Looking for help before buying the wrong stuff . First e-bik

[Qc85]

I watched a video of doctorbass trike on snow last week . Now im hooked . Discovered this very useful forum but everyone seems to have many opinions and im kinda lost , so many opinions on my particular case would be nice . :lol:

I want to build my first e-bike . I want to be able to make 40 km (25 miles) with it . 50km/h average speed ( 30 miles ) would be perfect if possible . I am 230 pounds (105 kg) .

I was thinking about buying this kit off ebay
http://www.ebay.ca/itm/251931924385?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

The 72v version with 26inch tire . But i want to build my own battery , is the 48v version an easier choice that can still accomplish what i want ?

And yes its for a fat bike ! I want something that can go at a good speed non stop . I might be using it to get to work ( 30km but im asking for 40 just to make sure ) . Might even remove the pedals if it Can be reliable .

Please let me know what you think . Any suggestions will be greatly appreciated!

Thanks

 

[LockH]

"50km/h average speed" Spoken like a true insurance agent. Or medical "Professional". Or a funeral guy or... etc.




(Sooooooo 20th-Century. Sorry. Many here "urban". Maybe.)












(first Post to Alt.Planet ES? Welcome Aboard!)

 

[Lurkin]

I hope you have a fat bike to put it on....
Might want to post up what kind of bike its for..

Might be worth doing a bit more reading on the forum first.. yes there are many options and its time consuming. But the more t I me you put into deciding what you want, the more suitable the result will be. I.e. there are mid drives of various nature to consider too. Its worth test riding a few if you can too, that will give you a better of what you actually want and the differences between different options. The less you need generally the cheaper it will be, so its worth working out the minimums you would accept in real terms rather than just picking one off ebay in the budget or picking figures out of a hat.

I think you'll find people choose voltages based on what they want to achieve with a particular motor rather than ease of use or construction. Its a more relevant question of what type of battery do you want to build rather than its voltage.

I realise this doesn't answer your questions directly- its an answer to a better question- what do I actually need?

 

[Drunkskunk]

welcome to the forum.

That fatbike motor and rim might fit your needs, but unless you are an experianced bike builder, you should very seriously rethink 50kph average speed and a fatbike. I have a lot of experiance with fatbikes and speed, and can tell you first hand that they aren't well suited to high speeds. There are many problems, but the first is from the tire construction. they simply aren't constructed to maintain high speeds. the very thing that makes them so great for crawling over tree roots at 2kph makes them terrible for cruising above 35kph.

They also are made of soft, sticky, compliant rubber that gets great traction on rocks, logs, small animals, car hoods, stairs, walls, and anything that gets in your way. However, they wear out extremely quickly. I go through tires in a couple hundred miles. My tire cost averages out to one dollar per mile so far. Cheaper tires wear out faster and perform worse, so i don't save any money that way. You probably won't push your bike as hard as me, but at 50kph average, you will see a significant tire cost per Kilometer. slowing down greatly reduces that problem.

Slowing down to 35kph average would also save you battery. you use something like 2.25% less power to go 20mph instead of 30mph, that works out to roughly 35kph and 50kph.


40km is a long way. it matters greatly if you want a bike that can do "up to", rather than "at least" 40km.

 

[LockH]

Yah. Watt Stinky Guy said... Power levels re aero "drag" go off the charts (literally)

Think about going "tear drop"-shape for your ride enclosure. Think "velomobile".

(and have fun. Rolling via "tiny gas tank" - battery - an education in physics... and chemistry.)

 

[dogman dan]

Sorry to be so harsh, but the fat bike tire, at low pressure, is not for 30 mph. Snow bike yes, fast street bike no.

But a similarly large, high pressure motorcycle tire on a fat bike would be another story. So look for the motorcycle version.

Seriously, what you want to do works a lot better with a decent full suspension bike, and good 2" road tires, than any fat bike with no suspension. Or the other thing that works great is long tail bikes. Very smooth over rough pavement, and the bonus with them is the ability to carry a ton of battery. It takes a ton of battery to go far, fast.

Listen to some of us, those who can boast more than 10,000 miles of commuting.

 

[Qc85]

Thanks for the advices . Lots of things i didnt considered seemed obvious to you guys .

I will now head foward building a regular front suspension bike . I did look at some bike with front and rear suspension but there wasnt much space left for the battery . ( i dont want any mind of rack in the back ) So i think for the finish look i want front suspension would be perfect except maybe for my ass .

The kit i will buy will be the exact same thing but with a regular 26 inch wheel . Should i go with 48v or 72 ? Will it be easy to make it achieve 30miles per hour and make a 25 miles trip ?

Thanks a lot

 

[LockH]

Oh oh. There's that "R" Word ("regular").

 

[Qc85]

Oh oh. There's that "R" Word ("regular").

Are you feeling ok ? looks like your having a blast making fun of me not knowing much ... but i dont see you having any opinions on the subject , only in the terms im using .

