Re-electrifying Kona Ute

[jakehrosenberg]

My electric Kona Ute has been nothing but trouble for a while now so I've finally decided to ditch all the electronics and start from scratch. Here's the specs on the bike as new: http://2011.konaworld.com/bike.cfm?content=electric_ute

I think that I'd like to be able to do about 25mph on flat ground, with a range of maybe 30 miles. I weigh 170lbs, and would generally be carrying about 50lbs of extra cargo/passenger. I will also use it for grocery store runs that could probably end up being 100lbs+ extra weight, although top speed and long range would not be needed while carrying heavier loads. I live in Seattle, so hills are an issue. I'd love to be under $1000 but realize that might not be possible and could stretch up to around $1200 or so if need be.

I'm leaning towards a mid drive setup, and was looking into the Cyclone 3000w from Luna (mainly due to the power to cost ratio) paired with one of their 52V (or possibly 72V?) battery packs. I have searched a little and haven't really seen any builds with the Cyclone on a cargo bike, and I'm wondering if there's a good reason for that. I'm not afraid of a little work to get it going and although I've never built an ebike, I am fairly mechanically inclined.

I'm open to other options, and any advice would be appreciated.

Thanks!

 

[Ykick]

Good frame to start with but nothing about the current electric system 24V/250W worth keeping, IMO.

I don’t think Cyclone’s a good choice here. BBS02 or BBSHD would be something I’d highly consider?

Maybe a DD front or rear but much harder to service tires/tubes and rear hub motor spokes will eventually fail.

A rear heavy duty Mac (I have no direct experience) might be a good match too? But, again any front/rear motor wheel build complicates things for servicing.

25 MPH for 30 Miles is somewhat unrealistic. That will require minimum 750Wh battery capacity. 1000Wh or more in order to provide reasonable reserve for hills, detours, headwind, heavy loads, etc. 15-20Ah battery packs aren’t cheap. If they are, probably fake junk cells.

 

[Drunkskunk]

I'd agree, the Cyclone is going to be more trouble. For simplicity, the BBSHD would be the way to go, for a mid drive. You could simplify things even more with a normal hub motor. a 500w MAC or a 1000w direct drive would be good. I'd opt for a rear motor instead of a front for a cargo bike for the same reason I'd want a rear wheel drive truck for hauling things. Power under the weight works best for traction.

With range, there is a HUGE difference between "up to" and "at least"
"Up to" means if conditions are just right, you do lots of pedaling, and have a nice tail wind, you might possibly, maybe get up to 30 miles on a charge.
"At Least" means if your too tired to pedal, your tire is half flat, you're carrying groceries, the battery is 3 years old and has degraded normally with age, and you're fighting a headwind, you can still rely on being able to get 30 miles.


30 mile range as a minimum is fine. 25mph max speed is conservative and fine. combined they cause a problem with battery size. A 48V 25Ah battery would work. Not impossible, but large and expensive

 

[docw009]

To easily meet your budget, I would look at a rear hub motor and battery, but a geared hub motor just seems better to me for the hills of Seattle, and a geared MAC motor is almost as expensive as a mid drive. The mid drive can use your bike's gears to pull you and the kids up those hills, so it might be the better choice.

Luna says the Cyclone is for experienced builders only. Maybe we should believe them. A BBS02 is $150 more, and I think the ease of install, plus future ease of ownership makes up the difference in price. I have this picture of a grinning Cyclone guy ripping over hills at impossible speeds, covered in mud, with tools in back pocket to adjust things as they loosen up.

In my opinion, a Bafang BBS02/BBSHD is easier to install than a rear hub motor. No torque arms to fabricate. No filing on the drop outs to make the rectangular 12mm axle slide deeper into the drop out. No wondering where to put the controller box. No rats nest of wires and bulky connectors. I believe a bike shop will take out the old BB for $10-20 if that scares you. You have to pull the pedal arms anyway to put PAS in a hub kit.

Happy riding.

 

[dogman dan]

If you go rear hub motor, the one you want is not the high rpm 1000w kit typical on amazon. It would be fine in a flatter place, but not for a big load and big hills and 26" wheel.

I know nothing about the cyclone kit, but for sure, all the big cargo bike manufacturers have switched to mid drives for very good reasons. So you are on the right track.

That Ute with a 250w front hub,, that may have been the worst mismatch of motor system and use of all time. Like putting a Honda 90cc motor in a one ton pickup.

 

[jakehrosenberg]

Thanks everyone for the tips!

What I'm gathering is that probably the best bet is to go with a mid drive, and that the BBSHD is the easiest option with the most power. It was definitely what I had started looking at in the beginning and I have not ruled it out. I wonder if anyone with experience with the Cyclone can speak to the installation, durability, and whether or not it would be a good fit? Maybe I should ask in the Cyclone topic? It seems to me that I could get a more powerful motor, and save a little money that could in turn go to a bigger battery.

It looks like for about $1300 from LUNA, these are my options:

BBSHD with a 52V 14ah battery and smart charger.

Cyclone, upgraded with ISIS BB & Luna Tic chain ring with a 52V 20ah battery and smart charger. (Or save $160 and go with 72V 11.6ah which might be a bad idea)

As for range and max speed, thanks for the reality check. I'm fine if I don't meet those exact requirements, I really just want to do the best I can without going way overboard on cost.

 

[Ykick]

72V won’t work with the Bafang BB’s. If you’re buying the battery with kit and never plan on using RC Lipo down the road, 52V wouldn’t be much concern.

However, I’m kinda regretting buying the 52V BBS02 and looking for someone local to help me reprogram it for 48V LVC/HVC?

I do my own battery packs and if I had it to do it over I’d go 48V due to my bulk charging equipment available and comfort level with 12S packs rather than 14S.

I’m also on a “mission” here too about BB chain rings. Keep ‘em smaller than you might think or what compares to stock pedal bicycles? Looks like you got that memo but for others who might go the Bafang BB route, small chainring.

Since I was replacing a 48T front Chainring on the bicycle I chose 48T for my 1st BBS02 order. Wrong choice, I've since learned 44T doesn’t limit top speed (32 MPH) under power and the only reason I didn’t opt for something smaller, 42T or less, is/was cost. Those aftermarket rings look good but ain’t no way I’ll spend that kinda cash for a sprocket.