Looking to build a bike

Hi guys, this is my first time here. I browse some of the forum and have decided that I am definitely interested in building a bike. I plan on using it as a daily driver and leaving my car in my driveway most of the time.

Purpose: Daily Commute so I can ditch my car commute and save money
Distance: 3 Miles each way, can't charge at work because it's against policy
Desired trip time: 5-8 minutes
Desired Cruising Speed: 35-45 MPH but will likely go slower for safety reasons
How hard I want to pedal: Not much, only when I want to exercise
Weight: 165-170 lbs 6'
Location: Sacramento
Terrain: Some offroad bike trail, sometimes a little mud and dirt, mostly flat road, biggest incline is about 50 feet.
Budget: As close to 1500-2500 as I can get
Motor Type: Rear Hub Motor or Mid Drive

I plan on either using the vector bike frame or the futr bike frame. If I don't use one of those I might even go with a custom bike frame built by the shop across from where I work. He mostly does motorcycles but I talked to him and he said he would do a bike for me if I want. Not sure how much that would cost though so it might be something I do in the future when I've saved a bit more.

I plan on building the battery pack myself. I will probably go with a 52v 20ah build to start. I'm not too sure of anything else. I looked for gear boxes and can't seem to find any for sale I'm not sure if I even need them. I'm really not sure if I should go with a mid drive or a rear hub motor but I'm sure you guys will give me plenty of opinions. Let me know what you think and thank you for any advice.

I have been ride my e-bike for about a year now. I love using it. It gets me on my bike more often. I like not buying as much gas. I like the exercise i get . I like the hub motor because as i age and with deep snow and ice in the winter i would like to build a tadpole trike and just switch the rear wheel and other components for the season change . I decided not to build a battery because of the little difference in cost when just building one battery and for safety reasons. My job as changed since I started my build so my commute as change from 8 blocks to 5 miles. I love having extra battery Amp hours. I had problems with a used Bionx system and have been happy with the performance of Grin products. hope this helps

jerkface38 said:

Desired Cruising Speed: 35-45 MPH but will likely go slower for safety reasons
How hard I want to pedal: Not much, only when I want to exercise
Weight: 165-170 lbs 6'

I plan on either using the vector bike frame or the futr bike frame. If I don't use one of those I might even go with a custom bike frame built by the shop across from where I work.

I will probably go with a 52v 20ah build to start.

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Your choice of frames will limit the choices of motors, due to the drop out widths, so you'll need to decide on one or the other. Those frames will fit big motors, with big power demands.

Ignoring the drop out criteria for a moment, I don't think your battery will get you there; you'll likely need to go to a 72 volt battery, even with a less power thirsty motor. You can play with the Grin motor simulator, and set the controller to something high so it won't be the bottleneck, and the battery to your desired voltage and capacity, then test various motors. You want fast wind motors, and since Sacramento is dead flat, you don't need to adjust grades in the simulator.

Here's an A/B comparison of the fast turn Leaf motor at 52 and 72 volts, approximating your total weight at 220, no grade. You can select different motors to see what you get, but pay attention to the bottom section that tells you whether the motor will melt and after how long.

https://www.ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_52_0.2_20&cont=cust_60_120_0.03_V&hp=0&axis=mph&mass=100&cont_b=cust_60_120_0.03_V&motor_b=Leaf%205T&batt_b=cust_72_0.2_20&hp_b=0&bopen=true

Welcome to the forum, by the way. :thumb:

I agree with the 72v battery if you want 40+mph. Your link was for the 5 turn Leaf motor (Grin's default), and here is a link with the 4 turn (Leaf's default config) rpm/v numbers pasted in:
https://www.ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_52_0.2_20&cont=cust_60_120_0.03_V&hp=0&axis=mph&mass=100&cont_b=cust_60_120_0.03_V&motor_b=Leaf%205T&batt_b=cust_72_0.2_20&hp_b=0&bopen=true&kv=13.16&kv_b=13.16

Helps a little bit for speed. The Vector and Futr bike frames are pretty serious for a 3 mile commute Don't they use a 20" rear wheel? In that case, the fast wind motor and higher voltage battery will matter even more. I personally view direct drive hub motors as the most reliable, but admit I haven't tried a mid-drive, like the Cyclone 3 kilowatt.

For a commute that short I'd look for a high drain pouch cells and run high volts.

I personally like mid-drives and the Lightning Rods big block is a nice option to get the performance you're after.

thundercamel said:

I personally view direct drive hub motors as the most reliable, but admit I haven't tried a mid-drive, like the Cyclone 3 kilowatt.

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On flat terrain combined with not wanting to pedal, direct drive is probably the way to go. You can ride all day and never have to shift (or pedal to shift).

Grantmac said:

For a commute that short I'd look for a high drain pouch cells and run high volts.

I personally like mid-drives and the Lightning Rods big block is a nice option to get the performance you're after.

