First Build! Kona Coiler Lipo - Need Help

[keysersoze310]

Hi!
So I think I'm ready to build my first e-bike! I've been researching this forum a lot and think I have got a basic idea of what I want to build.

I found a used Kona Coiler that I'm about to buy, so before I take the plunge I want to make sure I'm on the right track with this build.

THE GOAL- Offroad bike for single track, XC, no jumps, I'll peddle a lot. Must have plenty of torque for steep hills, strong frame, very reliable, stealthy, is reasonably light, and can also go 30mph on flat road. This will require a simple Lipo setup.

Me - 135lbs, 5'6", bike and lipo noob, some electronics experience

SHOPPING LIST:
Bike - About to buy Kona Coiler Med 17" with Marzochi Bomber Super T RCV Fork, Hayes 9 brakes, Sun rims single track rims, Pictured below

Motor - Crystalyte HT3525 sensored (is there a better option out there?)

Rims - Might upgrade to 26" Sun Mammoth or MTX 39, hopefully laced with 14 gauge DTswiss spokes by a socal bike shop if I can find one that can do it

Batteries - 4 Turnigy 5000mAh 5S1P 20C for use in a 4S1P 74V configuration. Will place in battery bag in triangle (pictured below in red rectangles) . I plan on bumping it up to 4S2P in the future. (hobbyking.com)

Controller - Infinion 72V 40A controller with IRFB4110 mosfets (in bike pic as blue rectangle) - will probably limit to around 35A

Large Screen Plug in Cycle Analyst

Full Grip Throttle with Regen Button (I'd really like to get regen working)

New shifters to accommodate 7 speed freewheel with spacer washer

Torque Arms (Doctorbass)

Custom Built Wiring Harness (icecube57)

Cell Voltage Monitor: 4x Voltage monitor Cell-Log 8M 2-8S Lipo with Alarm

Charger: Hyperion EOS 1420i NET3 14S

Power Supply: Meanwell SE-450-24

So... am I on the right track here? I would love some opinions

 

[Haste]

sounds good, not much range out of a 5ah lipo pack @ that voltage though.

 

[AussieJester]

At the very least you want double the batterys you have planned...imo

KiM

EDiT. p.s rest looks good...welcome to ES :wink:

 

[miuan]

I strongly advise against a 9spd freewheel. You may have to change your shifters to go 7spd, but it's much more convenient with 135mm dropouts.
I know you're a light rider, and many heavier riders would prefer to do what you plan, but if your riding includes many steep climbs but no jumps, consider a pair of identical gearmotors like MAC, BPM or similar, run them at 20A rear and 15A front and still get good power output and much better efficiency at lower speed. I once built a Kona Stinky with rear 9C motor but it was a bit underpowered for the dirt. You can fabricate a custom torque arm for front motor that has 20mm OD to fit in the dropouts. Yeah it's more work than you expected, a bit heavier and louder than a single Clyte, but the result will be overwhelming.
You will have more trouble lifting the front wheel, but the bike will be nicely balanced, and will handle more predictably. No more boat anchor motor at the rear. Maybe if you do insist on having the regen feature, do like I did with my street build and use a front gearmotor and a rear 9c DD. But, my idea (being XC and DH rider myself) is you wont need the regen that much if you have good brakes.
Considering that you always balance charge, then instead of being obsessed with Celllogs, just use one beeper set to 3.5V for discharge. I also think your batteries are crying for double Ah. If you go geared, you can stay at 14S, have more Ah and use a single balance charger and standard controller with 75V fets. You don't really need 20S lipo if your goal is 30mph.

 

[dogman dan]

That should work, except for the small battery. You'll only get about 4-5 miles out of it. About 15 min of riding. Too short for me, but it just depends on what your riding area is like. If it's a 1-4 mile circuit, you could just pop in fresh batteries and keep going.

The one thing that might dissapoint you, is performance on hills, vs having as much as 30 mph speed. But again, a lot depends on just how steep your riding area is. I found happiness with even lower speed windings, where I only get 25 mph top speed. But I have some really steep places to ride near my house. So I go for the slower windings because they don't melt as fast as faster wound motors when climing stuff nearly too steep to walk up.

