Feedback on conversion plans

Credible Hulk

Active Member
A while ago I acquired an old cruiser bike which I cleaned and fixed up. It looks beautiful but it has a heavy steel frame, forks, rack, fenders etc. and it's a beast to ride (or walk) on hills. So, I thought I might convert it to an e-bike using a hub motor kit instead.

I do have prior experience with ebikes (an e-fatbike with pedelec and throttle, and an e-scooter with twist throttle only) but have never done a conversion. That's why I'd like some input from people who have experience converting older bicycles to e-bikes.

I'd like to preserve the look of the bike as much as possible while still creating a fun and safe e-bike. Here's what the bike looks like:

Supercycle Newport.jpg


So far besides cleaning it up and lubricating it, the only change I've made is to switch to cream coloured smooth tread city tires. This bike will be ridden primarily on city streets and paved bike trails. I live in an area with some hills, including a few steep ones.

My first concern is brakes. This bike doesn't support disc brakes, because there are no eyelets on the forks to support the activator and the wheels don't support the discs. I plan to get a hub motor/wheel and I could put a disc on that wheel, but again - no eyelets on the forks. Could the activator be installed using hose clips and some kind of adapter?

I've read that the old style caliper brakes can work on an ebike with the right pads if they're in good shape, the cables are good, and they're properly adjusted. My wheel rims are alloy and pretty heavy and sturdy, and the brake calipers are also heavy and solid. Another option might be a disc brake on the wheel with the motor, and caliper on the other wheel. I'm thinking this might work better if the motor/disk brake were on the front wheel. For brake pads (caliper) I read that Kool Stop Dual-Compound brake pads are good for higher speed.

Second concern is the best wheel for the motor. I'm not interested in a mid drive (looks horrible on this style of bike and I'm afraid to try installing one). Right now I'm leaning heavily towards putting it on the front wheel.
Reasons:
- bike has a long, heavy steel rack on the back
- I plan to install the battery on the rack because there isn't much space for it on the frame
- since it's a cruiser the rider sits upright rather than leaning forward

So I thought it might be better to put the motor on the front wheel to balance the weight of the bike. It will also be easier to install, however I'm willing to install it on the back wheel if that would be better. On the front wheel I would use two torque arms. I'm not sure if any would be needed on the back wheel (with the motor on the front). Both of the ebikes I've had so far had rear wheel motors, so I'm wondering about the learning curve to drive a front wheel motor ebike.

For the motor I've decided on this one, it's available for front or rear hubs. It's called a Magic Pie Vector. The motor is brushless gearless. Specs:

Built in fan
Improved heat dissipating
Easy Disk Brake mounting
Major improvement in quality of wiring harness and plugs

Motor:

24v- 60v
250W – 1500W
Brushless Gearless Hub Motor
High Efficiency / High Torque
Super Slim for common bikes

Controller:

Vector Controller with Sine Wave Technology and Bluetooth!
24v/36v/48v Multi voltage
Max 25a Continuous power
Upgraded Mosfet
Regenerative Braking
Easily replaceable by plug
PC programmable
Forward/Reverse

For the battery I'm thinking of a 48V 13.6AH Panasonic Shark Pack because of the weight of the bike and the hills in my area. I also tend to travel fairly long distances (like running multiple errands) so I need a bit of range.

Pedelec?
I prefer throttle only, but in my city all ebikes using bike infrastructure must be pedelecs. To replace the bottom bracket to install a sensor, is a torque wrench needed? I don't have one and they're expensive, so I'd need to budget for it.

Also, has anyone ever used one of these sensors?
https://www.goldenmotor.bike/product/pedelec-2/

It's simple but compatible with the motor I want. I can get a "smart screen" which works with this motor's controller and allows me to control the level of this pedelec.

That's all I can think of for now. Sorry about the novel but I thought it would make more sense to include my questions in a single thread.
 

J.R.

Well-Known Member
Brakes, as stated being your first concern. You can get away with rim brakes if you keep the power/speed modest. I would stay below 20 mph. That's my opinion. Road bikes often use rim brakes, but you'll be stopping more weight and probably won't have the high quality components.