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The commute is short but I also intend to use it to see family and friends who are 10+ miles out. I'm basically going to be using it for everything including grocery shopping within a short distance.

jerkface38 said:

I'm basically going to be using it for everything including grocery shopping within a short distance.

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Are you adding a rack?

thundercamel said:

I agree with the 72v battery if you want 40+mph. Your link was for the 5 turn Leaf motor (Grin's default), and here is a link with the 4 turn (Leaf's default config) rpm/v numbers pasted in:
https://www.ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_52_0.2_20&cont=cust_60_120_0.03_V&hp=0&axis=mph&mass=100&cont_b=cust_60_120_0.03_V&motor_b=Leaf%205T&batt_b=cust_72_0.2_20&hp_b=0&bopen=true&kv=13.16&kv_b=13.16

Helps a little bit for speed. The Vector and Futr bike frames are pretty serious for a 3 mile commute Don't they use a 20" rear wheel? In that case, the fast wind motor and higher voltage battery will matter even more. I personally view direct drive hub motors as the most reliable, but admit I haven't tried a mid-drive, like the Cyclone 3 kilowatt.

Click to expand...

The commute is 3 miles but I plan on riding it everywhere. Even with my three mile commute I'm still spending $80-$120 a month in gas for my Corolla. I'm open to opinions on bike frames as well, only picked those because they seem a lot sturdier than the rest and I want it to last a long time since I'm basically getting it for $275 off through my credit card bonuses after I hit $1,000. I believe the site said that it can go up to a 26" or 27.5" wheel (would need to look again).

I'm going to look into the leaf Motors. I really don't know a whole lot about this stuff but I feel I've learned quite a bit in just this last week. I feel that by the time the malectrics spot welder gets here I'll have confidence in building a 52v battery. I'm still not sure how long before I'll feel safe building a 72v battery. You guys have been a big help already so thanks for that.

I'll be looking into high drain pouch cells but I also want something that has a moderate duration of charge. Also need to figure out the regenerative braking system. Also I'm wondering if direct drive is the same thing as mid-drive or if they're different things? Edit: just looked into it. They are definitely different things. I'm used to just calling them front and rear hub motors :lol:

E-HP said:

jerkface38 said:

I'm basically going to be using it for everything including grocery shopping within a short distance.

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Are you adding a rack?

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Probably not, just going to use my backpack. Might look into adding a rack in the future but it's likely not going to be necessary.

3 miles at 20 MPH average will take you 9 minutes. 3 miles at 40 MPH will take you 4 1/2 minutes. Stop signs and lights could add a few minutes to that. You don't need a 45 MPH bike for a 3 mile commute. A 20 MPH bike can easily be built for under $2000. A safe 45 MPH bike, not so much. To build the 20-25 MPH bike, just buy a used mountain bike on Craigslist and buy a motor kit and battery from EM3EV or buy a cheap DD kit on eBay and buy the battery from a reputable source.

The commute is 3 miles but I plan on riding it everywhere. Even with my three mile commute I'm still spending $80-$120 a month in gas for my Corolla.

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Although your proposed build sounds like fun, one doesn't build a custom 40 - 45 mph ebike to save money.
Maybe if you were to build a more commute appropriate 20 to 25 mph assist ebike w/ a simple hub motor and a 48 Volt pack, you could see a savings after a while.
Really, if economy were your true goal, you could buy a new Chinese scooter or sm. motorcycle for less $$ that a 45 mph ebike will end up costing over time. At 30 miles a week @ 75 mpg,....well, you get the math. And no constant fussing and fiddling that an ebike requires.

motomech said:

\
Although your proposed build sounds like fun, one doesn't build a custom 40 - 45 mph ebike to save money.

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Bingo. If saving $1000 a year on gas is a big deal you are barking up the wrong tree with an ebike that goes 45+ for any distance with any reliability.

As a general rule, you don't build an ebike to save money. You might end up saving money in the long haul, but if you don't totally ditch the car and insurance, you won't save much. If you really want a car replacement bike, I think you need a long or medium tail that will allow you some space to build some cargo carrying capacity. Look up longtail on this forum for ideas. Use a rear DVD motor and understand that this bike won't like trail riding much. You could easily build it for 35 MPhil or so without getting to exotic but for general purpose riding, 25 MPhil is often plenty and will extend your range a lot,

$100 a month on Gas suggest about 750 miles a month driven. You can do that with an ebike, but you'll really want a comfortable and versatile bike.

Consider a long or mid tail cargo bike if you really want to replace a car.

jerkface38 said:

I feel that by the time the malectrics spot welder gets here I'll have confidence in building a 52v battery. I'm still not sure how long before I'll feel safe building a 72v battery.

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I don't think there's any inherent differences when it comes to safety between building a 53v or 72v pack. Basically you're just placing the nickel strips in a different configuration so the series strings have more cells. In other words, you can make the same mistakes with a 52v pack as with 72v, and end up with the same big ball of fire.

