Bought the ride! Can it be electrified?

doc007

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NY, USA
So I finally bought a bike! It’s a DH bike Kona Stab Primo 2001. It has a nice front and rear suspension and the frame looks strong. Current weight of the bike is around ~42lbs. It’s not ready to ride yet, still needs rear derailer and shifter. After I get those parts I plan to take it for some downhilling to test the integrity of everything.

Unfortunately, I’m a complete newb when it comes to e-bike stuff so any help would be extremely appreciated.
I would like to use a hub motor due to stealth factor. As for batteries, I have no idea which to get. I figure the more efficient the motor the less battery power/space I will need? Ideally I would like to mount the batteries inside the triangle space I have.

Also, ideas on the best way to construct the torque arms would be very helpful. The rear dropouts aren’t the same as most bikes I’ve seen.

Below are some pics of the bike from someone else (bike is in my friends garage right now) and some specs:

Bike: Kona Stab Primo 2001
Bike Weight Stock Config: ~42lbs
Motor: Undetermined- Something stealthy (Crystalyte/ 9c?)
Battery: Unknown- Need ~24 mile range
Top Speed: 30-40mph
Brakeset: Hayes Hydraulic Disc brakes, Hayes Hydraulic Disc levers
Rims: Mavic D321 Disc
Tires: 26 x 2.60"
 

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Awesome ride and yea can be electrified - but I think anything short of a light weight RC drive system would be blasphemy on such a nice ride :)

-Mike
 
Hi Mike,

Thanks for the compliment! I agree that RC drives are nice. Unfortunately, I don't have the machines or the technical know-how to start building components for a nice RC set-up. The other problem, is the fact that it can be LOUD. I need stealth.

I figure a hub build would be a little easier to do, HOPEFULLY. Also hubs will help with the stealth factor. I hear that Crystalytes and 9C motors are super quiet compared to RC drives.

Now it's just matter of figuring out the right hub and battery combination with a good torque arm design to keep the wheel in place.

Keep the comments and suggestions coming. I need all the help I can get. :)
 
Hey,

as a working bike mechanic, I can tell you...

Back wheel axial, 'slides' out from the right or left...then wheel falls out... good for what its made for but not good for hub motors...as your hub motor axial, don't slide...so you won't even be able to but your wheel into the tips, unless you mod you inclosed tip... that's the first real problem...

second is the axial will be bigger than normal, 12 or 15mm OD so that adds to the hassle as your hub motor's 'slotted axial' should be pretty close to normal bike size, so stopping the axial from spinning will need a good 'arm' that could take most of the load...

hope this helps

Ktronik
 
;) That bike is totally unsuitable for anything at all, and would be best donated to the Electricle project to be used for parts. :p :lol: (kidding, you know?)

Anyway, from the look of those removable rear dropouts they are probably alloy (aluminum). If I were putting a rear hub on there, I'd make new dropouts from thick plate steel, preferably clamping style like John in CR and others have made. (these do appear to be clamping style, but it does not look very large and I can't see how big the axle hole itself is or if it uses flats or not).

If you make your own you can follow the template of the originals, including disk caliper bolt-on points, but with a longer clamp arm for placing your axle, etc.
 
Looks to me like you will be using the services of a top notch metal fabricator, to get a rear hub on that. Fortunately, the way that dropout piece bolts on, you should be able to have it duplicated in cromoly in the form of a closed torque arm instead of a dropout. It will be hell to change a tire, but it should work.

What hub to choose depends on what you plan on doing, and how fast you plan on doing it. Batteries will depend on how long you plan to do it. Lipo of really high c rate could be as small as 5 ah for a huge motor. But for longer rides you'd need more of course, and the c rate could be lower then.

Might want to re think RC, since the same fabricator could make you what you need to do that. Especially if you plan on ascending a ski slope.
 
Hyena said:
cool looking bike, but what's with that rear brake assembly and rod ? Is that aftermarket or meant to be like that ?
Floating brake - isolates the suspension from braking forces.

Serious machine! What did you cost you?
 
