Replacing pedals with motor?

GoldenMotor.com

Derleek

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Oct 10, 2019
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So I'm starting to plan a new e-bike build with the idea of taking the pedals completely off and connecting a motor straight to the crank shaft. The reason I want to do it that way is so I can use the existing gears on the bike as a sort of transmission. I haven't really been able to find anything about how to connect the motor in this fashion, so I thought I'd post here. If anyone has any ideas or tips I would love to hear them.
 
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indian22

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Dec 31, 2014
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Look into electric shifter kits and mid-motor drives to start learning things, as there is tons of information about doing these e-bike conversions and keep the pedals.... and have fun!

Rick C.
 
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Derleek

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Oct 10, 2019
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Look into electric shifter kits and mid-motor drives to start learning things, as there is tons of information about doing these e-bike conversions and keep the pedals.... and have fun!

Rick C.
Thanks, Rick.

I did some more research on mid-motor drives. That's essentially the type of design I'm going for. This is going to be a super low-budget build so I'm trying to put together a few cheap parts (and willing to put in the extra work that comes with that) to make a reliable rider. I'm having trouble finding motors and batteries online that aren't part of a kit or way out of my price range. Do you have any go-to websites for motors and/or batteries?

-Derek
 
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indian22

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Derek the advertising sidebars have vendors that support our forum, just start clicking on these and keep learning. I'm not a big fan of mid-drives, but I've seen some awesome and expensive builds using them. When price is no object people have more options, but when you're building on a budget compromises have to be made. I don't compromise on builds as money isn't a problem and I still prefer e-hubs. I now have four of them. I also have a mid-drive that is still in the box that I bought before I learned things and one day I might actually use it on a bike...but that's doubtful.

Rick C.
 

fasteddy

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Feb 13, 2009
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Hi Derek,

If your bike doesn't have pedals it's classed as a motorcycle and will have to meet where ever you live standards for driver license, insurance, plates ect.

Legal limit in the U.S. is 750W motor. In Canada it's 500W. As Rick said look at the vendors at the top of the page. Sick Bike Parts sells a good mid motor. I'll post a link to a chap who sells batteries and connectors for a make your own battery. No spot welding needed since everything bolts together.

If your on a super low budget electric probably isn't for you. It won't be hard to have a $1,000 plus into a mid drive and battery. Sick Bike parts has shift kit for two and four stroke engines.

Battery source, all things ebike, http://lunacycle.com/
Do it yourself battery. Battery kits

Hope this helps.

Steve.
 

indian22

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Dec 31, 2014
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Steve thanks for adding the battery link that's the way I plan on building my batteries. I've spent well over a grand on lithium this year and it just makes sense to build my own 52v 20 amp packs. BMS is a must and I've yet to decide on a supplier for these. So suggestions are as always welcome.

Rick C.
 
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fasteddy

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Your welcome Rick. This is the way I'll build a battery as well. What I like about it is that if a cell does go bad you can get at it and remove it without having to pry the spot welds apart and then have to weld it back together. Price savings a welcome as well.

I believe they sell those as well but I'll look around and see what suppliers Information I saved

Steve.
 
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fasteddy

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Rick, I've looked around my bookmarks on the computer and I didn't find anything I'd saved for the battery BMS. If you look at the header on the page I sent you you will see what they sell other than the battery holders . BMS for sale there as well as batteries.

I did find one where he is building a 52v battery. DIY "Mighty Mini" 52V battery with new V2 battery building kit!

This what I plan to follow when I build my battery.

Steve.
 

indian22

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Dec 31, 2014
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Thanks Steve I think I've some research left to do before I tackle my first lithium pack build so thankfully I'm not on the clock to produce one in any given time frame.

Rick C.
 
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Derleek

New Member
Oct 10, 2019
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Hi Derek,

If your bike doesn't have pedals it's classed as a motorcycle and will have to meet where ever you live standards for driver license, insurance, plates ect.

