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I want to build an E-cruiser Newbie

Ozzietx

1 mW
Joined
Apr 15, 2024
Messages
10
Location
South Texas
Brand new guy here. I am interested in building a cruiser style e-bike. Would the collective be willing to verify my sanity and safety. I want to go with a steel frame for the flex and durability. I’m not super concerned with weight.
I am attempting to keep the base bike frame reasonably inexpensive. I am considering the Retrospec Cruiser 29.
Unfortunately, it is not available with disc brakes. I really do want to go with disc brakes on this bike.
I would need to convert it to disc brakes. I am considering the following components:

I plan on using the CYC X1 pro for power

And will use this battery

Does this seem plausible, or am I missing gaps in my knowledge or sanity. I appreciate any helpful input.

The bike will be used as a commuter bike, as we travel around the country in our RV.
 
I would pay a bit more for the base bike and start with a Micargi Seattle 7 speed and go with a rear hub motor, which would balance out the cost.

That Cyc X1 is expensive and will eat your drive train components. Mid motors that rely on a rear derailleur are also more difficult to ride, because you need to concentrate when you change gear.

If you are new to e-bikes then I would advise staying away from the CyC.
 
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I would start with a Micargi Seattle 7 speed and go with a rear hub motor. That Cyc X1 will eat your drive train components.
Thanks for the input. That is quite a bit more than I wanted to spend on the base bike. I’m hoping to keep it between $250 and $350. Also, I think I would prefer 29” wheels vs 26” wheels. I like the look, and am thinking they might give better handling.
I also really like the torque sensing feature of the CYC system.
 
Disk brake adapters have a really bad rep as being fiddly to adjust and weak compared to frames designed for disc brakes, and that's a scary thought for a safety part like your brakes.

I think I'd just take any used cruiser with discs off Facebook marketplace for the same cost rather than buy new and try to adapt. My wife's Electra Townie Path 9D has very competent hydraulic disc brakes in a cruiser frame and I see them go for $250 used all the time. It's 650b rather than a 29er is all.

Personally I just have an ancient 90's hard tail hybrid that I put riser bars/stem on instead of flat bars and it's the same seating position as a cruiser at that point anyway:

Still has 700cc wheels that have similar roll over ability to 29ers. I use a Nexus IGH roller brake in back to avoid adapters there:

And the fork came factory ready for disc brakes as well as rim.
 
If you "need" disc brakes (you don't, but you need better brakes than a single coaster brake), then start with a bike that has them. If you want to use a crank motor that is configured for a threaded bottom bracket shell, start with a bike that has one of those. There are ways around these things, but they don't amount to a noob project.

My latest e-bike is an Electra Cruiser conversion, but it was a surprisingly complicated job despite being a simple bike to start with, because I had special requirements. Electra Cruiser 7 with a 7 speed rear hub motor is a good approach for a first e-bike project. What you are discussing isn't.

I'll note that RV life sounds like it might involve a lot of lifting and stowing your bike, and a typical cruiser is both quite a bit heavier and longer that most other bikes, and more difficult to attach a battery to. So it would be a good idea to look for a cruiser with an aluminum frame and luggage rack mounts, which would be lighter and more adaptable than a typical cruiser. Or if you sacrifice the beach cruiser look, you can get a lighter bike that's much closer to plug and play for e-bike conversion.
 
The Cyc motor also isn’t designed for a single speed bike so you will also have to sort out a derailleur for the base bike you have chosen, or run it on a single speed with risk of damaging the motor.

Also it doesn’t look like the bike you have chosen has a threaded bottom bracket, so a threaded adapter will be needed for the cyc motor.
 
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I really appreciate the responses. I clearly still have some learning, and research to do. Does anyone have a recommendation for an inexpensive cruiser frame that’s already set up for discs and a derailleur? I know inexpensive and durable generally don’t go hand in hand.
Just hoping I can find a decent frame at a good price since I will be changing most of the hardware out. Would a 26” cruiser fit my storage rack more easily, or should I consider starting with a MTB frame? I was looking at cruisers for a smoother more stable ride. Is that incorrect thinking?
 
