New Member Glad I found this place

BrianMH13

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Joined
Jun 19, 2024
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4
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Oregon
Hello Endless-Sphere new member here and considering building a fairly high end e bike.

I've built a Gas motorized bike before years ago. It was with what's called a shift kit (basically the mid drive version of a gas bike) and a fairly common motorized bicycle motor. Once I worked through the quirks of the engine it was pretty fast (40mph) and reliable. It was built on a steel 700c bike frame and I set it up Cafe Racer-esque.

My car is non functional at the moment until I rebuild the cylinder head. A guy I work for suggested I get an Ebike to get from home to the city (8miles) take the bus to work and then EBike 8 miles back home in the evening. He credited me the money to get one. I had him order an Aipas A2https://aipasbike.com/products/a2-folding-ebike

It's not exactly the type of bike I'd most like to ride but seemed like it would fit the necessary mission goals.

I know hardly anything about electric systems and didn't know what was the best bike to get in around 600-700$ Within the last couple days I've been looking for what's better around the same price and it seems like there are bikes with a bit better speed and range and that look a little cooler like Amazon.com

Aipas offers 15 day free trial so if it doesn't work as well as I'd like or I decide to go another route I could return it.

I've also thought about what may be possible with 700$ and building.

I'm skilled at welding and fabrication, 3D printing and composites work. I know I could build a crazy nice Ebike but don't know what electrical components to purchase (motor, controller, etc.)

I've got a couple really nice Bike components that a lot of people have probably only dreamed about for an electric bike build. Those are a Rohloff Hub and an EZ Shift electric push button shift package.

Pretty much the nicest components I could have aside from maybe a Pinion.

Ideally I'd like to do a Dirt Bike type build set up with slightly smaller wheels and tires for street use like a HyperMoto bike. That or a Cafe Racer type bike.

I'd like 60-100 miles range and 40-70mph without pedal assist.

Not sure that the Rohloff can handle that high of speed but I've seen at least a number of ebikes running Rohloff hubs. Apparently they have a built in failure mode that is easily repaired if they get too much torque so I'm not worried about pushing it.

I'm fine with building my own battery and frame and would like to do the build with oversized components such as Pit Bike Forks, Hydraulic Disk Brakes etc.

I feel like this is the right place to be for learning/engineering such a bike and look forward to endless-sphere convincing me to build electric instead of gasoline powered.

Thank You and looking forward to maybe building a really nice bike.

-Brian
 
40-70mph, you probably want a motorcycle chassis. Bikes don't typically have a long enough wheelbase for high stability.

A dual suspension DH bike would be suitable for the 40mph range. Even the best ones start to get sketchy at 50mph.

Check my thread on the 40-60mph super hiryuu for inspiration:
Super hiryuu - A BBS02 / Leafmotor / MXUS 3kW Dual sus. bike

And welcome to the forum!
 
I felt pretty comfortable at 40mph on a steel road bike type frame but yes I would plan on a motorcycle like frame. The forks I was looking at are for adult sized Pit Bikes up to 110cc dirt bike. They are noticably stouter than mountain bike forks and have the same 15mm wheel axel diameter as modern mountain bike wheels so figured I could maybe run heavy duty mountain bike wheels or pit bike/moped wheels if necessary.

I'm not set on the build being more of a motorcycle than a bicycle just would like to start determining direction and components optimization and cost.

I'm looking at the thread you linked to now. It appears you went with a hub motor ultimately but haven't read the whole thing yet.

I had considered using a gas engine to the Rohloff and adding a Hub motor on the front for a hybrid set up which would be really cool (but complicated). I think such a bike should wait at least until I have at least another build or two completed.
 
Welcome.

Rohloff Speedhub 500/14 is rated for 130 Nm maximum input torque and if I remember correctly, 2500W gross power. I don't think you'll be achieving your speed goals within those limits, and as neptronix notes, bicycles aren't well suited to do that anyway.

Putting superhuman power and forces into bicycle components inevitably results in frequent failures and dramatically increased maintenance. That's not what you want for a commuter vehicle. Getting there every time, a little more slowly, beats going faster but not making it to your destination.

I suggest using a 1500+ watt rated rear hub motor on a cheap sturdy MTB with a suspension fork and heavy puncture protected utility tires. Aim for 30+ mph, not 40 to 70. Going too fast will wear out and break your bike, put you at unnecessary risk of debilitating crashes, confuse drivers who will cross your path at inopportune moments, and attract unwelcome attention from law enforcement. But if you use the formula I described, you can keep your cost and maintenance to a minimum, while not conspicuously violating traffic laws and customs.

