E-ASSIST not throttle rocket!

I am a NOOB! I just read a post on types of e-bike systems. Instant start and delayed start? I can't remember the name of the second system but you pedal till you get to 5mph and then the motor takes over. Are those the only options? I would have asked the guy who posted but it was locked.

I have a Catrike Dumont and it weighs 42lbs and I weigh between 250 and 260. I like pedaling I bought the bike for exercise. I just need some help because I have already gotten tendonitis staining on those pedals. I can get up most hills... sometimes at 3-6mph. Which I noticed was slightly slower than a man casually walking his dog.

So #1.I have my bike to convert. Catrike Dumont I have modified it with a Patterson 2speed crank and a Shimano Alfine 11speed rear hub. Since I am secquencially challenged I absolutely need to keep the rear hub. Forget to downshift... I really like the Patterson but can ditch it if a mid drive can help me up hills. Most mid drives have a 45t chain ring where as my Patterson has 45-28t virtually. (The high range 175%) I talked with Chistoph at Grin and he suggested front hub motors or motor. One hub motor on the front of a bike with front suspension doesn't sound like a good idea (imbalance) but he said 2 would be expensive and complicated. I could keep all my mods though.
#2 Speed faster than a guy walking his dog. Seriously 20mph max under power. Can I turn it off coasting downhill?
#3 40-60miles would be good for how much battery. I do have steep hills on my regular loops.

I don't need another hobby so I don't want to get a degree in electronics just to electrify my trike. Any book suggestions or help would be greatly appreciated.

PS I did look up a post on books here for E-Assist.

I am a NOOB! I just read a post on types of e-bike systems. Instant start and delayed start? I can't remember the name of the second system but you pedal till you get to 5mph and then the motor takes over. Are those the only options? I would have asked the guy who posted but it was locked.

I have a Catrike Dumont and it weighs 42lbs and I weigh between 250 and 260. I like pedaling I bought the bike for exercise. I just need some help because I have already gotten tendonitis staining on those pedals. I can get up most hills... sometimes at 3-6mph. Which I noticed was slightly slower than a man casually walking his dog.

So #1.I have my bike to convert. Catrike Dumont I have modified it with a Patterson 2speed crank and a Shimano Alfine 11speed rear hub. Since I am secquencially challenged I absolutely need to keep the rear hub. Forget to downshift... I really like the Patterson but can ditch it if a mid drive can help me up hills. Most mid drives have a 45t chain ring where as my Patterson has 45-28t virtually. (The high range 175%) I talked with Chistoph at Grin and he suggested front hub motors or motor. One hub motor on the front of a bike with front suspension doesn't sound like a good idea (imbalance) but he said 2 would be expensive and complicated. I could keep all my mods though.
#2 Speed faster than a guy walking his dog. Seriously 20mph max under power. Can I turn it off coasting downhill?
#3 40-60miles would be good for how much battery. I do have steep hills on my regular loops.

I don't need another hobby so I don't want to get a degree in electronics just to electrify my trike. Any book suggestions or help would be greatly appreciated.

PS I did look up a post on books here for E-Assist.

I'm not sure we have what you want here. The thing for you might be to get yourself to a local mechanic/retailer who takes an interest in these matters. From here, A&B Cycle looks like a good bet.

Here, you're going to get a lot of discussion that goes every which way and will be hard to accurately sort out. The only thing I'm going to try to say about it myself is, the throttle is your friend.

Some people seem to get the idea that it's more virtuous to control the motor by pedal action, instead of a throttle. That's OK if it's what you like, but it's just another type of throttle, just very limited. If you have an ordinary throttle, it's up to you when and how you use it. The advantage is that you can use it when and where you need it.