Chances are though, that the majority of your riding is not so steep, and you'll get some really nice riding on that bike. I'd strongly advise a 2812 9c like mine, but you cant buy one anymore in rear hub. I suppose you could buy a front one from Methods and swap the axles in the stators, but PITA.

If you really are going to run just 5 ah of 72v, then a Mac could be a better choice (at 15s). Better freewheeling down hills, and you won't melt one in 15 min. But you are going to get more battery asap anyway. And the mac would be less watts. I'm not convinced myself dual hub would be the most fun ride. I like being able to pull a small wheelie when getting over the larger obstacles.

7 speed freewheel. You can still have a big gear on the back for the hills so steep you have to pedal some. 48-14 will do for 30 mph. So you might need to get a different front crank.

 

[Philistine]

I was going to say that if you are intending on riding it up anything more than a mild hill, you might want to think about a HT instead of an HS. If you were going for a commuter I would say go HS, but if it is for single track mountain bike riding, I think an HS might struggle a bit if you are going to throw hills at it. I have an HS running at 20S/50amps, and even with that kind of current it is pretty weak up steep hills and creates a lot of heat. As I said, I personally love speed wind motors, because I mainly ride around town and commute, but for a mountain bike you intend to go up steepish hills with, I would go either with a HT or a 9C 8x8. Running only 1p will not only give you very limited battery range, but if you are running 40amps plus it will strain your batteries a bit.

 

[sn0wchyld]

Hi!......

If your going for 20s lipo and want a 30mph top speed, get a HT. I was able to hit 50km/h (about 30mph) on my ht in a 26' rim on 20s. I managed 60 for a brief period with the assistance of a small hill. and the HT will handle the hills far better, and heat up less.

And upgrading the AH is probably a good idea, but honestly I've gotten over 20km out of 5ah *with 24s*, witch included some 10 and 20% grades!! I did peadal allot too, but if thats what you plan on doing you may get away with 5ah (though in use, you wont want to use more than 4ah if you want the bats to last). You may also want to consider using either 5 lots of 4s packs, or 3 lots of 6s packs initially, as this will make upgrading to 24is in the future much easier - the HT is seriously quick on 24s

edit
running 10ah also means you strain the bats less - and they'll last longer.

If you want to save some $ go with an old server power supply, search google for 'tjintech' he has a guide on 'em. a 500w supply can be had for about $15, and it'll be reliable as anything.

I was going to say that if you are intending on riding it up anything more than a mild hill, you might want to think about a HT instead of an HS. If you were going for a commuter I would say go HS, but if it is for single track mountain bike riding, I think an HS might struggle a bit if you are going to throw hills at it. I have an HS running at 20S/50amps, and even with that kind of current it is pretty weak up steep hills and creates a lot of heat. As I said, I personally love speed wind motors, because I mainly ride around town and commute, but for a mountain bike you intend to go up steepish hills with, I would go either with a HT or a 9C 8x8. Running only 1p will not only give you very limited battery range, but if you are running 40amps plus it will strain your batteries a bit.

I really need to try a high speed winding - what is it about em that appeals so much? Im running my ht at 24s, and I'm scratching my head as to why you'd want a hs, given that I can hit 65km/h and climb like a maniac... what am i missing phili?

otherwise, lookin good mate. sounds allot like me about 8 months ago - right down to using the 5s5ah packs for a 20s setup, and a DJ/DH frame!! good luck!

 

[keysersoze310]

Thank you so much for the responses!

As a lot of you noticed, yeah the HT is a much much better choice. That was actually a typo, the reason I want to run 20S is so I can get 30MPH out of the HT.

sounds good, not much range out of a 5ah lipo pack @ that voltage though.

Yeah, I could really use some more AH, just not sure where to put them and keep it looking stealthy. I just might be able to cram some 5S 8Ah batteries in the frame and then the controller on top, should still be stealthy and give me a lot more range.

I strongly advise against a 9spd freewheel.