If you want to go motorcycle speeds, you will spend less time and money and end up with a much better vehicle if you start with a motorcycle.
 
That leafbike 1.5kw motor can be pushed to 40mph almost continuously, add ferrofluid and it might sustain 50mph.

Chalo's on the money about that rohloff, you'll blow it at the power levels you want, you'd also need a mid drive which is more mechanically / electrically complex and much more expensive than a hub to utilize it.
 
Yeah, for 40-MPH bursts, I'd go for a Leafbike hubmotor with ferro fluid as Neptromix mentioned. He has verified experience on those.

Rohloff is a wonder piece of kit, but all of the gear ratios are close, in order to make it possible to find a close to ideal gear when climbing steep mountains. I've found that when you add an electric motor to the system, you will use fewer gears. For something like the Rohloff, you'd shift twice rapidly for each gear change you needed.
 
40mph needs 2000w to sustain the speed on the leafbike 1.5kw if you are in a tucked position, a few hundred watts more otherwise. it will be at around 85% efficiency at that point. Will tolerate that for about 5-10 miles continuous before overheating if you add no additional cooling tricks ( hubsinks, ferrofluid, or drill holes into it )

Source: i introduced you guys to this motor a decade ago :)

I don't doubt your results but can you show us a picture of this bike you used for the testing?

Remember he wants to use moto wheels and tires along with a pit bike fork and other oversize components. This along with a huge battery that will give him 60 to 100 miles range at 40 to 60 mph. Based on that I predict his bike will be much less aerodynamic than what you used.
 
The impact of rider size is larger than bike size, so give or take 200w.
Using a measuring device like a CA standalone will tell the truth on what's going on there and allow for adjustment after the fact.

Yeah, no way we are meeting that range in any kind of bike frame at that speed.

Leafbike 1.5kw is on the ebikes.ca motor simulator though, so we can estimate the range fairly accurately as long as the right parameters are input. :)
Motor Simulator - Tools
 
The impact of rider size is larger than bike size, so give or take 200w.

It's not just the size of the rider, but also the rider positioning.

In the opening post he said he ideally wanted to do a dirt bike type build. That means a very upright rider position with high center of gravity and a relatively wide stance for balancing the bike.
 
Chalo yes I basically agree about the idea of just getting a motorcycle if I want to go fast. Just wanted to say what I had to work with and would be comfortable with. Supposedly the Rohloff can handle much more than the 130nm that is published. I read an article years ago that I think said it could actually handle over 180nm around 230-40 if I remember correctly but I could be wrong.

Anyway I don't have to use it right now. I also am ok with a much more modest build like mentioned.

I've got a Cannondale M500 Hardtail with nice forks and Deore components. Thing is it's a pretty nice bike and I don't want to damage it with anything related to converting it if I was to. I'd rather keep it as is that would be a risk and buy another used bike to build electric.

So what would I be looking at in terms of $ for a set up like you suggest?

I'm probably going to build one or more ebikes at some point but for now would I be basically good enough with the Aipas or another bike in a similar price range?
 
I'd like 60-100 miles range and 40-70mph without pedal assist.
That's going to be a big battery. Look up forum member DogDipstick build. His bike seems closest to what you are describing. Not sure his range hits your requirement.

 
Chalo yes I basically agree about the idea of just getting a motorcycle if I want to go fast. Just wanted to say what I had to work with and would be comfortable with. Supposedly the Rohloff can handle much more than the 130nm that is published. I read an article years ago that I think said it could actually handle over 180nm around 230-40 if I remember correctly but I could be wrong.

The are plastic shear dowels keying the gearbox to the hub shell, which are intended to fail before the gears blow up. Maybe that's the torque value you found, but it's relevant to output torque rather than input torque. I haven't broken mine or even opened it up in the more than 20 years I've had it, so I can't speak from experience about that.

I've got a Cannondale M500 Hardtail with nice forks and Deore components. Thing is it's a pretty nice bike and I don't want to damage it with anything related to converting it if I was to. I'd rather keep it as is that would be a risk and buy another used bike to build electric.

I agree with your assessment. Don't convert a pedal bike you already think is awesome, to an e-bike. It won't come out awesome; the important qualities are different from one to the other. A good donor bike for conversion will be heavier, stiffer, simpler, physically longer and slacker, and more upright than a dialed-in pedal bike.

