Kona Stinky hill climber build

Starting my 2nd E bike build, 1st since discovering this forum 2 months ago. My first build was an electric trike for my Masters thesis about 8 years ago (https://zeept.wordpress.com/), it is amazing how much has changed in the field since then! My trike has sat dormant in the basement since then and rather than update it I feel a bike is more in line with my needs now. I live in a very hilly area with up to 10% grades and would like to commute occasionally to work which is 16.5 miles each way, the roads are pretty narrow in places and I no longer feel comfortable riding the trike on the road. I can charge at work, but I am a pretty big guy at 6'2" 290#, so I am going to need lots of torque and battery to handle the hills. I am not real concerned with top speed but I would like to maintain a reasonable speed up hills (15-20 MPH) and be able to regenerate down hills as I have several downhill sections that will burn up my brakes if I don't have a means of controlling my speed.

Here is what I have done so far:
Bought beat up 07 Kona Stinky downhill bike off Craigslist for a few hundred dollars, I have since disassembled it, stripped the paint and started overhauling the Marzocchi fork:


My goal is to place the battery in triangle and use the space below the down tube if I need more room. I have ordered 80 LG 18650 cells from tumich and will likely assemble them into either a 48V 17ah 6P13S or 59V 14ah 5P16S battery. I am building a frame case from aluminum and I am modeling it after Kepler's great build (http://endless-sphere.com/forums/viewtopic.php?f=14&t=65719). I have 2 16S D132 BMS's on order from dnmum and will order some switching power supplies off eBay for chargers.
I haven't decided on a motor yet, but I am looking towards hub motors and am currently favoring the Magic Pie 3 - I would appreciate any advice for a high torque motor that can handle my weight and hills.

Reassembled frame and replaced spring damper with Fox air shock which adds a little more room for the battery. I could not get a heavy enough spring for the old spring damper to handle my weight and the additional e-bike components, the air shock will allow the rate to be adjusted to match the heavier bike and rider.

I modeled the bike in CAD and have started on the battery layout, this is a screen shot of the current design:


This is probably my 4th or 5th battery box design already so I am sure it will change again before I start cutting metal

if this is how the battery will fit in, and if it's really such a tight fit i would double check the whole rear wheel travel with the spring removed from the damper to see that it won't hit the battery box. the top pivot point will move into the box (or at least into it's direction).

Just bought a M (15.5) 2007 Stinky with a marzocci 888 RCV on the front. Yours is likely a L or XL right? Probably affords you more triangle space than mine, yeah? I'm stalking this thread, sub'd!

markw - mine is a L (16"), triangle is definitely tight which is why I swapped to an air spring to get a little more space. izeman - you are correct about the travel, I made a cardboard template of the box and cycled the pivot through its range of motion to make sure I still have clearance:

My CAD model was off so I adjusted it to the template and now I have about 1/4" clearance for the shock now:

I love your bike. I have the same one. I still use it for DH though. Over on Pink bike there is a thread by another stinky owner who was going to strip and powder coat the frame. I see that you have stripped the frame so I would like to pass on what a tech at Kona told him:

Do not powder coat a Kona frame. It messes up the heat treatment of the aluminum. I do not know the particulars. Only that the tech was apparently very adamant about it.

I was lucky enough to find an XXL So I will be watching this build with interest regarding placement and capacity of your batteries.

If you want to work with something other than aluminum, you might want to look into Marine Board. It is easy to cut, easy to bend with heat and can be drilled and tapped. It is also cheap. At Home depot, you can usually find a 2' x 4'x 1/2" for less than $50.

If that is a Marzocchi fork, keep in mind that marzocchi motorcycle seals fit their bicycle forks and cost about half. Pyramid seals are good. I just changed the seals in a drop off 32mm fork for less than $10.00. If not a Marz, then you are on your own

Looking forward to seeing your progress.

KARCH67 said:

I haven't decided on a motor yet, but I am looking towards hub motors and am currently favoring the Magic Pie 3 - I would appreciate any advice for a high torque motor that can handle my weight and hills.

Click to expand...

Just saying Hi and welcome - will follow your built -
FYI : my stinky has a "torque oriented" hub motor. (access my built through my sig if interrested)
I believe it goes with hub diameter which allows more magnets but I don't know really to be honest : I am a noob.

I don't plan on finishing the frame - I like the bare aluminum look and going over it with some Scotch Brite leaves a nice finish.Thanks for the tip on the Marzocchi, I already bought the seals (03 Super T Pro) but I do need some washers for the upper seals - I will check into their motorcycle parts.

made_in_the_alps_legacy - thanks, I came across your bike while reading the forum, how is it for climbing hills?

Ch00paKabrA said:

Do not powder coat a Kona frame. It messes up the heat treatment of the aluminum. I do not know the particulars. Only that the tech was apparently very adamant about it.

Click to expand...

I guess this is not true. Or at least not for my kona frame which is 7020al. This needs no heat treating at all.

I don't have any idea about the heat treating or powder coating, but...I have gotten good results from primer and automotive "touch up" paint, which comes in rattle cans...good stuff. find a car where you really like the factory color, and order a couple cans from the web, or at your loocal automotive parts store?

izeman said:

Ch00paKabrA said:

Do not powder coat a Kona frame. It messes up the heat treatment of the aluminum. I do not know the particulars. Only that the tech was apparently very adamant about it.

