Pedaling” is the action on a bicycle. Lessons from 6th grade English class.
 

ElevenAD

Well-Known Member
Anyone using throttle only on their bikes without installing PAS? If so, what are your experiences with it? Also, why so many members are against front motor kits? I read some of their experieces but they all had PAS installed and used it in the wet, when the front tire lost traction and they fell when the PAS kicked in.

I just installed a BAFANG 500w front motor kit and a 52V 13 ah battery in the triangle frame and I'm loving it.

View attachment 94735

I also installed a basket in the front that mounts to the frame, so when you turn the handle bars the basket stays straight. I mounted the controller in the basket. The front motor is so small that from a distance you can't even see it. I thought about mounting the battery somewhere else besides the frame triangle but it just fits so nicely in there and makes the bike so stable.

View attachment 94736



With the basket, front motor hub, and battery the bike is so stable and smooth right now it rides like a dream.

When I say I use throttle only, I mean I paddle 99% of the time and use throttle only to get up to speed or up a hill, kind of like turbo or nitrous on a car.

I have it set up to 3 levels right now, which brings me to my next point which is why the need for more than 500 watts if you want to use your e-bike like a regular bike and not a moped?

Just with throttle without even paddling, the bike does:

Level 1 - 8mph
Level 2 - 15mph
Level 3 - 23mph

And this is with me (almost 200 pounds and my 7 year old on the back, probably another 40 pounds). I only went 23mph with her for a few seconds before backing off. Also, I don't know if it's because the bike weighs so much or that the front motor kit makes the wheel turn better or what, but this bike rolls forever....if I hit the throttle and go up to 20mph and turn the throttle off and stop paddling the bike will just coast what seems like forever, at least 1/2 mile or so. I don't feel the weight of the front motor kit when paddling on flat ground but on a slight incline I can feel the drag just a bit, but the drag doesn't feel that bad, it's hard to explain, I feel like a rear hub motor would have a different feeling, like you were dragging a dead weight. But just a slight touch of the throttle gets rid of the feeling.

I think 500 watts is the sweet spot. Before Covid I traveled on vacation to Italy and France and there I rented e-bikes which have the standard 250w motor. I thought they were fun for the first 5 minutes....they top out at 15mph! 15mph is way to slow but 20-23mph (or even 25mph with some hard paddling) is the sweet spot. I feel like anything more is just not needed. By the time you speed up you have to slow down again because of stop signs, lights, or even regular streets where the other side has a STOP sign but you have to slow down anyways since so many people run STOP signs.

I do have one question, before I got the motor kit my bike would top out at about 18mph in 7th gear (bike has 1 x 7 gears) no matter how hard I paddled (I think the term is "spin-out"?)

My current rear cassette is SRAM 14-28. I really like this gear because prior to getting the motor kit I used to go up this one giant hill that was so steep I had to be in first gear going up at 2mph on it ( same hill with the motor I was doing 15mph on and took me about 10 seconds to get up instead of like two minutes)!

Anyways, the bad thing about the rear cassette is that it tops out at 18mph....so now when I turn the e-bike on and use the throttle and go over 19mph I don't feel like my paddling is adding any energy to the bike.

What kind of rear cassette do you guys recommend? I would like to paddle up to, say, 20-22mph when using the throttle and feel like I am putting energy in.
If your spinning at 18mph it could be cheaper for you to just replace the front chainring with something a little bigger! What size front chainring are you using now?
 