So what would I be looking at in terms of $ for a set up like you suggest?

Every time I price anything these days, it's more than I remembered. But if you go to Leaf Bike and check out 1500W rear motor kits (I recommend freewheel rather than cassette versions because the axle is much better), you can get a general idea. Leaf will sell you a battery I expect, but that's not their bailiwick and you probably should buy one from a battery centric seller anyway.

My current stalwart commuter bike has a QS 212 motor I bought a while back for $200, a 40 amp sine wave controller I bought for under $50 shipped, and a 2 kWh automotive battery module that I think I paid about $250 for. The bike cruises at over 30 mph even though both it and I are big (about 350 lbs together and close to 7 feet sitting up straight on the saddle), and does so at between 30 and 50 watt-hours per mile depending on how hard I flog it and how often I stop and start.

My cash outlay for that conversion is unusually low for what it is. For your specification, expect to pay more as a baseline and more yet to add features. But I think it's not unrealistic to budget $1000 plus a bike carcass and hit your lower end performance specs. Range requirements are heavier (literally, technically, and cost wise) so if you can trade off some of that, you can both save money and have a more pleasant bike to ride.

Regarding fat tire, small wheel bikes: understand that they cost range, performance, and handling qualities. The reason you never saw any before there were e-bikes, is that nobody would ever want to ride one more than 50 feet without a motor to help. So, since your performance benchmarks are high, it will be much easier to achieve them if you start with something you'd be happy to pedal unpowered. Small wheels work in your favor, if you use a hub motor. Fat tires work against you in every way unless you're trying to stay up on top of crusted snow or deep sand.
 
That's going to be one big battery to get that range and speed.
I love my Rohloff, but I wouldn't put it in that kind of set-up. Save it for something more suited. I would like to build a Rohloff belt drive ebike for trail riding, but haven't done it yet.
Interesting project, keep us updated on its progress.
 
That's going to be one big battery to get that range and speed.
It's going to have to be huge.

Example: A Sur-ron Storm Bee Dirt Bike has a 104V 55 Ah battery and yet only gets 75 mile range at 31 mph:


But he doesn't want 31 mph. He wants range to be measured at 40 mph to 60 mph.

Increase speed from 31 mph to his lowest requirement of 40mph and power consumption increases a whopping 2.15 times. This because power consumption increases to the cube (e.g. double vehicle speed and power consumption from aerodynamic drag increases 8x). Therefore power consumption at 60 mph will be almost 8x as high as 31 mph.

Of course, when traveling at faster speed the time to travel X distance is reduced but (for example) halving time (by going twice as fast) does in no way make up for nearly 8x higher power consumption per unit time.
 
Ok I understand the need to increase power dramatically for relatively little speed gain. 40-60mph isn't a necessity it's more of a loose outside desire.

I have the ability to charge while at work. 8-24mi a charge is what's necessary 30mph is sufficient though 40+ would be preferable.

I'm more likely to want a Cafe Racer type bike realistically as most of my riding will be on pavement. (I was thinking of a Enduro type bike because I live semi rural and it would perhaps be nice to be able to ride on dirt roads too)

Basically bottom line for me right now is comparing/contrasting a purchased built ebike (and what type) to building my own.

The incentive to DIY needs to be fairly strong either saving $, having much greater performance or both.

Building a bike that costs slightly more than the Aipas I ordered would be ok if the speed and range are much better.

It's just a matter of balancing time and effort to cost and quality.

As far as a bike like a 20" fat tire I understand that they won't pedal very comfortably.

Being that I've got no experience with ebikes I don't know how important PAS, ability to pedal if I had a dead battery or other matters are to me.

I'm not sure if I'm ready at this time to go with Electric. I don't really know enough yet to make an informed decision and there is a contender to electric that I'm looking at that I think offers a better option for me.
 
As far as a bike like a 20" fat tire I understand that they won't pedal very comfortably.
20" fat tire can have a normal Q factor but it needs to have a normal width (i.e. non fat) BB. That means your gearing in the back will be restricted to single speed or IGH (Shimano Nexus/Alfine, Rohloff, etc.).

A 7 speed downhill cassette (e.g. PG-720 Cassette - CS-PG-720-A1 - SRAM) + 7 speed downhill drivetrain should also work pretty good as well. This because the very narrow spacing of this 7 speed is based on 11 speed cogs and chain which allows for a greater Chain to tire clearance than is seen with normal 7 speed freewheel or cassette. In fact, the SRAM 7 speed downhill cassette is so narrow that you have to use a 11mm spacer to make it work on a regular freehub.
 