Maybe you should go to a kindergarden and boost your ego

 

[LockH]

If you were to poke around here, MANY ES "ebikes" are anything BUT "regular". Sorry Junior.

 

[Qc85]

If you were to poke around here, MANY ES "ebikes" are anything BUT "regular". Sorry Junior.

Isnt it obvious im a " Junior " ? ... thats exactly why im here lol . No point made here buddy . You should really try the kindergarden ! x0x

 

[nutnspecial]

Hey lock, you weren't coming across right to me either. Cool your jets buddy- don't be actin like that with anyone, much less brand new peeps. Somebody's gonna really reprimnd you if you keep that sht up.
*edit- I was responding also to name-calling also, that has since been removed.

Hey qc: Welcome!
I went way more custom, 100's of hours of custom- ready to bang my head off anything hard enough to knock me out. I understand why the term 'hobby' is used now, if it were called anything else itd be some dam hard work.
Go with the kit- I'm not aware of a 72v kit though, your link had ended. A typical dd kit can go 30 mph-ish on the rated 48v- and faster on 72v. Higher volts will take more battery though, in voltage and amphours.
for 25/30 or 30m/25mph a 48v amazon/ebay kit should work fine.
about 15ah battery minimum for the distance. I had priced a halomotor @ebay b4, but ended up with hobbyking lipo instead (imo lipo is better performance for 'hobbyist')
Idk exactly what packs people are buying/making if not lipo.

ps, not sure on wth a fatbike really is. cruiser with big tires? if so, I pretty much agree, you'll want a little suspension and normal tires, or upgrade to mx rims and tires now or later. I want 2.75 shinko trials tires when I can fit them in my frame someday.
The thing that helped me the most was finding utube vids of different builds.
Good luck Brother!

 

[Lurkin]

Looks like someone woke up on the wrong side of the bed/ forgot their meds. Meh, welcome to the interwebs.

There's a real temptation when first coming on here to open a thread and hope all the answers will be written back to you in it.

The way it really works is you need to look through the forum to investigate your options, then write in your thread about what you have found. I think you will be better received this way because it will show you have attempted to figure it out yourself and are asking for help, rather than expecting answers.

The suggestion to steer clear of fatbikes for your first bike, given the speed you want to travel, is a good one.

Hardtail bikes are ok, but you need to make a clear decision as to whether you would prefer to have suspension. If you decide you would like it, its cheaper to decide now and purchase once. I went the other way and now I'm shopping round for a full suspension frame to replace it with. It may be an idea to see if you can obtain a cheap mountain bike (second hand or new) hardtail or full suspension to get you started. Hardtails are nice because they are simple but your butt can pay for it in the long run.

Which brings me back to the original point I made - if you have access to any ebike (or given you are not too sure about which bike you prefer, perhaps a bike shop or friends with bikes) to try some out. There is always the option of actually buying a ready made ebike (Haibikes are expensive, low power but pretty damn nice) as well.. But trying out in shops, borrowing friends bikes will help you decide what frame size/bike type etc etc you want to go with. Then it's a matter of working out how to power it.

If your starting from scratch you have the most options available to you. I.e. have a look into the Bafang mid drives - easy to set up and good bang for buck. Em3ev.com is a decent dealer with a good reputation on here. BUT it's easiest to install well on a frame that doesn't obstruct the motor around the crank and requires a 68mm BB. Not sure what this means? search the forum. It has been covered many times. There are other mid drives of various power and design theres a summary here:

https://www.electricbike.com/mid-drive-kits/

I have a 250w mid drive kit which I use to commute 80km per day, which it does without a hick up or drama. I have done approximately 2000kms of commuting so far and the worst that's happening is the tyre wear!

I note DoctorBass also has a DH Comp set up which is unreal. Its an awesome example of what can be achieved with a DH bike....

This site will give you an idea of the relationship between voltage, current and wattage with ebike motors...

https://www.electricbike.com/modified-hub-motor/

 

[dogman dan]

You'll quickly learn which ES members are helpful and experienced. Others are experienced, but not so much help.

Many of the "48v 1000w" kits will do 30 mph. The rest will do 27 mph. Depends on the winding of the motor, what the top speed on 48v is.

Also, your top speed will slow as the battery discharges, and voltage drops.

Re 30 mph for 25 miles. That will take about 1200 to 1500 watt hours. It's not going to all fit in the triangle of any bike, except for a few extra tall road frames.
Get what will fit in your triangle, and use that for the shorter rides. A second battery with the rest can be carried in panniers, on a rear rack, or even on a handle bar box. Lastly, the second, fairly small battery could be carried in a pack for really long fast rides.

Slowing down for the longer ride, or finding a way to charge halfway could be other options. 25 miles on what will fit in the triangle is easy, just slower.

You can reliably make it 30k, at 40 kph, with a 1000 watt hour, 48v 20 ah battery. It will be a bit large to fit in most bikes triangles.