Thanks, I think you're right. I'll go 7spd and just get a new set of shifters

if your riding includes many steep climbs but no jumps, consider a pair of identical gearmotors like MAC, BPM or similar, run them at 20A rear and 15A front and still get good power output and much better efficiency at lower speed.

That's a tempting but much more complex idea. I'll need to think about that, but my guess is I'll probably stick with the single DD hub for simplicity's sake and if that doesn't work out sell it and go with your idea.

I'd strongly advise a 2812 9c like mine, but you cant buy one anymore in rear hub. I suppose you could buy a front one from Methods and swap the axles in the stators, but PITA.

Sounds great, want to sell me your's?
Yeah I'd prefer an even lower winding since hill climbing trumps speed for me, but that doesn't appear to be an option unfortunately.

If you want to save some $ go with an old server power supply, search google for 'tjintech' he has a guide on 'em. a 500w supply can be had for about $15, and it'll be reliable as anything.

Great tip, thanks!!!

this will make upgrading to 24is in the future much easier - the HT is seriously quick on 24s

I was concerned 24S might be pushing it with this motor and make it significantly more likely that I'd burn it up. If you're running 24S fine on an HT on steep hills, maybe I should rethink everything and go 24S. I guessing the infinion 72V 40A controller would need to be upgraded as well? What would be a good, small, reliable controller for a 24S setup? Maybe the 12 FET 84-132V High Voltage Racing Controller by LYEN?


So everyone pretty much agrees that I'll want more AH so I better just plan now on how I'm going to handle the extra batteries. Maybe I'll keep one set of 4 batteries in a backpack, or possibly mount it on the front fork.

Thanks so much for all these ideas everyone!! I'm really excited about building this bike but it's a bit intimidating starting out.

 

[miuan]

I'd strongly advise a 2812 9c like mine, but you cant buy one anymore in rear hub.

7 speed freewheel. You can still have a big gear on the back for the hills so steep you have to pedal some. 48-14 will do for 30 mph. So you might need to get a different front crank.

You can get the 2812 from Italy:
http://www.wheelkits.it//index.php?mypage=12&ID=119&lbSelect=

That bike will look hideous with a 48t chainring. Keep the cranks, maybe get a 42-44t chainring to go 30mph and a $25 11-30T DNP freewheel.

 

[MadRhino]

You will love this setup.

The Coilair is a lightweight FS with 36 pounds, that makes your total Ebike weight around 60 pounds.
An H series motor is a good climber with a lightweight setup, and is light enought itself to be within rear suspension damping tuneability range.

Things to watch:

The coilair is compact, an XXL has 20 in top tube and 46 in wheelbase, and that is the size I would look for to build a powerfull Ebike.

The H motor can overheat very quickly, and if you want to ride it in steep mountain trails, install a remote thermometer probe in it. Upgrading the phase wires is also a good thing, even if this motor's axle is PITA to enlarge the wire channel.

The H motor can only be fed bursts of high Amps. When fed high power for any sustained period, it is at risk to fry. This is OK when you know it, and you can feed over 5000 w when a burst of power is needed, as long as you wnow it has to be short. When your bike is lightweight, it is easy to keep the power low for most of the course. If you monitor current and heat carefully at first, you can get to know the limits of your setup and pull the best of it.

24s Lipo is perfect for this motor IMO, and a controller with 4110 mosfets is good for that voltage. A 4115 controller has higher resistance, its real advantage is only when you want to feed more than 100 v.

You have no need to pull more than 50A battery current with this motor at 100v, 40A is alot already. So, your need is not a big controller, an upgraded 12 fet does the job and is easy to fit because its small size. Having a spare controller on a shelf is a good thing, thus buying 2 small controllers is better than one big.

4 bricks of 8 Ah (24s 1p) Lipo will give you a fair range without much weight and size, makes a simple battery setup. Or you could go for 24s2p of 5A h, without compromising handling. Keep in mind that lightweight and slim is for a big part in the good handling in rough trails.

Good luck with your build

 

[keysersoze310]

You will love this setup.

The coilair is compact, an XXL has 20 in top tube and 46 in wheelbase, and that is the size I would look for to build a powerfull Ebike.