My bicycle is a recumbent, like your tricycle, and I can't stand on the pedals, so the regular big loads that strain my knees are the starts, particularly of course if I wasn't in a real low gear when I stopped. If I could use my electric motor for one thing, it would be for starts. That's exactly where the PAS (Pedal Assist System) crank controllers don't work so well, from what I've heard. Or I want to cross an intersection in a hurry, etc. For most riding, my controller has a "cruise control" feature that I set at usually a fairly sedate pace.

You will likely be presented with the option of a PAS system, and you might turn out to like it, many do. Often they come with a throttle, too, and I'm just saying, don't be surprised if you find that it's a good thing to have that direct control over the motor.

A BBS02b or a TSDZ2 mid drive motor would work best if you want to keep the Alfine rear hub. The TSDZ2 has torque sensing and can be set up so it just seems you're pedaling on flat ground even when going uphill. There is great support here on E-S for this drive with custom open source firmware to make it even better:https://endless-sphere.com/forums/viewtopic.php?f=28&t=79788

https://github.com/OpenSourceEBike/TSDZ2_wiki/wiki/FAQ

https://github.com/OpenSourceEBike/TSDZ2_wiki/wiki


[youtube]L6YKhIHyns8[/youtube]

jq4eskimo said:

I don't need another hobby so I don't want to get a degree in electronics just to electrify my trike. Any book suggestions or help would be greatly appreciated.

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Hard to not be a hobby, even just from a safety perspective, unless you purchase something off the shelf (production bike/trike). The best thing to do is to buy a complete kit with battery so you don't need to break out the soldering iron, or having extreme luck, getting the components mated together.

With the biggest battery, this one looks to run around $1100 or so, depending on the options selected:
https://em3ev.com/shop/bafang-48v-750w-bbs02-kit/

Thank you very much for all the feedback. I have never even ridden an electric bike. So I don't know what the whole experience is about. I could use help sprinting across intersections as it seems at some lights I am sweating to get through before the light turns red. I will address each poster separately now. Thank you.

Well, in some ways the easy thing to do is to replace the rear wheel. This may be requiring you to change your rear shifter to a 7 speed, so the bike is now compatible with a 7 speed rear gear, which is typical with wheel motor kits. Don't worry!!! With that motor to help, you won't be needing more than 3 of those gears. Seriously! You will just put it in the gear you like best, say 18-20 mph, and then leave it there till you get to a seriously steep hill. Biggest cog you will want in back is about 28 teeth. Very likely you will leave in on 14 or 16 tooth rear gear, almost permanently.


Any bike shop can change your shifter for you. Then it just takes more or less, the ability to take your wheel off the bike and change a tire, to install a kit. you will need to carry the battery someplace, and on tadpole type trikes adding a rear rack is the simplest solution. Again, a bike shop can install one for you if you need that done.

Get a rear wheel, internal planetary gear type motor. This type of wheel coasts down hills like normal, no need to turn it off. But if you wish to turn it off, the bike will pedal like normal, just a bit heavier. Mid drives btw, freewheel similarly if you choose a mid drive.

Control the motor with a throttle. Despite many advances, your brain is still a quicker computer than most systems, and all affordable ones. Pick a speed ( pedal cadence) you like, then vary the throttle continually to get the effort level you want. Don't throttle to a speed, then try to catch up with pedals in too low a gear. At the stop sign on a hill, just throttle till you reach the speed of the gear you are in, then pick up pedaling. No strain on tendons. In practice, it works great to throttle to 10 mph, start pedaling then, and then back off the throttle when you get to your favorite pedal cadence.

Range varies with how much assist you use. But 30 miles from a typical 48v 15 amp hour battery is quite possible, at speeds under 20 mph with moderate pedaling effort.

It's true that if you have a motor, as long as the battery is good, gear shifts are less important, so it will be easier to get along without the Alfine. Until the battery runs down. Personally, I do shift quite a bit, but the point is I don't strictly need to, so if I'm stopped in high gear, that isn't a real problem. (I have almost completely stopped using the front derailleur, though.)