You could upgrade the rim brake components to be sure you get the best performance. You might get away with just high quality cables and pads. High quality cables function smoother and stretch less. For pads Kool Stop offers a high performance ebike rated rim pad.

https://www.koolstop.eu/catalog/rim-brakes-pads/e-bikes/e-bike-compound/

As important as components is making sure to regularly clean the rims. Aluminum rims oxidize fairly quick, which affects brake performance.

Another option are hydraulic rim brakes. They are expensive and might look odd on a classic cruiser.

Good luck, have fun! Keep us updated with pics. Looks like a fun project.
 

indianajo

Well-Known Member
With all that weight I would go with mechanical disk brakes. I find disk brakes MUCH better in the wet than rims. Hose clamps won't be strong enough to mount the calipers to the struts. I would bend U out of 1/8" steel strap, but this does require a vise, a bench, and a hammer. Use safety glasses when drilling holes. Strap aluminum from hardwares doesn't bend, it contains silicon and fractures.
I find the drag of a DD hub motor annoying but necessary since geared hub motors aren't available anymore. I ride power free quite a bit, to keep my heart in shape. The one US vendor that had one, he thought 330 lb gross put me in the catagory of pedicabs and wouldn't sell me a geared hub motor unless I bought a 36 v battery from him. I think regenerative braking is a feature that will force you to use electricity all the time. With 17.5 AH only getting me 20 miles at 40 deg F, pedaling without electricity is important to my range.
I put a pedal sensor on a nineties Huffy savannah with a one piece crank. The standard sensor plate wouldn't fit as was, and I had to grind the center hole out big enough to clear the bend in the crank. then I had to glue in wood wedges to close the hole again to fit the crank. I used 3m weatherstip adhesive as the glue. Use safety glasses if grinding out the hole with a burr. Don't try drilling a hole that big, you'll break the plastic.
I also had to mount the magnetic pickup for the pedal sensor on a arm hung from the kickstand flange. a bit of plastic angle sawed from a lawnmower hood made a nice strut.
As far as pedalassist, I think it is postively dangerous the way the cheap ones accelerate to PAS1 at 30 amps. If there was ice on the road this could cause the front to go down. It also is likely to drive me into chugholes in the berms I ride on in this state. I think you should move to a state that doesn't want to cripple its citizens so they get back in their cars and pay more taxes. A throttle for gradual acceleration is an important safety feature IMHO.
 

Credible Hulk

Active Member
Brakes, as stated being your first concern. You can get away with rim brakes if you keep the power/speed modest. I would stay below 20 mph. That's my opinion. Road bikes often use rim brakes, but you'll be stopping more weight and probably won't have the high quality components.

You could upgrade the rim brake components to be sure you get the best performance. You might get away with just high quality cables and pads. High quality cables function smoother and stretch less. For pads Kool Stop offers a high performance ebike rated rim pad.

https://www.koolstop.eu/catalog/rim-brakes-pads/e-bikes/e-bike-compound/

As important as components is making sure to regularly clean the rims. Aluminum rims oxidize fairly quick, which affects brake performance.

Another option are hydraulic rim brakes. They are expensive and might look odd on a classic cruiser.

Good luck, have fun! Keep us updated with pics. Looks like a fun project.

Re the brakes, so far I haven't been able to find non-disk hydraulics. I did read an article a while ago that said caliper/rim brakes can be OK to use on an ebike as long as the rims are kept clean and in good condition, and as long as you use high quality pads. I didn't know Kool Stop made ebike pads, but it's a moot point since apparently they're not available in North America as far as I can find. Amazon carries their entire line - except for the ebike ones of course. I can get dual or triple compound pads which were recommended in the article. Another option might be to replace the brakes with higher end, more powerful caliper brakes meant for long trips, like these Shimanos.

Speed - I live in an area that limits top speed of ebikes to 20 mph anyway. I wasn't planning on going much faster. I'm used to that speed from riding my previous vehicles. Cops can be overzealous when it comes to e-bikes. I plan to set the max speed in my controller to maybe 25 tops.

If worse comes to worst and I can't find the brakes I need, I have a plan B - I already picked out a new ebike that would be ready to go. I can always use the old bike to putter around the neighbourhood on short trips.
 

harryS

Well-Known Member
For under 20 mph, I think caliper brakes should work well. If your old ones have lost their spring tension, etc, you may want to get new ones and also replace the cable/sheath. On my first conversion, I lost most of my of pull force from friction of the old rusty cable inside its sheath.