Why do you want a 45 mph cruising speed to ride... 3 miles ?
30 mph will be enough, your bike will be lighter, your battery also, and your ride will be only 2 minutes longer

Jil said:

Why do you want a 45 mph cruising speed to ride... 3 miles ?
30 mph will be enough, your bike will be lighter, your battery also, and your ride will be only 2 minutes longer

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I said previously: The commute is short but I also intend to use it to see family and friends who are 10+ miles out. I'm basically going to be using it for everything including grocery shopping within a short distance.

Its kind of like having an extra oomf just in case or having more space in your house that you dont need but could use if you do. It's the same principle just applied to a vehicle. I just want the option.

E-HP said:

jerkface38 said:

I feel that by the time the malectrics spot welder gets here I'll have confidence in building a 52v battery. I'm still not sure how long before I'll feel safe building a 72v battery.

Click to expand...

I don't think there's any inherent differences when it comes to safety between building a 53v or 72v pack. Basically you're just placing the nickel strips in a different configuration so the series strings have more cells. In other words, you can make the same mistakes with a 52v pack as with 72v, and end up with the same big ball of fire.

Click to expand...

There really isn't but the difference is I already know how to do 52v and I don't know how to do a 72v triangle configuration yet.

wturber said:

As a general rule, you don't build an ebike to save money. You might end up saving money in the long haul, but if you don't totally ditch the car and insurance, you won't save much. If you really want a car replacement bike, I think you need a long or medium tail that will allow you some space to build some cargo carrying capacity. Look up longtail on this forum for ideas. Use a rear DVD motor and understand that this bike won't like trail riding much. You could easily build it for 35 MPhil or so without getting to exotic but for general purpose riding, 25 MPhil is often plenty and will extend your range a lot,

$100 a month on Gas suggest about 750 miles a month driven. You can do that with an ebike, but you'll really want a comfortable and versatile bike.

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I'm going to be bringing my insurance down to almost nothing which will save me about $100 a month just that. That doesn't include car maintenance and gas. The bike will pay for itself within a year even if I have to tinker with it every now and then. Also I'm planning on renting the car out to someone so I will probably make about $500 a month on it and if they crash it I'll get a nice fat check.

wturber said:

Consider a long or mid tail cargo bike if you really want to replace a car.

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I'll be looking into this as well. Thank you for the tip.

RunForTheHills said:

3 miles at 20 MPH average will take you 9 minutes. 3 miles at 40 MPH will take you 4 1/2 minutes. Stop signs and lights could add a few minutes to that. You don't need a 45 MPH bike for a 3 mile commute. A 20 MPH bike can easily be built for under $2000. A safe 45 MPH bike, not so much. To build the 20-25 MPH bike, just buy a used mountain bike on Craigslist and buy a motor kit and battery from EM3EV or buy a cheap DD kit on eBay and buy the battery from a reputable source.

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I'm going to be using it for more than just commuting but that is its main purpose. I will look into what you said as a secondary e-bike since I will probably need two just in case anyways. Also I have other goals that require me to have a decent knowledge of making these things. Already read these posts after work.

jerkface38 said:

I'm going to be using it for more than just commuting but that is its main purpose. I will look into what you said as a secondary e-bike since I will probably need two just in case anyways. Also I have other goals that require me to have a decent knowledge of making these things. Already read these posts after work.

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A second bike sounds like a good plan, but you will definitely blow your budget doing that. The first ebike is going to be a learning experience anyway. Tread carefully renting out your car though. You have liability if you loan out your car and the other driver gets into an accident and your insurer may not cover you if you are renting it out.

https://www.nerdwallet.com/blog/insurance/car-sharing-insurance/

RunForTheHills said:

jerkface38 said:

I'm going to be using it for more than just commuting but that is its main purpose. I will look into what you said as a secondary e-bike since I will probably need two just in case anyways. Also I have other goals that require me to have a decent knowledge of making these things. Already read these posts after work.

Click to expand...

A second bike sounds like a good plan, but you will definitely blow your budget doing that. The first ebike is going to be a learning experience anyway. Tread carefully renting out your car though. You have liability if you loan out your car and the other driver gets into an accident and your insurer may not cover you if you are renting it out.

https://www.nerdwallet.com/blog/insurance/car-sharing-insurance/

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Yeah I was just thinking about doing a much cheaper and lighter ebike for the secondary one. He will have his own insurance for the car and I will be keeping track of it. It will be a cash arrangement so there will be no proof that I'm renting it out. It will probably be a 3 to 6 months agreement which will more than pay for the bikes.

I'm going to go with the one stage block big drive from the lightning rod site. I'll start with a 52v battery and then move up from there after I've done some groundwork for the 72v battery battery. I'm going to need a bunch of battery packs for one of my other projects anyways so it's not that big of a deal. Just waiting for my spot welder so I can do it at home.