Don’t rule out buying a ready built e-bike. By the time you have bought a bike and modified it properly, the cost could be close to a prebuilt bike.

And also do some research of the advantages and disadvantages of hub versus crank drives before buying anything.

They are vastly different animals and you may find a hub drive will suit you better than a crank drive.

I use a mid drive solely for off road use and a rear hub drive solely for road use.
 
What are you trying to accomplish with disc brakes? You can get equal or better braking from rim brakes, with less chance of damaging them while loading and unloading. And that goes triple when you're limiting your choices to ultra cheap bikes. Bottom of the barrel disc brakes are total garbage, very weak and troublesome. They're only made to resemble brakes, not to work as brakes.
 
Bargain basement disc brake bikes often come with cable operated disc brakes which I have found to be useless for actually stopping the bike.
 
Don’t rule out buying a ready built e-bike. By the time you have bought a bike and modified it properly, the cost could be close to a prebuilt bike.

And also do some research of the advantages and disadvantages of hub versus crank drives before buying anything.

They are vastly different animals and you may find a hub drive will suit you better than a crank drive.

I use a mid drive solely for off road use and a rear hub drive solely for road use.
This may seem silly, but I really don’t care for the styling on most per-built e-bikes until I get into the $5k plus arena.
I will do some more research. On crank vs hub drive. Maybe I jumped to the crank drive too early. This will be primarily for road/sidewalk use.
 
What are you trying to accomplish with disc brakes? You can get equal or better braking from rim brakes, with less chance of damaging them while loading and unloading. And that goes triple when you're limiting your choices to ultra cheap bikes. Bottom of the barrel disc brakes are total garbage, very weak and troublesome. They're only made to resemble brakes, not to work as brakes.
Maybe I have an incorrect view of disc brakes. I thought that they would provide better stopping power, especially in damp/wet conditions. Is my brake selection a poor choice. I wasn’t looking for the cheapest. My goal is safety first.
 
Just hoping I can find a decent frame at a good price since I will be changing most of the hardware out.
If you poke around the internet, there are places that sell just frames, and used-bike sites, as well as whatever local sales / etc stuff you may have around you (thrift stores, craigslist, freecycle, etc).


Would a 26” cruiser fit my storage rack more easily, or should I consider starting with a MTB frame?
You will have to measure your rack vs the specific bike(s) you are looking at to know what will fit.


I was looking at cruisers for a smoother more stable ride. Is that incorrect thinking?
I would recommend trying out different regular bikes in the riding conditions you have to see what works best for you, then convert the one you find works for you.

Anything else is just guesswork.
 
Bargain basement disc brake bikes often come with cable operated disc brakes which I have found to be useless for actually stopping the bike.
Cable discs can be good. Cheap discs, cable and hydraulic, are not good.

Cheap linear pull brakes easily outperform most disc brakes of any price and actuation method, with even the slightest attempt at good setup. "Discs are better" is like "thick spokes are better": something that most technically ignorant people believe, but it's not true.

My e-cruiser has a $75 Avid BB7 with 180mm rotor on the rear wheel, because I'm using a rear rim that's too wide for rim brakes. In front it has a $20 Shimano V-brake. They both work strongly and reliably, with almost identical strength per lever effort. One of the brakes is noisier (scraping and singing sounds), requires much more frequent adjustment, and is much more difficult to adjust for anything other than pad clearance. Care to guess which?
 
I will do some more research. On crank vs hub drive. Maybe I jumped to the crank drive too early. This will be primarily for road/sidewalk use.
Crank drives are good for being able to shift the pedal drivetrain gears properly for varied terrain and riding conditions, to be able to use a lower power motor, smaller controller, and smaller battery to do a particular job more efficiently. They take more setup and more maintenance than hub drives.