As I type this, I see indianjo describe how he got his PAS sensor to fit onto a one piece crank. I think you will have the same issue.

I'm not sure that kit you describe supports PAS, and if it does, it may not work like you want. Better query the vendor for how their PAS works. When Luna sold a kit similar to this, the documentation said PAS was like activating cruise control. When you turned it on, the controller used the rotation of the pedals instead of holding the throttle to maintain a preset speed. I was hoping to buy the Luna kit until I read that.

Edit: I see that if you use the Golden Motor part and run bluetooth, the PAS works better? Good luck on that. Unlike younger folks that seem to have a phone charged 24/7, mine is running lucky to be running 7/24.
 
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JRA

Well-Known Member
Re the brakes, so far I haven't been able to find non-disk hydraulics. I did read an article a while ago that said caliper/rim brakes can be OK to use on an ebike as long as the rims are kept clean and in good condition, and as long as you use high quality pads. I didn't know Kool Stop made ebike pads, but it's a moot point since apparently they're not available in North America as far as I can find. Amazon carries their entire line - except for the ebike ones of course. I can get dual or triple compound pads which were recommended in the article. Another option might be to replace the brakes with higher end, more powerful caliper brakes meant for long trips, like these Shimanos.

Speed - I live in an area that limits top speed of ebikes to 20 mph anyway. I wasn't planning on going much faster. I'm used to that speed from riding my previous vehicles. Cops can be overzealous when it comes to e-bikes. I plan to set the max speed in my controller to maybe 25 tops.

If worse comes to worst and I can't find the brakes I need, I have a plan B - I already picked out a new ebike that would be ready to go. I can always use the old bike to putter around the neighbourhood on short trips.

Go with Plan B.
 

harryS

Well-Known Member
Smaller motor in the rear. Saddlebags holding the battery and electronics. No display, Just a throttle and pedal assist. It will look like a classic cruiser, won't go too much faster and be within capabilities of brakes. A show bike.

You should read what Eric Hicks, owner of Lunacyle.com, once said about the cosmetics of the golden pie motors. I guess they run fast though,
 

Thomas Jaszewski

Well-Known Member

Credible Hulk

Active Member
Thanks for all the replies so far!

Re PAS - The Golden Motor disc sensor will work with the Magic Pie motor and GM's proprietary "Smart Screen" or Bluetooth to regulate the assist level. However, it only has 6 levels I think. I don't think it's worth the effort of gluing wood, enlarging the hole in the sensor plate etc. to install PAS. I want PAS because the whole point of switching from scooter to bicycle style ebike is so that I can use bike infrastructure like mixed use paths, instead of being stuck on the road all the time. Non pedelec ebikes aren't allowed to use bike infrastructure here. By the way I wasn't planning on using the Bluetooth because my phone is a piece of junk and would either drop the connection or crash the controller app.

Brakes - It seems from a couple of replies that rim brakes on this bike could be dicey and not 100% trustworthy. I know from experience with my scooter which is speed limited to 20 mph that exceeding that speed happens all the time, like if you have a tail wind or are going downhill. I live in an area with a lot of hills. I could be going down one of these hills doing 25-30 and have to stop at a light at the bottom of a hill, or stop when the road and my rims are wet. I don't want to be constantly worrying about brake failure while riding. With my luck I'd run straight into the back of a police cruiser. I checked hydraulic rim brakes and the prices are far out of my budget, plus I read that they can crush aluminum/alloy rims.

I think in this case that I'll just buy a new ebike. In the future I may get another secondhand bike to convert, but this time it will be a newer bike that already has disc brakes.
 

Credible Hulk

Active Member
The right bike is the one that fits you best. Pick a bike you’d be comfortable pedaling.


Yes, a comfortable bike is good, however there are technical criteria to consider such as whether it will support disk brakes or pedelec sensors.