Maybe you can remove the dropouts, install on hub motor axle, reinstall motor and dropouts as a unit.
 
mwkeefer said:
Awesome ride and yea can be electrified - but I think anything short of a light weight RC drive system would be blasphemy on such a nice ride :)

Definitely...and as DogMan said even fitting a frock motor on this
bike is going to require some serious fabbed dropouts, might
as well put this fabrication cost into a setup that will offer performance
more worthy of this bike...IMO... I think the bigger challenge is getting
batteries fitted, or should i say any reasonable amount of batteries added...
Looks like s tiny frame.

KiM
 
Could you measure the inside distance between the rear drop-outs? Some hub-motors are wide. Simple to spread the drops a few mm on some frames if needed,...maybe a problem with your frame.
 
Nice ride. Not near enough room in that triangle for enough batts to go 24 mi. but it looks like you may be able to fab a long thin enclosure below the triangle. Just have to check for front tire clearance under full compression.
 
Aluminum frames cannot be spread, not even a few mm, as the spreading will either cause it to break or seriously stress the frame.
 
:shock:

Thats a seriously nice machine and I agree with Kim on this one, this bike is itching for an RC rig, somrthing you can bolt on and off, you can cram a small pack of lipo in there somewhere I reckon.

Like this machine.

bike4.jpg


http://endless-sphere.com/forums/viewtopic.php?f=28&t=19052

Check the video for the power, you may have seen this already.

Good luck with your project, watching with interest

Knoxie
 
full-throttle said:
Floating brake - isolates the suspension from braking forces.
Serious machine!

Serious indeed! I agree with the others, this is definitely an RC drive job. I'm guessing the bike wasn't cheap so it's probably worth investing the money in a decent RC setup from recumpence or the like.
 
ktronik said:
Back wheel axial, 'slides' out from the right or left...then wheel falls out... good for what its made for but not good for hub motors...as your hub motor axial, don't slide...so you won't even be able to but your wheel into the tips, unless you mod you inclosed tip... that's the first real problem...

second is the axial will be bigger than normal, 12 or 15mm OD so that adds to the hassle as your hub motor's 'slotted axial' should be pretty close to normal bike size, so stopping the axial from spinning will need a good 'arm' that could take most of the load...

hope this helps

Ktronik

Ktronik- thanks for the post. What exactly is an "inclosed tip"? Also, what do you think would be the best way to construct the torque arm and other parts? I think I understand what you mean, however a picture would be extremely helpful. If you could find a pic or draw on the pic I posted it would be extremely helpful

amberwolf said:
;) That bike is totally unsuitable for anything at all, and would be best donated to the Electricle project to be used for parts. :p :lol: (kidding, you know?)

Anyway, from the look of those removable rear dropouts they are probably alloy (aluminum). If I were putting a rear hub on there, I'd make new dropouts from thick plate steel, preferably clamping style like John in CR and others have made. (these do appear to be clamping style, but it does not look very large and I can't see how big the axle hole itself is or if it uses flats or not).

If you make your own you can follow the template of the originals, including disk caliper bolt-on points, but with a longer clamp arm for placing your axle, etc.

haha, i wish it was unsuitable. but now that I know it has potential to be electrified i cant resist.

I think those rear dropout parts are aluminum. like the rest of the frame. Do you have a pic of the "clamping style" plate John in CR made? does this refer to the those wheels that have a lever attached to the axle? ...sorry, my bike terminology needs work.

dogman said:
Looks to me like you will be using the services of a top notch metal fabricator, to get a rear hub on that. Fortunately, the way that dropout piece bolts on, you should be able to have it duplicated in cromoly in the form of a closed torque arm instead of a dropout. It will be hell to change a tire, but it should work.

What hub to choose depends on what you plan on doing, and how fast you plan on doing it. Batteries will depend on how long you plan to do it. Lipo of really high c rate could be as small as 5 ah for a huge motor. But for longer rides you'd need more of course, and the c rate could be lower then.

Might want to re think RC, since the same fabricator could make you what you need to do that. Especially if you plan on ascending a ski slope.