If you don't have varied conditions or terrain, and always ride at essentially one slow speed on the sidewalks or roadside bike lanes, then a hub drive would be able to do the same job with the same small controller and small battery.

If you do have the varied conditions/terrain, and ride at a wide variety of speeds and need to accelerate quickly, a hubmotor will need to be more powerful, take a bigger controller and bigger battery to do the job vs a crank drive that you are shifting gears properly for.

You can experiment with various systems on the simulators at ebikes.ca with your specific conditions/etc to see how this works.



Bargain basement disc brake bikes often come with cable operated disc brakes which I have found to be useless for actually stopping the bike.
Cable operated brakes can work just fine, as long as they are good ones (like the single Avid BB7 I use with a 200mm rotor on the front of the heavy heavy-cargo trike SB Cruiser, which is enough stopping power to easily skid the wheel (you can't get more braking power than whatever it takes to skid the wheel).

Crappy ones like those that come on cheap bikes don't work very well, but that would be true even if they were hydraulic--it's not the activation method, it's the caliper design and manufacturing process. :(

Also, some cables are better than others--crappy cables can stretch more and sheaths have more friction and can also bind so not fully release the caliper, and crappy levers can flex more so not pull as hard. But poorly-bled or otherwise-problematic hydraulics can be mushy and respond much like crappy cables.

(but if a cable breaks roadside you can sometimes do a fix that will get you home; a hose breaking is probably not a roadside fix)

Another problem is often enough with crappy forks (especially cheap suspension ones) the lowers can twist during braking and misalign the pads to the rotors (both for rim and disc) and reduce braking or even cause it to not work at all.


Maybe I have an incorrect view of disc brakes. I thought that they would provide better stopping power, especially in damp/wet conditions. Is my brake selection a poor choice. I wasn’t looking for the cheapest. My goal is safety first.

It's not really disc vs rim, but good design/manufacture vs bad, not just of the calipers, levers, and activating interconnect, but of the frame/fork. ;)

What problems do you have in your normal rides?


I've used both with just as much success on my heavy cargo bikes and trike, as long as they're good enough brake quality--once the brake is strong enough to stop the wheel from spinning and skid the tire, that's as good as it gets.

Here in Phoenix, it's dry almost all the time, but when it gets wet it's usually either just enough to make the road slick with oil and flinty slimy dust-mud on the thin spattering of sprinkles so tires skid so easily that brakes of any kind are nearly useless, or it's inches deep and flowing down the streets as rivers, and washes the oil off rapidly, so braking is degraded but still possible.


Wet conditions can degrade both disc and rim brake performance, the rims will get wet first if it's just puddles, but if it's actually raining they'll both be wet and degrade performance--by how much depends on the rotor / rim surface, and the pads in use. Discs will get hot faster so they may boil away the water faster, but (especially hydraulics) because they get hot faster (smaller surface area, smaller thermal mass) they can also degrade performance if the caliper design or pad type performs less well as temperature increases.

Road contaminants (oil, etc) during the first part of the rain can splash on both rim and disc, but usually get on rims first. If you don't have this problem where you ride, then either type works just as well. If you do, then the disc will take longer / more splashing for the problem to happen, but with less rotor surface area to smear it on it can sometimes be a worse problem...but either way if the oil gets into the pads they can just plain stop working and you may have to replace them to fix it (you might be able to sand them down, though I've found this works better with the rubber rim pads than the metallic disc pads).

Pads make a huge difference too--there are many types and brands, and some work much better than others. Koolstop salmon work very well on rim brakes even when wet, though they can make quite a squealy racket under some conditions dependign on how well they're adjusted, and the particular rim surface. Semi-metallic pads on my Avid BB7 discs are normally quiet and grippy. I've used cheap garbage pads and they "work' but are not as good as the OEM ones and wear out really fast; my next experiment will be to try Koolstop pads for the BB7 when I run out of the others I've already got (which won't take long).
 