indianajo

Well-Known Member
My yuba bodaboda has a 11 to 32 8 speed sprocket set. With 32-42-52 front I can go 1 mph unpowered up 15% hills, or I can keep up with the motor @ 25 mph. I don't help much at 52:11. Unpowered is important, as the throttle can fail in the rain. Happened 7/12, had a plastic bag over the throttle but the rain was so hard it burned the pin off the ASI controller for the MAC. Pedaled unpowered 20 miles to summer camp then 30 miles home the return trip. Still waiting for a new controller ordered 7/14.
I have a front motor. Was ebikeling 1300 W geared hub (wore out gears 4500 miles), then until 2 weeks ago Mac12t 1000 w. The higher wattages don't really add much torque, they just heat the motor up faster. 500-700 w is about the most efficient up steep hills. I have the battery hung off the front as you do. I built a 5" wide box for the battery instead of the yuba bread basket that is 14" wide. You can see the back of it in my avatar left. It is lined with foam blocks from the battery shipping box, with a green plastic bag over it. I use knobby front tires, 2.1" kenda or giant. They get less flats than road tires, like every 2 or 3 years.
I determined I hated ebikling PAS when I had that motor on the front of a huffy Savannah cruiser. It had a minimum acceleration of 500 W, which was dangerous if PAS kicked in while I was turning sharply or riding on my rutted grass driveway. I didn't move the PAS pickup when I moved the motor to the yubabike, bought 12/17. I use throttle only.
The front could still fall down on wet or muddy steel plates (contruction zones), wet wood bridge decks (never happens here) or ice. The tort lawyers of USA drool at the thought of yuba selling a front motor bike. A fall with a kid in a carrier on the back, what a windfall!. 30% of a million dollars! I simply don't use the motor in those situation. In fact I walk the bike over the muddy plate in the contruction zone. I have a brain & use it. As a result I have a nicely balanced bike instead of the rear heavy slug it was when I first had a 1000 W direct drive motor on the back.
BTW the nice thing about a converted bike, you can use the extra wire harness to the motor to make a loop to it under the wire ties. So I can change the tube without unplugging the motor; just cut some wire ties & lay the wheel on the ground. I flip the bike upside down to change tubes, I deleted the display. Just a voltmeter in the throttle.
BTW this week with the front motor & battery removed, the bike won't stand up on the dual leg stand even with just tools, water, tubes & rain gear in the panniers. The front lifts in the air & the bike falls over. I carry 60-80 lb of groceries & ag supplies out to my summer camp weekly. Had 8 liters of soda & 2 1/2 gallons of weed killer home from the store yesterday.
 
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ElevenAD

Well-Known Member
Where’s the motor on your bike? In the front wheel?
Side note: “Paddling“ is the action in a boat or canoe. “Pedaling” is the action on a bicycle. Lessons from 6th grade English class.
How do you know this dude even went to 6th grade in this country? He is on a bike forum trying to get some help, not in school so chill the eff out.
 

m@Robertson

Well-Known Member
Region
USA
There's nothing wrong with a front motor per se. What is wrong comes from how people who haven't thought through the job install them. Thats where the outright hate comes from. The internet is literally filled with pictures of forks with snapped dropouts where the front axle caused them to fail. Torque arms are essential to keep this from happening, but the plot is complicated by the fact that amateurish efforts on that front can also fail spectacularly. At best in those circumstances the torque arms just hold the wheel in place in the snapped dropouts for long enough so the rider doesn't faceplant.

So how do you avoid the issues? 1: Use a steel front fork. The more substantial the better. 2: Don't use an alloy fork. Steel bends but alloy snaps and its not as strong in a small place like dropouts. 3: Never ever use a suspension fork; especially one with alloy dropouts. Not only can the dropouts snap, no fork ever was designed to be pulled upon and a 2-pc fork blade can flex and pull itself apart. 4. Always use a torque arm and 5: Two torque arms are better than one and so what if it makes the wheel tougher to remove. I learned the hard way ruining a steel fork on my very first install where the dropouts *spread* because I had a kaka torque arm that let the axle rock just enough to start it on a roll.

So we used a steel fork and we put on two torque arms, even though a 60Nm motor isn't all that powerful and two is overkill. Great. Now what? Front power coming on hard to the front wheel is a real issue. Again on that small Bafang its probably not *much* of a problem, but safety should be addressed nonetheless. If you have a KT controller - and I use them on all three of my front hub motors - there is a setting to use full current/amperage on the motor, but roll the power on slowly. This happens for PAS and throttle in equal measure, so its not possible to throw yourself into traffic or fall on your face if you engage PAS from a stop and forgot to point your wheel straight (my 80Nm fat hubs will do both).

For your small Bafang hub, I would be more focused on making it perfectly-mannered and a slow start setting will do this and address any potential safety issues. As for torque arms, you may get away without one on that smaller motor but once you ruin a fork at the least the fork is unrecoverable and that is a real pain in the ass. Eliminating the possibility is cheap insurance and ensures you are riding the bike home, not carrying it.