Hi dogman- I hope to get it to go ~35mph. I don't think I will need crazy speed. I would like to get a ~24 mile range. My furthest commute one way is around 12 miles. I have the option to charge up over there but Im not sure how long that will take me. RC isnt bad but I need something quiet. I'm in the NY metro area and the less attention I get from authorities the better.

Hyena said:
cool looking bike, but what's with that rear brake assembly and rod ? Is that aftermarket or meant to be like that ?
Hi Hyena- That's an aftermarket part that is currently not on my bike. The pic is from another Stab Prime owners bike page. I didn't get a chance to take pics of my bike yet. Maybe this weekend I will have better pics to show of my own bike. For the most part, everything is similar. You can check out this site if your interested in a floating brake:
http://2btherapy.com/index.php/bikes/brake-therapy-floating-brake-kit
Since my bike is a 2001 they were custom made at the time, however now all the Kona DH bikes come with one stock.

buzzfirst said:
Maybe you can remove the dropouts, install on hub motor axle, reinstall motor and dropouts as a unit.
good idea, i think this will require some custom fabrication. I doubt I can find something that will be compatible. If you know of anything that will be "plug and play" please let me know.

AussieJester said:
mwkeefer said:
Awesome ride and yea can be electrified - but I think anything short of a light weight RC drive system would be blasphemy on such a nice ride :)

Definitely...and as DogMan said even fitting a frock motor on this
bike is going to require some serious fabbed dropouts, might
as well put this fabrication cost into a setup that will offer performance
more worthy of this bike...IMO... I think the bigger challenge is getting
batteries fitted, or should i say any reasonable amount of batteries added...
Looks like s tiny frame.

KiM

Hi Kim- I'm starting to see what probs I'm going to encounter. I'm going to weigh out all the options before a I make a final decision. Right now I'm bias towards a hub setup. I know, I know the "dark-side" is always more fun. But, I'm a newb and don't think I have the technical know how to pull a R/C drive off on my own. Also, I need something quiet.

spinningmagnets said:
Could you measure the inside distance between the rear drop-outs? Some hub-motors are wide. Simple to spread the drops a few mm on some frames if needed,...maybe a problem with your frame.

Hi SM- the inner distance when I measure last with my calipers looked to be 135mm. Mind you this was at night in a dark garage with the gf waiting in the car to get home. Nonetheless, I think I got a good measurement on it. Also, the frame is Aluminum according to bikepedia... more specs here: http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?Year=2001&Brand=Kona&Model=Stab%20Primo&Type=bike

torker said:
Nice ride. Not near enough room in that triangle for enough batts to go 24 mi. but it looks like you may be able to fab a long thin enclosure below the triangle. Just have to check for front tire clearance under full compression.

Hi Torker- Thanks. I was afraid I wouldn't have enough space in the triangle. I was thinking of doing a mix of packing some batts in the triangle and some along the bottom of the triangle as you suggested. I will check to see how close that front tire gets to that part of the frame. If its too close I might consider getting a smaller tire/rim.

knoxie said:
:shock:

Thats a seriously nice machine and I agree with Kim on this one, this bike is itching for an RC rig, somrthing you can bolt on and off, you can cram a small pack of lipo in there somewhere I reckon.

Like this machine.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=19052

Check the video for the power, you may have seen this already.

Good luck with your project, watching with interest

Knoxie

oh mann Knoxie, that video made me drool. :shock:
Like I said before, I would need some serious help if I go R/C.
How do R/C's compare in efficiency to hub motors? Would they use 1/2 the amount of packs a hub would use for the same distance and speed?
Also, these things are CRAZY loud. Is there a way to stealthify an R/C drive?
And how does an R/C do in the bad weather (rain, snow)?
 
doc007 said:
oh mann Knoxie, that video made me drool. :shock:
Like I said before, I would need some serious help if I go R/C.
How do R/C's compare in efficiency to hub motors? Would they use 1/2 the amount of packs a hub would use for the same distance and speed?
Also, these things are CRAZY loud. Is there a way to stealthify an R/C drive?
And how does an R/C do in the bad weather (rain, snow)?