I really appreciate the input. I think I will follow the advice and keep an eye out for a used Electra Townie 9D as a base bike. Are the OEM brakes in the Electra adequate?
I’m still struggling with the power decision. I like the cost and simplicity of a rear hub drive system, but also like the idea of being able to use the gears in varied terrain as well as some of the torque sensing that is available on some mid-drive systems. Are there rear hub drive systems that allow for gear usage, and have torque sensing?
Why is a mid drive not recommended for newbies?
BTW, I have been working on/restoring vintage cars and motorcycles for over 40 years. I have been flying RC electric airplanes and helicopters for over 50 years. My point is not to brag, but to explain that I have quite a bit of mechanical and electronic knowledge. I also recognize that his knowledge does not make me an expert in Ebikes. Just wanted to point out that I do have some mechanical and electrical experience. I also have fabrication experience, however, that’s mostly useless since I now live in an RV and no longer have access to a full machine shop. I would think some of my experience would transfer over to Ebikes. Would you still recommend against a mid drive set up on my initial journey?
 
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Unless you have some unique requirements (e.g. have to climb a long steep hill during your daily commute, etc,), then I wouldn’t go with the mid drive. A geared or direct drive hub would be simple and low maintenance.
Where you RC experience comes in handy is that you probably already have the understanding about how to handle battery safety, balancing, etc., and the basic components used (battery, controller, motor). Most of these motors use hall sensors, while a lot of RC is sensorless, so possibly something to learn, but the background is useful. I like discs too, but hard to find on a steel frame, or cruiser frame, and most adapters are crap. I steel frame can be welded, so better if you want to fabricate a mount.
You can have torque sensing on a hub setup, if you choose the right controller/components. You should list all of your requirements to make component selection easier.
 
Unless you have some unique requirements (e.g. have to climb a long steep hill during your daily commute, etc,), then I wouldn’t go with the mid drive. A geared or direct drive hub would be simple and low maintenance.
Where you RC experience comes in handy is that you probably already have the understanding about how to handle battery safety, balancing, etc., and the basic components used (battery, controller, motor). Most of these motors use hall sensors, while a lot of RC is sensorless, so possibly something to learn, but the background is useful. I like discs too, but hard to find on a steel frame, or cruiser frame, and most adapters are crap. I steel frame can be welded, so better if you want to fabricate a mount.
You can have torque sensing on a hub setup, if you choose the right controller/components. You should list all of your requirements to make component selection easier.
Thank you for the thoughtful response.
I have definitely decided I’m going with the Elantra Townie
For a base bike. For the balance, I would like to be able to go up to around 30 mph top end. I wouldn’t see that often.
I really have no way of knowing what kind of terrain I will encounter, which is why I was hoping to have some type of gearing that works in conjunction with the motor. Maybe I don’t t understand, but it seems that the geared hub motors only use the gears while pedaling. Am I missing some education? My hope is to have as much as 50-70 mile range in a single charge. Is there a recommendation for a powered hub and controller combination that would allow for torque sensing?
 
I have definitely decided I’m going with the Elantra Townie
For a base bike.

Electra Townie is a awesome starting point, very comfy and relatively lightweight. I've converted a number of those. It's longer than a typical bike, if that makes a lot of difference to your packing and carrying options.

For the balance, I would like to be able to go up to around 30 mph top end. I wouldn’t see that often.

Here's something on which to ruminate about electric vehicles. Unlike farting motor vehicles, which operate well and efficiently (for them) at a very low fraction of their gross power or top speed, EVs have an efficiency sweet spot at about 3/4 of their unloaded speed (meaning full throttle, wheel off the ground). Lower speed than that and they can make more power and torque, but at lower efficiency, with more waste heat to get rid of. Higher speed results in good efficiency but rapidly diminishing power, so to run at those speeds you'll need a surplus of power and energy (which is more weight to carry, and more expense).

