Future ebike build [description and parts list]

[kauppinen]

Hi!

This is my first post at ES I have spyed alot of different e-bike projects in here and I'm very interested in building one myself.
I'm planning in near future to build a ebike that is fun, reliable(will be used for 5-7years) and relatively light weight (not like friction drive light more like 20-25kg).
Also high power reserve in the batteries is a must, because like you all know the appetite grows with eating. Decent "mileage" should be achieved also(20-40km assisted).
The frame I'm thinking that could be perfect for this conversion is my fully suspensioned focus cypress pro.

The usage of the ebike would be day to day riding for ex. to work and recreational like offroad riding.
I have chosen these parts to my project (can and will be changed if necessary):

Motor: Mac 8T REAR from em3ev.com
Controller:9 fet IRFB4110 Infineon Controller (current limit 30A, programmable) from em3ev.com
Battery: 14s4p li-ion 48V 10.4 Ah battery, made from US26650VT cells (continuous 10C rating and 20C burst) from a chinese dealer. Those are 3.80 dollars/cell+shipping(includes battery weldings).
BMS:14S 40A Li Ion BMS from em3ev.com
Charger:Aluminium Case Charger 58.8V 5A,14S Li Ion/NCM from em3ev.com
Misc: Throttle etc.

Top speed should be around 40-50kmh, which is plenty for my taste. I like that ebike has more umph than mph .
The motor will be driven @ 48V and 20Amps max to maximize the batterylife.

What do you think guys, are my goals reachable with this setup? Should the controller be a lyen controller or is this one fine? My budget is around 1K euros or 1.3k in US dollars, I live in finland so the shipping costs might end up killing me.

 

[arkmundi]

Your approach seems pretty right on to me. em3ev.com is reputable highly regarded vendor, so ask him whether the "kit" components play well with each other. good luck!

 

[DAND214]

I think you will love the MAC. I have 4 at this time.

Why not get it all from PAUL?

Will the trianle pack fit the frame or is it small due to the shock?

Dan

 

[kauppinen]

I think you will love the MAC. I have 4 at this time.

Why not get it all from PAUL?

Will the trianle pack fit the frame or is it small due to the shock?

Dan

Hi, Dan!

Lol, I migh become addicted like you . Have you had any problems with them? Any bb-drive conversion experiences?

I have to look the dimensions more precisely once more. I think the main issues were the power giving capability of those cheaper cells (only 25A total continuous), I think they might become a bottle neck in the future. Also the estimated cycle life is pretty low(500-700), although it can be doubled by using 80% of charge. The form factor is a definetly a plus though for the triangle pack.

Your approach seems pretty right on to me. em3ev.com is reputable highly regarded vendor, so ask him whether the "kit" components play well with each other. good luck!

Hi, arkmundi!

Okey phew, I think all those hours of watching ebike projects from youtube/ES are paying off . I'll ask them. Thanks^^!

 

[dogman dan]

10T mac will be better on steep trails, and for urban riding with lots of stops. Top speed aint everything.

You can't build to do both, fast on the street and climb the mean hills, on a tight budget. But you can still have 25 mph and climb well.

Don't misunderstand, the 8 t will still climb hills that would kick your ass to pedal up. It just gets hotter and range is shortened on steep hills. Just think hard about how much you want it to be a good trail bike, and choose the 10t if that is the important thing.

 

[ridethelightning]

make sure, if you plan to get a cav3, that the controller from Paul is fully compatable with it otherwise F%*************************GHJH headache!, cant limit ANYTHING.

Thats my 2cents.

perhaps get some spare nylon gears too if you want to climb hills a lot :wink:

 

[23skidoo]

I'll stir the pot:

You won't get umph with 20 amps 48v.

With my bmc/Mac, I have to trade umph and reliability hence the advice to have extra gears on hand.

Use more voltage, amps, and direct drive. Then, like when you drive your car, use much less than full throttle for normal operations. Pedal routinely, and keep the speed down for safety, health, and range.

The weight of the bike matters with handling on the road, but the weight difference among hub motors won't matter compared to the battery. The weight also matters for those who carry their bikes up stairs often, or are not so strong and need help to lift the bike, but the extra weight of the direct drive is well worthwhile otherwise.

Ultimately I have found my bikes more a form of transportation than recreation, so you may want to consider what you want to lock up as well as what you want to ride.

Enjoy!

 

[ridethelightning]

+1

gotta say i love my direct drive, crystalyte h4065. nice wide stator so heaps of torque, hits 50k at 48v on the flat. (if i was building it again id be looking to 60v.)

i doubled up my amphours to 20AH though, so went to 2p pack of headwaylipo4 10 ah cells so i didnt have to work the cells so hard to get the amps for bursts of speed or hill climbing with 50-60 amps. it weighs in a bit but i wouldnt go back.you can see some picks of my bike on the"need stealthyness ideas thread"

with liion you should be able to get a similar battery to be heaps lighter/smaller, and give higher discharge.

my experience is that sooner or later, if you skimp on the power, you end up holding the throttle down full all the time and wish you had more herbs.
so might as well face up to it sooner and get a fat uber battery
its the acceleration thats addictive more or as much as top speed for me :wink:

ps.i like the frame you posted, looks like a winner.

 

[kauppinen]

Hi all!

Firstly thanks a lot for you comments I had to suck the wisdom out of them for a moment.

Hmm maybe I'll go with the 10T as dogman suggested, 25 mph/40k is still a lot and added robustness during hill climbs is welcome.

The Paul's triangle pack will fit in the frame but the battery bag won't. This plus the fact that max amps are 25 with the pack of my liking means that I'll continue with the US26650VT cell pack.
I have to make/purchase a fitting lockable bag (as ridethelightning suggested).

A 9c/crystalyte hubmotor is also very tempting for the sheer power of those things but I like the form factor of mac/bmc more. This can and propably will change in time.

How about the noise level with the mac, is it irritating or does it just blend in with the whirling wind?

ridethelightning, lol. You're driving with over 2kW mini ebike, must be quite an animal to ride. Yeah the battery is not that subtle

I think that 1 kW is enough for starters since the only ebike I have driven is my dad's small'ISH 250W pedelec/ebike, that thig is so boring bogging all the time, weighing in a ton and going 20km/h max. so to me a 1 kW and 40km/h ebike will create lots of funs per hour for manymany hours .

ps. yeah, the frame is awesome hydraulic brakes and 27 speeds the only negative thing about it is the front shocks that are totally stuck, have to replace them before this baby gets bolted on.

 

[kudos]

Hi all!

Hmm maybe I'll go with the 10T as dogman suggested, 25 mph/40k is still a lot and added robustness during hill climbs is welcome.

I get about 27mph on my 10T Mac using 12S Lipo charged to 4.10V 49V HOC running down to 44V,

Kudos

 

[kauppinen]

Hi all!

Hmm maybe I'll go with the 10T as dogman suggested, 25 mph/40k is still a lot and added robustness during hill climbs is welcome.

I get about 27mph on my 10T Mac using 12S Lipo charged to 4.10V 49V HOC running down to 44V,

Kudos

Hi kudos,

okey, thats great. how heavy is your system? I can expect similar figures from 14s li-ion.

Btw just ordered new front shocks (Rock Shox 30 Gold TK Solo Air) from bike24.

Kauppinen

 

[kauppinen]

Hi all!

My fully mtb got stolen last week so, the original plan will be changed..

I'm now designing a 350-500w ebike for a friend, she has a hybrid bike and I'm thinking a similar build with a regular 36V12ah or 48V10ah pack.