RC setup run through the bikes gearing are more efficient than any hub setup
and really not as noisy as the videos seem to make them out to be. The bike in that video also is running dual Astros... As to expertise, you can buy all the parts from Recumpence i.e reduction drives, mounting clamps, battery boxes for lipos, motors, controllers
etc etc...just have a bit of a wait as he is always backed up with orders, well worth the wait IMHO.

If you need help, thats what the members on the forum are for and are always
happy to jump in with a solution from what i have seen in my time here....

By all means though go with a frock motor if thats all your confident will at this time, it will still
be a good ride, just IMHO not near as good as it has the potential to be.

Best of luck

KiM
 
I don't have the links for them, but lots of threads in the pics section show various kinds of fabricated custom torque plates for aluminum frames. Typically they have been done for 5203 5304 etc crystalyte motors, so look for that or x5 in the titles. Happy hunting. Lots and lots of good stuff to copy in the pics section.

I'd just remove those bolt on alloy dropouts, and see if you could get something similar made out of cromoly plate 1/4" thick. Mabye with some spacers added where needed if the thing is not a flat plate now. Then an oval hole like a tourqe arm has is added where you want the axle.

As for hub motor choice, 35 mph starts to rule out the usual choices when combined with lots of steath. x5 and 9 continent motors won't hide behind the disk rotor that good. Possibly one of the more powerfull BMC models would work well, or a crystalyte 400 series overvolted.

http://www.ebikes.ca/store/store_motors.php Here is a 406 rear. Looking at the simulator, you might need to go more than 48v to get 35 out of it.

But you want to RC motor that thing anyway. And this is coming from the guy who just won't go over to the dark side. Actually, that bike is a lot of bike for riding in the city, potholes and all. What you really want for a city bike with a hub motor, is something much cheaper, possibly much older, that has steel rear swing arm. The gold standard for that kind of bike is the mongoose blackcomb. It has nice fat 1/4" steel dropouts that a torque arm will bolt to easy.Mongoose Blackcomb.jpg
 
I too would love to see an RC setup on this... However, I'm amazed at how quiet hub motors are, and frankly, RC motors are quite conspicuous. Thats not to say that it won't be obvious that your Kona is electrically powered by the time you're done... :twisted:
 
Ok, thanks guys. From the comments it looks like R/C is the general consensus. Why?

I know this has probably been discussed in length so here a few questions I hope you can answer:

1) How much will a complete R/C build cost compared to a Hub design both of which are comparable in speed and distance? (batts, motor, controller, misc parts and services)

2) How reliable is an R/C build compared to a hub? (general use over time?, off-road use?, on-road use?, rain?)

3) How can an R/C motor be stealthified using my rig? ex minimal noise output? minimal visual detection?

4) How hard would it be for a newb :roll: to build an R/C vs a Hub? (...with your help of course :wink: )

...let's keep the discussion civil ...no fighting :lol:
 
doc007 said:
let's keep the discussion civil ...no fighting :lol:
Your requests were reasonable until this one :lol:

I'll let the RC crowd chime in from their side but really it if you're not confident it would be alot cheaper and easier to use a hub.
It'd just be a matter of having some steel plates with drop out slots cut in them made up and bolted to your frame. Or as mentioned above you could have torque plates that bolt to the motor first then bolt up to your frame. A slight hassle to change your rear wheel but then it is anyway with torque arms.
I'd remove the bolt on drop out bits, take them off to a metal fabber with a drawing of what dropouts you'd like them to make and then have them make the copy in plate steel, with all the holes and slots pre cut so you can just bolt it on and slide a wheel in like normal. Then if you want to revert the bike it's just a matter of slotting the old drop outs and wheel back on.

If you want stealth RC is probably not the way to go. If the geared puma and BMC motors were more reliable I'd recommend one of those but for offroad use neither has a good track record.

The cost for a reasonable direct drive hub set up will be about $1000-$1500 depending on what you want, where you go and how much you can do yourself.
I'll let the RC guys estimate their costs
 
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