The moral of the story is your EV is best configured to go the speed you want to go, and not to have a dash speed that's much faster. It's common to hear a new convert say, "I won't be going over 20 mph most of the time, but I want to be able to go 40mph when I need to" or something along those lines. That's not how EVs work unless you cram them with way more heavy expensive power than what you'll be using regularly (looking at you, electric cars).

Unlike a farting vehicle, which makes maximum power up near the top of its RPM range, an EV makes maximum power at about half of its unloaded speed, and gross power drops from there to zero as RPMs rise. So to have a dash/sprint speed available, you either have to add power in a speed range where the motor is producing a diminishing amount of it, or you have to "gear" your system mechanically or electrically to place your power peak near your desired top speed, meaning you'll be running in the motor's low efficiency range almost all the time.

This is the best case to be made for through-the-bike-gears mid drive. Correctly used (and most people don't use them this way), you can have optimum power and efficiency at a whole bunch of different speeds, one per gear. But in my observation, most users just put them in top gear and leave them there.

My hope is to have as much as 50-70 mile range in a single charge.

This desire is very much at odds with 30 mph capability. You can do it, but your battery would be very big and heavy, and costly.

If you configure your bike to hit its efficiency sweet spot at 20mph or less (lower speeds yielding more range), then you can get the range you want. But it implies sitting on the bike for literally hours between recharges, which isn't how most folks tend to ride. When is the last time you sat on a bike for four hours at one session?

Is there a recommendation for a powered hub and controller combination that would allow for torque sensing?

I have no specific equipment to recommend, because every DIY torque sensor I have seen so far has been fiddly, fragile, expensive, and generally a pain in the butt. But there are controllers that include native support for torque sensors. Motors (except those that have a built-in controller) don't know or care whether there's a torque sensor.

You can retrofit a torque sensor to any motor and controller if you use a Grin Cycle Analyst (very good and versatile, very not cheap or easy to set up).

As a final note, I'll point out that my preferences in e-bike systems have evolved from very simple (because that was all I could get my head around at first) to feature-packed and mechanically complex, back to very simple. All my bikes now are throttle-only, with hub motors. At this point I often don't even bother to add a display or control panel. It still does everything I really want to do, with a minimum of elements to have problems, and less stuff to troubleshoot.
 
I’m still struggling with the power decision. I like the cost and simplicity of a rear hub drive system, but also like the idea of being able to use the gears in varied terrain as well as some of the torque sensing that is available on some mid-drive systems. Are there rear hub drive systems that allow for gear usage, and have torque sensing?
Torque sensing isn't (normally) part of the motor, except for middrive systems (where if it's not part of the motor, you don't usually get to add it because the systems are integrated all-in-one-unit).

There are a number of different types of torque sensors to tell how hard you're pedalling...some replace the BB where your pedals bolt on, some replace part of the pedal-side dropout for the chain drive (requires frame modification or a specific frame made for the specific sensor), and nowadays there are a very few hubmotors (like Grin All Axle) that have or soon will have options for built-in TS. Each sensor detects pedalling forces differnetly, so some are suited for certain types of applications better than others.

So, you can build a hub drive system without TS, and add it later if you decide you need/want it, as long as either your controller supports it already, or you replace the controller with one that does, or use the Cycle Analyst v3 to interpret the TS output and make a throttle signal to run the controller from.

The CA isn't plug and play, and requires understanding what it does (reading and following the documentation) to set it up correctly (or a lot of experimentation), then fine-tuning as you ride for a bit. It also works easiest with a "dumb" controller that doesn't use a display or have any input options other than a throttle, or any setup menus, apps, programs, etc., so you don't have to deal with controller options interacting with the CA options.


(the more options a system or part has, the more you will have to setup to get it to work, and the more interactions between parts that you have to resolve to get it to do what you want).


Why is a mid drive not recommended for newbies?
Mostly it's a lot of maintenance, and it requires specific setup for each bike for gearing, chainline, and sometimes requires modification of your BB and/or frame to make it fit. You have other experience that, if you are willing to research the various issues as they come up, will probably make it easy to deal with them.
 