Legal limit in the U.S. is 750W motor. In Canada it's 500W. As Rick said look at the vendors at the top of the page. Sick Bike Parts sells a good mid motor. I'll post a link to a chap who sells batteries and connectors for a make your own battery. No spot welding needed since everything bolts together.

If your on a super low budget electric probably isn't for you. It won't be hard to have a $1,000 plus into a mid drive and battery. Sick Bike parts has shift kit for two and four stroke engines.

Battery source, all things ebike, http://lunacycle.com/
Do it yourself battery. Battery kits

Hope this helps.

Steve.
Wow that build your own battery kit would be way cheaper than buying a huge pre-made battery, thanks for that link. All these messages have been really helpful in my design process. I hadn't even considered that no pedals would change the classification of the bike. Keeping the pedals on is definitely the way to go. Thanks for all the help everyone.

-Derek
 

fasteddy

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Feb 13, 2009
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British Columbia Canada
Thanks Steve I think I've some research left to do before I tackle my first lithium pack build so thankfully I'm not on the clock to produce one in any given time frame.

Rick C.
Your welcome Rick. Just trying to get the word out as to what is available. Hope it helps when the time comes.

Steve.
 

waynesdata

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Jul 10, 2017
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Rick, I've looked around my bookmarks on the computer and I didn't find anything I'd saved for the battery BMS. If you look at the header on the page I sent you you will see what they sell other than the battery holders . BMS for sale there as well as batteries.

I did find one where he is building a 52v battery. DIY "Mighty Mini" 52V battery with new V2 battery building kit!

This what I plan to follow when I build my battery.

Steve.
I also like the EbikeSchool channel. Looking at building a small battery to run lights.
 

indian22

Well-Known Member
Dec 31, 2014
4,722
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Oklahoma
Wow that build your own battery kit would be way cheaper than buying a huge pre-made battery, thanks for that link. All these messages have been really helpful in my design process. I hadn't even considered that no pedals would change the classification of the bike. Keeping the pedals on is definitely the way to go. Thanks for all the help everyone.

-Derek
Old guys helping new guys and each other along the way with helpful suggestions is what keeps forums healthy and alive. None of us knows it all & no one should pretend otherwise. Have fun leaning things Derek I know I do.

Rick C.
 

indian22

Well-Known Member
Dec 31, 2014
4,722
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Oklahoma
Your welcome Rick. Just trying to get the word out as to what is available. Hope it helps when the time comes.

Steve.
That time is soon Steve. Battery tech is a by the fire type winter activity and can be done bit by bit no matter the nagging of old Arthur and his demon buddies pain & suffering.
The Lego style battery construction will lessen the tactile demands of suffering hands eliminating the tedium of soldering scores of spot welds...I find that work mind numbing and therein lies potential for mistakes. I don't mind easy on normally tedious tasks.
I'm thinking two, 52volt, 20 amp packs with BMS will occupy my initial efforts

Rick C.
 
Jan 24, 2012
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letterkenny, ireland
So I'm starting to plan a new e-bike build with the idea of taking the pedals completely off and connecting a motor straight to the crank shaft. The reason I want to do it that way is so I can use the existing gears on the bike as a sort of transmission. I haven't really been able to find anything about how to connect the motor in this fashion, so I thought I'd post here. If anyone has any ideas or tips I would love to hear them.
Derek, I've been toying the idea lately that's darkly similar but different to yours, a tribrid mid drive bicycle, and the way I am planning basically involves a few parts off sick bike parts, specifically the freewheel cranks, a freewheel and 1 bicycle sprocket, the mid drive part for now is going to be a kids ride on scooter( 24v 200w) that I expect to burn out eventually as I pulled it from scrap, and use the drive sprocket and freewheel it's on, on the cranks until the freewheel gives out and then mount up the better freewheel, hope this helps, I know it's a little late