Click to expand...

I guess this is not true. Or at least not for my kona frame which is 7020al. This needs no heat treating at all.

Click to expand...

I went and re-read the post. Here is exactly what it said:

Just a FYI for everyone from Kona. Their tech emailed me and said do not powder coat a stinky frame their aluminum can not handle the heat from powder coating. It will cause the frame to crack.

Click to expand...

Not sure where I got the heat treating from. Probably one of the voices in my head. :lol:

Even so, I think sticking with paint or raw is probably a good idea.

KARCH67 said:

, how is it for climbing hills?

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Rewording a quote from my topic, converting to imperial units :

made_in_the_alps_legacy said:

...- The gps record below is the typical hill this potential commuter will have to deal with -
- Distance : 7kms (4.3miles)
- Denivelation : +600m (1968ft)
- Representative Average speed : 29kph (18mph)
- Peak power : 2050Wp
- Consumed energy : 340Wh
- Average power : 340Wh x 29kph / 7 kms = 1408W
- Duration : 7kms / 29 kph = 15 minutes
- Miscellaneous : with pedaling, on road

Click to expand...

I am happy with the climbing performance, I initally built it for road use but since it climbed so well, I upgraded the suspension to fit my use, which is more downhill offroad oriented : climbup the mountain using road, get down using offroad pathes

side note, I have had another kona stinky from 2000, the one with the "rasta" colors, the frame cracked and got reworked, then sand blasted and powder coated, I don't know if the heat affected the frame but I doubt it (powder coating leads to 150°C-200°C temp. while metallurgical changes of alumium alloys become significant above 400°C)



sorry for flooding your topic, those bikes are great toys :wink:

Thanks for the info, 2000 peak watts is about what I figured, I have decided to change to a 5P 16S 60V pack so I can minimize the current draw through the controller, here is a picture of the new layout with the BMS:

This should also allow me to pre-assemble and test all the 5P packs separately before I put them all in series.

Hi, How is it going ?
FYI, here is my 18s upgraded enclosure (+3kW, ...and goes up to ~60kph)

made_in_the_alps very nice looking bike!
I am on hold waiting for components, still haven't received my batteries which must be on the slow boat from Poland I ordered a cheap spot welder from China and received it in 3 days so now I just need the batteries to start on the pack. I have redesigned the pack again to use standard battery holders and nickel strips - I was getting a little nervous about the time needed to solder a pack which is why I went with the spot welder. I decided to go with a 5p 8s pack on each side of the frame hooked up to a 16s BMS that will be mounted in between the packs like shown below:

you should cut the frame and integrate the box into the frame.
just find someone who can weld alloy and use 6061 or 7005/7020 alloy.

Decided on the Magic Pie3 hub motor and purchased off eBay http://www.ebay.com/itm/261548446563?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT, it arrived in a couple days and fit right into the Kona frame with no modifications. The 10mm flat on the motor match the 10mm dropouts so I don't think I will need torque arms.


Received my batteries a few weeks later from tumich and they had all welds intact so I decided I would use them as is to start. Before I commit to building a frame case I want to make sure I have enough battery, so I bought a handle bar pack that I can easily keep different battery configurations in until I settle on one. The pack also helps with weight distribution because the bike is so tail heavy with the Magic Pie hub motor. I wired the first 4P10S pack up to the BMS and charged it using a 10A 12V power supply hooked to a boost converter http://www.ebay.com/itm/111177068259?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT set to 42V.


My first test ride on level ground showed a max speed of about 15 MPH with the 37V pack, when I tried to go up a 20% grade it pretty much stalled out with a max current of 25 amps. This pretty much confirms I need to up the voltage to get more power to the motor, I am going to split the remaining pack in half to increase the pack to a 4P15S 55V pack which should work within the MP3's integrated controller 60V cutout.

I would integrate torque arms for that swingarm for sure if your going up hills.those axle dropouts arent the toughest ive seen.fun build so far.

thxs for your comments on my bike. can't wait to see your packs integrated to the frame. I guess a bigger chain ring would be welcome

Did my first test with the 15s 60V battery and what a difference - top speed on level road went from 15 to 25 MPH, hope to test on a hill later today.

Did my first extended run last night, here are the stats:

Distance : 8.3mi
Elevation up: 581 ft
Max grade: 15%
Avg: 7%
Max Speed: 27.2 mph
Average speed : 15.7 mph
Peak amps : 26.1
Consumed energy : 5.86Ah
Watt-hrs: 303.2
Watt-hrs/mile: 38.1
Average power : 303.2 x 15.7 / 8.3 = 573.5 Watts
Duration : 32 minutes
Notes: needed to help pedaling up 10% grade, couldv'e probably gone another couple miles, battery only charged to 60.5V, ending voltage 52.5 V.

It's pretty apparent the BMS is limiting my current to around 25 amps (as it is supposed to) so my peak power is 1300 - 1400 watts. I did a full charge on the pack last night to 63V, we'll see if the voltage limit on the MP3 controller lets me use it. Theoretically I have an 11 Ah pack at full charge, next test will be to see how much range I can get out of it.

Get torque arms .... the dropouts WILL fail without them.