With the Alfine on there, your options are few. That's why Grin proposes a front hub - it's the only thing that makes sense. And it's a simple, economical solution that will work fairly well. I'm sure they know that from experience. What I've read about that, is that while there obviously is an imbalance, pulling from one side, it's easy to get used to and not a big problem.

I tried posting yesterday and admin said I couldn't cause it was to soon. Trying again...
Thank you to everyone who posted! Among the valuable things I am getting from your comments is the experience of riding with E-assist. There are a lot of YT vids that are very helpful but no one says anything about shifting. I like riding my trike I got it for exercise and have put over 3000mi on it since I bought it in '18. I want to feel like I've done a good work out.

SlowCo: I have considered a Tongsheng middrive. I watched a lot of Tim's YT vid which were helpful. It would solve the imbalance issue. I would lose my Patterson but keep the Alfine.

2 Questions in general independent of what system I choose:
1.With all of my options I would be pushing the Max weight limit. Do manufacturers state a lower weight to cover their butts or is this a serious consideration?
2.Is there a calculator or rule of thumb (I looked at Grin's motor calculator and got that "You gotta be a rocket scientist vibe" that tells how much Motor/Battery I would need for my Bike/Rider overall weight of est. 320lbs?

Battery range ??? That is the holy grail and as controversial as one's religion and or political views.

It all comes down to how much mass one is trying accelerate and sustain at a given speed. Wind resistance starts to become a factor above 10MPH and a huge factor above 20MPH. The recumbent has a bit of an advantage in that regard.

A good road bike will weigh less than 20 pounds ... an expensive one can weigh less than 16.
Typical cruisers or mountain bikes will be around 30 pounds plus or minus 5 depending on many factors.
A common EBike will be between 45 to 75 pounds with the more powerful big battery 'hot-rods' and cargo bikes going up over a 100 pounds.

A typical rider is around 150 pounds with the more vertically challenged somewhat less and the more robust somewhat more. So call the average weight for a rider and E-bike around 200 pounds. For a rule of thumb for an average combination of rider and bike I figure 1 mile per amp hour for a 48 volt battery ... but I am very conservative. That means that the rider does not contribute much energy, does not ride over 25mph and that the battery has to meet that performance level for 3-5 years.

Decrease your speed or mass or pedal more and that number goes up.
Increase your speed or mass or pedal less and that number goes down.

Also remember that an extra five pounds of battery may be a huge factor for lightweight rig but on a heavier combination the mass difference is barely noticeable.

One more thing ... do not ever believe the Ebike's manufacturer's range estimates ... the marketing propaganda is based on going downhill under optimum conditions with a brand new battery hot charged to the max.


oops ... I did not mention battery chemistry. Unless otherwise indicated assume any Lithium Ion battery is Lithium Cobalt Oxide (LiCoO2). Least expensive with average performance per unit mass. Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) (aka NMC) will get you bit better performance but cost a tad more. Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) (aka NCA) will get you the highest performance but a bit less safe. Lithium Iron Phosphate (LiFePO4) (aka LFP) has less performance than Lithium Cobalt but has a far longer life expectancy and safer. If a manufacturer/vendor is unwilling (or worse unable) to reveal their cell chemistry then run away.

... and for anyone who might be interested I have uploaded my XLS spreadsheet for Lithium Ion Batteries. Includes separate sheets for all the cell chemistries listed above. http://www.keywild.com/X/Litium_Battery_Pack_Calc_Sheet-xls.zip

jq4eskimo said:

SlowCo: I have considered a Tongsheng middrive. I watched a lot of Tim's YT vid which were helpful. It would solve the imbalance issue. I would lose my Patterson but keep the Alfine.

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You'd lose both. Or rather, you'd put the Patterson aside, and you'd really lose the Alfine. The crank drive will deliver 10x the power of your legs, and even if you weren't pulling a heavy load, that hub isn't built for that kind of punishment. You'll break it. A lot of people like crank drives, you might too, but don't tie one into an expensive delicate drive line - get an inexpensive sprocket+derailleur on the back.