In the "guide suggestions" thread I suggested they do a thread about how to choose a bike to upgrade to an ebike. That way a first timer like me won't go out and buy a secondhand bike and then find out it isn't suitable as an ebike because they didn't know what to look for. However, when I bought the beach cruiser I was just planning to use it as a standard bike, but when I found out it's poor on hills I thought of upgrading it.
 

harryS

Well-Known Member
C. Hulk, I still think that is still a great bike to electrify, but going at it with a 30 mph capable hubmotor is what brought out the red flags.

Rim brakes are fine for recreational riding. I have converted two 20" folders and two mountain bikes 26" and 700cc, where I kept the rim brakes. At 13-15 mph, we only ride a little faster than most of the recreational riders. I know the brakes will work though for higher speeds. We've taken the mountain bikes to mountain country and come down hills at 25 mph, but that's far different from riding in traffic at 25 mph, where you might have to stop on a dime. Also different from commuting thru slush and mud. where disks are superior.

Best bike for a newbie to convert is a steel frame bike. It's more forgiving of install errors. You can bend it a bit w/o worry if a hub motor is too narrow or too wide. You can drill it if needed, and that's generally safe. Safer for front motors.
 

Thomas Jaszewski

Well-Known Member
I'd put a stealthy front hub on. Something like the little Bafang G310. Pedelec is an easy install and rim brakes will be just fine at lower speeds. If you want the fastest bike an upright cruiser may not be the right choice.
 

Credible Hulk

Active Member
C. Hulk, I still think that is still a great bike to electrify, but going at it with a 30 mph capable hubmotor is what brought out the red flags.

The hubmotor I chose is 500w, capable of variable speeds depending on which throttle and battery you choose. Its max is 48V. I was going to select that based on the extra weight on the bike and the fact that I live in a hilly urban area. My plan was to program the max speed at 20 mph which is the legal limit where I am. If I wanted I could dial it back to 36v instead.

Rim brakes are fine for recreational riding. I have converted two 20" folders and two mountain bikes 26" and 700cc, where I kept the rim brakes. At 13-15 mph, we only ride a little faster than most of the recreational riders. I know the brakes will work though for higher speeds. We've taken the mountain bikes to mountain country and come down hills at 25 mph, but that's far different from riding in traffic at 25 mph, where you might have to stop on a dime. Also different from commuting thru slush and mud. where disks are superior.

I live in an overcrowded city and I ride for a variety of reasons, sometimes it's errands or just to get from A to B through traffic, with its many bad and reckless drivers. On every trip I have to panic brake at least once due to morons who don't look where they're going before exiting driveways, turning or changing lanes. There are several large hills which I have to navigate no matter where I'm going.

I've spent days researching ebike brakes, and every source has a different conclusion. Some say that using the rim brakes would be safe but only if I use special Kool Stop pads. The vast majority state that with a heavy steel ebike (beach cruiser not designed for hills, has to be walked up even small hills) doing more than 20 mph, rim brakes do not provide a safe margin of error in an emergency - particularly if the road is wet, sandy or dusty. My bike is almost 20 years old, and so are its rims. Sure, you can stop fine while cruising down a smooth, dry road doing less than 20 mph, but what about while going down a steep hill full of sand and potholes at the side of the road, doing 30 mph and a car pulls out of a driveway in front of you? Or what about getting caught in a sudden rain shower when there's a thin film of grease on the road from the cars? I've had people tell me "just be careful about your speed and make sure you do less than 20 mph and you'll be fine". But why should I be obligated to crawl along like a tortoise below my max legal speed in case I won't be able to stop? I'd rather have a margin of safety and not have to obsess about my brakes or my speed every time I ride.

I've also read that V brakes might be an option, but again there are conflicting articles about whether or not they grip more strongly than regular cantilever brakes.

Best bike for a newbie to convert is a steel frame bike. It's more forgiving of install errors. You can bend it a bit w/o worry if a hub motor is too narrow or too wide. You can drill it if needed, and that's generally safe. Safer for front motors.

I agree with that, and that's why I thought this steel framed beach cruiser would make a good ebike. I thought a front motor would be best to balance the weight and battery on the back of the bike, but I wonder if the rear motor would be a better option for traction and handling. I think in the future I would choose a newer bike that has disc brakes, at least I'd have the flexibility to choose those or hydraulics.
 