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For a solid 40 mph bike, I'd look at lightly used 20+ year old full suspension downhill bikes, preferably steel framed and heavy. Most of them won't want to tote your massive battery, but that's a relatively surmountable problem.

Or you could go for an underbone style 49cc moped as a donor. It would weigh more but probably cost quite a bit less, and be right in its element at 40 mph. Deleting the motor and transmission would afford you some kind of battery bay.
 
Or you could go for an underbone style 49cc moped as a donor. It would weigh more but probably cost quite a bit less, and be right in its element at 40 mph. Deleting the motor and transmission would afford you some kind of battery bay.

I always liked what this guy did with underbone (i.e. step thru chassis) mopeds:


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Put the brakes on here.
You're trying to get a bike to go 8 Miles to the bus put it on the bus and go how many miles to work ? You have approximately $700 for the purchase of the bike in the battery to fit on the bus.
You can't park the bike at the bus stop as people who Park their e-bike in the same place every day have a better chance of getting it stolen. This happens in college people Park their e-bike in the same place every day with a great lock somebody comes around with a 4-in grinder.
So best to take your bike to work with you.
That being said if you had a donor bike you couldn't build a bike for under $1,000 to go 35mph or 45 mph maybe.
I like the e-bike dreaming but you need to get to work and you have $700.
How soon do you need this e-bike and how soon do you need it working for work. As we have to get you to work.
I got a Sali 72v 45mm rear direct drive rear hub motor kit shipped. For 345.00 shipped it takes 3 weeks to ship. Plus a battery charger and tires. At 72v 45mph. It's a a heavy motor D.D motors don't have a lot of moving parts to break
The controller says it's does good with water is it waterproof is it water resistant ???
That's one option you could afford.
That being said there's a lot of already built bikes that'll get you to the bus stop get your bike on the bus then from the bus stop to work how far is it from the bus stop to work ?
Sorry for not talking about the dirt bike / flat track Cafe racer all in one. Thought was $700 and your main goal is getting to work to make more money for your dream build.
Glad you found endless- sphere Welcome
Remember this is a free thinking form with all kinds of ideas some good some bad some really great.
You need a 48 or 52 volt bike and there are quite a few overstocked and maybe a e-bike place that rents bikes who will sell you a rental with fall factory warranty $$$ ?
 
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I have the ability to charge while at work. 8-24mi a charge is what's necessary 30mph is sufficient though 40+ would be preferable.
That's a big change from "I'd like 60-100 miles range and 40-70mph without pedal assist." Suggest you study and tighten up your requirements to get the best help here.

I'm more likely to want a Cafe Racer type bike realistically as most of my riding will be on pavement. (I was thinking of a Enduro type bike because I live semi rural and it would perhaps be nice to be able to ride on dirt roads too)
Again, which is it?

Being that I've got no experience with ebikes I don't know how important PAS, ability to pedal if I had a dead battery or other matters are to me.
Could be a problem if you suffer a failure on the electric assist portion of the build in the middle of nowhere with no other options other than to pedal back home (or walk it). As Chalo mentioned, 20" fat tire is an absolute slug to pedal unassisted.
 
Ahh, you're OK with half of what you were looking for?

Here's my 30mph bike, soon to do 35mph. 24" rear so i can extract more power out of a smaller hub; a nice suspension seatpost and fattish tires is mandatory on a hardtail at that speed.

Range at ~31mph is 30-35 miles. Can charge to full in 4 hours.

Sound like your kind of build? a dual suspension bike would be nicer but they are challenging to fit a lot of range in.

2024-06-21 23_27_04-Window.jpg
 
I have the ability to charge while at work. 8-24mi a charge is what's necessary 30mph is sufficient though 40+ would be preferable.

Is the 8 mile trip to the bus on paved roads? Are they good paved roads? Also what is the speed limit of the roads on this 8 mile leg of the trip?

How about the 16 miles from the bus stop Into work? What is the speed limit of the roads on this part of the route? How about presence of bike lanes along this part of the route? If bike lanes are present how much of the 16 mile route has them and are they protected bike lanes?
 
I found you a bike. I couldn't get to transfer to this thread but it's in the used section. Maybe someone else can transfer it here ? It's a gray Borg Warp ebike EIG 20ah battery of you will need a new bigger battery probably 100 amp your hour or more. To get the range you want.
 
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