Well now ain't that a bolt of lightning!?! Sounds like it would be an awful harsh ride. I have heard that electric motors have instant torque, no way of letting those x's go one at a time and not all at once? So Utah trikes show mods where they match a Bafang with a Rolhoff. Now I know the Rohloff is good but is it that massively much better?

Some thoughts you may find useful:

jq4eskimo said:

I want to feel like I've done a good work out.

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For that, you may want something that detects how hard you are pedalling, and provides assist based on that. There are a few ways of doing this, but some of them are incompatible with other things you may want, or may require more DIY than you want to do.

I have considered a Tongsheng middrive.

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If you pedal hard, or a lot, these are not presently a good option--their crankshafts have a serious design flaw that causes them to break off while pedalling. There's a number of threads about it, and some people have been trying to design a new crankshaft that can be installed, but it isn't solved yet.

1.With all of my options I would be pushing the Max weight limit. Do manufacturers state a lower weight to cover their butts or is this a serious consideration?

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For this, I'll repost basically what I said in someone else's recent thread: Weight limits don't matter as much if you are riding on completely flat perfect roads. The problems happen when you ride on bumpy surfaces, especially ones with jolting holes and whatnot. Each time a wheel drops and hits, or bounces up on a rock or piece of road debris, the whole frame twists, axles bend, etc. with forces created by the weight multiplied by the g-forces involved. It's unlikely anything will break off immediately...but stress damage builds up, and especially with aluminum can being to stress-fracture and eventualy just snap off. (where steel stuff tends to bend first, giving you an easier chance of seeing something is wrong before it breaks).

Whether any particular manufacturer uses a CYA limit or the actual limit, you would have to find out from them (and they probably won't answer usefully).


FWIW, this is why a lot of cargo racks and baskets break, even though they aren't carrying a full load of weight vs their "rating". The vertical cyclic loading from bumps and potholes, as well as the lateral cyclic loading from "tail wag" during pedalling, eventually fractures them, usually at the mounting or interconnect points.

2.Is there a calculator or rule of thumb (I looked at Grin's motor calculator and got that "You gotta be a rocket scientist vibe" that tells how much Motor/Battery I would need for my Bike/Rider overall weight of est. 320lbs?

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There's no simple calculator; it depends on your specific riding conditions and usage, as well as exactly what you use for the motor, controller, etc., to tell the right battery for the needed range, etc. But guesstimates can be made from general experience. With steep hills and a lot of weight (adding more for the electric stuff), it takes a lot of Wh to do the work.

Assuming no pedalling (to be sure the system can do what you want and give range you want), and given the weight and "steep hills", without detailed info on the actual terrain and conditions, I'd guess you could use 50wh/mile (or more). 60 miles at 50wh/mile, or 60 x 50, is 3000wh. That's around 50lbs of battery, around the size of a typical schooler's backpack. If your conditions take more power then you need more battery (which increases your need for power which increases your need for battery, because of the battery's own weight).

How much power (watts) it takes a motor for to do what you want will depend on the specific slopes you need to climb, and the speed you need to climb them at, and the actual total weight. The steeper the slope, the more power. The higher the speed, more power. The higher weight, more power. Without specific numbers, you can't get a specific answer.

A hubmotor system will take more power to do the same thing as a variably-geared middrive that goes thru your pedal drivetrain, for slow hill climbs the hubmtoor will create a lot more waste heat because it can't be kept at the optimal motor speed for the load, whereas the middrive can be kept closer (as long as you shift gears properly for it).

jq4eskimo said:

I have heard that electric motors have instant torque, no way of letting those x's go one at a time and not all at once?

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That is where a throttle comes in handy, whether it is operated by your hand, or as a control input from how hard you are pedalling.

Weii thank you to everyone who made comments. I think I got all my questions answered. So I will not be monitoring this thread anymore.
Thank you
jq4eskimo