Credible Hulk

Active Member
I'd put a stealthy front hub on. Something like the little Bafang G310. Pedelec is an easy install and rim brakes will be just fine at lower speeds. If you want the fastest bike an upright cruiser may not be the right choice.

I could get a smaller Smart Pie front hub motor from Golden Motor, but it doesn't have some of the features of the bigger one. For example it has an external controller instead of an integrated one that can be programmed with a USB cable. I actually like the appearance of the Pie motors, even the big ones.

Re the Pedelec, I don't know much about installing them. I've seen ones that go through the bottom bracket, and others that appear to attach either to the pedal arm or the hub motor. I have no idea how to figure out the right size to match my bike for the ones that go through the bracket. I measured my bottom bracket by width and diameter in mm but the numbers bear no relation to the sizes of pedelec sensors. I can get disk style sensors but I'm not sure where they can be installed.

I do like a bit of speed sometimes. When I was riding my e-scooter I used to get impatient being stuck on 20 mph or less. Eventually I took the speed limiter off of it. If I'm riding a distance on a flat open road with little traffic, I like to go a bit faster - which doesn't help the braking situation. That's another reason I'm not too keen on electrifying the cruiser bike. It's a pretty bike and I can still use it for puttering around the neighbourhood with no motor. I can always find another suitable upgrade bike at the local police auction or want ads.
 

indianajo

Well-Known Member
I ran into the side of a car that ran a stop sign with rim brakes 2 years ago. It was raining, I'd stopped already at the stop sign, you'd think rim brakes could stop me at 3 mph. Wrong! I was wearing flourescent green, she must have been blind as a bat! Or stoned.
Having grown up on a coaster brake, I've viewed rim brakes as a poor substitute every since I bought the English "racer" 3 speed. Now you can buy disk brakes, which are much better in the wet. My mechanical tekkos have needed one adjustment in the 13 months I've owned them. They do not deteriorate in the rain nearly as badly as rim brakes, however "premium" they are. Disk brakes are 12" above the puddles. If I was buying new I'd buy shimano mechanical disks, because you can actually buy the pads for them.
I think the pedal assist sensor I bought from ebikeling.com was designed for 3 piece mountain bike cranks. Cranks don't have a name, whatever they are selling right now is what everybody carries. Try cruising the bike parts stores like competitivecycle or moderncycle for sprockets - no descriptions! I've got 4 different types of cranks in my bike fleet that goes back to 1966.
 
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Credible Hulk

Active Member
I ran into the side of a car that ran a stop sign with rim brakes 2 years ago. It was raining, I'd stopped already at the stop sign, you'd think rim brakes could stop me at 3 mph. Wrong! I was wearing flourescent green, she must have been blind as a bat! Or stoned.
Having grown up on a coaster brake, I've viewed rim brakes as a poor substitute every since I bought the English "racer" 3 speed. Now you can buy disk brakes, which are much better in the wet. My mechanical tekkos have needed one adjustment in the 13 months I've owned them. They do not deteriorate in the rain nearly as badly as rim brakes, however "premium" they are. Disk brakes are 12" above the puddles. If I was buying new I'd buy shimano mechanical disks, because you can actually buy the pads for them.
I think the pedal assist sensor I bought from ebikeling.com was designed for 3 piece mountain bike cranks. Cranks don't have a name, whatever they are selling right now is what everybody carries. Try cruising the bike parts stores like competitivecycle or moderncycle for sprockets - no descriptions! I've got 4 different types of cranks in my bike fleet that goes back to 1966.

Yup. When you've been through a few accidents caused or made worse by rim brakes not gripping, you get a little nervous at the thought of using them on a heavy, motorized bike. I used to do road races and long distance tours and was involved in several accidents caused by rim brake malfunctions - including another cyclist running into ME because his brakes failed. Drivers these days either don't look, or believe themselves to be the only ones with the right to use the road. Either way, they don't look where they're going and expect everyone else to get out of their way or stop on a dime.

When I was a kid in the seventies our bikes all had coaster brakes. The good news is they're making a comeback for certain kinds of bikes including beach cruisers. If you had coasters on an ebike you could set the controller to cut the motor as soon as the bike is pedalled backwards, and you could stop more reliably than with rim brakes.