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Torque sensing isn't (normally) part of the motor, except for middrive systems (where if it's not part of the motor, you don't usually get to add it because the systems are integrated all-in-one-unit).

There are a number of different types of torque sensors to tell how hard you're pedalling...some replace the BB where your pedals bolt on, some replace part of the pedal-side dropout for the chain drive (requires frame modification or a specific frame made for the specific sensor), and nowadays there are a very few hubmotors (like Grin All Axle) that have or soon will have options for built-in TS. Each sensor detects pedalling forces differnetly, so some are suited for certain types of applications better than others.

So, you can build a hub drive system without TS, and add it later if you decide you need/want it, as long as either your controller supports it already, or you replace the controller with one that does, or use the Cycle Analyst v3 to interpret the TS output and make a throttle signal to run the controller from.

The CA isn't plug and play, and requires understanding what it does (reading and following the documentation) to set it up correctly (or a lot of experimentation), then fine-tuning as you ride for a bit. It also works easiest with a "dumb" controller that doesn't use a display or have any input options other than a throttle, or any setup menus, apps, programs, etc., so you don't have to deal with controller options interacting with the CA options.


(the more options a system or part has, the more you will have to setup to get it to work, and the more interactions between parts that you have to resolve to get it to do what you want).



Mostly it's a lot of maintenance, and it requires specific setup for each bike for gearing, chainline, and sometimes requires modification of your BB and/or frame to make it fit. You have other experience that, if you are willing to research the various issues as they come up, will probably make it easy to deal with them.
Thank you so much for all of that info. I think that I will be purchasing the Electra Townie 9D with a Bafang rear hub drive. I appreciate all of the input.
 
The whole point is to maintain the cruiser look and style? if you already had a single coaster brake bike like that, another way is to replace the front fork with one that will take a disk brake, Then find a used front wheel. Keep the coaster brake. Install a TSDZ2B middrive ($290) with coaster brake option, using a BB adapter if it's a one piece crank. Install the (free) OSF firmware and run it in cadence mode. Plenty of power to move along at cruiser speeds. You only need a small bottle battery (250WH), which will look appropriate, to go 18-20 miles. Not for a newbie, I guess, and not economical. Just another debacle for a hobbyist.

I bought a $45 bafang front motor a few years ago (so did Chalo) and not having a bike for it, I bought a cheap Kent 7 speed cruiser. Alloy frame. Rim brakes. I used it with an equally cheap $45 used e-scooter battery, which I wrapped up in a big bag strapped to the top tube. Low cost ebiking,
IMG_1688.JPEG 1_image.JPG
Eventually, I put some money into looks. Different battery. Hydraulic disks. I never wanted a cruiser though.
 
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I bought a $45 bafang front motor a few years ago (so did Chalo) and not having a bike for it, I bought a cheap Kent 7 speed cruiser. Alloy frame. Rim brakes. I used it with an equally cheap $45 used e-scooter battery, which I wrapped up in a big bag strapped to the top tube. Low cost ebiking,

I thought of that initially when addressing the OP's question, but I think that approach loses its appeal if you want to go faster than about 25 mph on a bike that places most of its weight on the non-motorized wheel.

For the OP's application, I think that would be an almost perfect solution (and cheap, as you point out). But for the OP's stated specification, I think it might result in a bothersome amount of skidding.
 
Thank you so much for all of that info. I think that I will be purchasing the Electra Townie 9D with a Bafang rear hub drive. I appreciate all of the input.
The new Townies have a Hyena motor and, more importantly, 250 wh battery. The battery seems good for a trip to the market, but not long range. Also, top speed is 20 mph AFAICT.
 
I think the Electra Townie Go! line of ebikes is out of his price range. I rarely see them sell secondhand either, unlike the acoustic versions where there are a dozen for sale after every Burning Man festival. He's just looking for a cheap cruiser with disc brakes to put a kit on.
 
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