Thanks for all the tips. I'm curious though, wouldn't a XXL be way to big for me? Since I'm on the short side, I've always thought size small bikes were usually best suited for me. I figured going with the 17" Med Coiler frame would be as big as I'd want to go. I'm not too familiar with downhill bike sizing, so if a larger frame would work then that might be a good option and would let me fit more lipo in the triangle.

 

[Drunkskunk]

The Coiler is just the little brother of the Stinky, and many of us have used Stinkies for some great builds. Look through the pictures section for some of our builds, and you'll get an idea of some of the problems and solutions we have had.

Torque plates on the rear are tricky with the dropout design. There are as many ways to overcome this as there are Bikes, but it helps if you can cut metal and weld.
the batteries should go in the triangle. the bike responds amazingly well to a rear motor, center mounted battery. its slightly tail heavy but well mannered and ballanced.

Mounting the battery might get tricky. it helps if you can sew, or learn to sew your own battery bag, or make one out of fiberglass, metal, wood, or hell, you could make one out of cardboard and duct tape. what ever it takes to get them center mounted. you can mount them side by side, or even 3 wide and still have clearance for your knees.

Get a longer stem. Kona aren't hill climbers, and you'll find you're charging the bars trying to get up a hill.


Forget regen.
at best it's worth 5%. Its more effective as a brake than any actual power recovery. But if you try to regen on Lipo at the wrong time, you blow up the batteries. Research lipo fires and you'll understand why thats a bad thing to have between your legs. Get a year's experience with Lipo before you consider it. But the braking effect isn't something you can modulate like a normal brake, so its about useless on the trail.

 

[MadRhino]

You definitely want to build an Ebike larger than the size you'd ride normally, especially with a powerfull setup and fast riding in mind.

Maybe the XXL Coilair is way too big for you, and you'll have to try one to know. My experience with the Coilair design is that I would chose one size larger than mine to ride unpowered, then one size extra for the motorized build. So, if your usual size is M, it would be normal to look for an XL Coilair to build your Ebike, and if your usual size is S you'd have to look for a large.

If you have no experience with FS bikes, I suggest that you find a dealer who has the Coilair in a few sizes, so you can have the feel of the larger size and see what you will be comfortable with. If i was going to ride a powered Coilair of my size by their spec, I would need to tune it with a 6 in stem and pull the seat full backward.
Better see for yourself.

 

[dogman dan]

Get a 2812 in italy eh? I wonder where this guy is from. I have my spare one in the garage.

Chances are, his needs will be met just fine by the HT. Based on the top speeds reported, it will be pretty close in winding to a 9c 2810. I was loving dirt riding on a 2810,,,, till I got a 2812. The main thing is, don't get a fast winding for a dirt bike, unless the purpose is hauling ass down flat gravel roads. So definitely the HT, not the HS.

Take the message about good torque plates to heart. It's real important, we know by having the worst happen to our earlier bikes.

In case you haven't seen it, this is how my 2812 bike climbs on a 40 amp controller, 20s 10 ah lipo. http://www.youtube.com/watch?v=AfwdkfNZ7RQ

It always looks all flat in video, but that gully at 25 seconds is STEEP. Watch the little hill get huge as I descend the big climb mid video. That's a taller steeper hill than it looks too. At the top where it stops me cold, it's about 25%.

 

[miuan]

Get a 2812 in italy eh? I wonder where this guy is from.

This is a legit seller who has had various 9C winds in stock. He's had the motors branded for him, which indicates that he sells quite a lot of them. The price may seem expensive for an American, but here in EU, it's just right, and afaik, the only place where you can get this selection of different 9C winds. The controllers he provides (stock 9C infineon type) are very good too, I ran the 48V XC846 12fet @ 15S / 80A peak battery current and never had a problem.

 

[sn0wchyld]

.....
Forget regen.
at best it's worth 5%. Its more effective as a brake than any actual power recovery. But if you try to regen on Lipo at the wrong time, you blow up the batteries. Research lipo fires and you'll understand why thats a bad thing to have between your legs. Get a year's experience with Lipo before you consider it. But the braking effect isn't something you can modulate like a normal brake, so its about useless on the trail.

I'd have to respectfully disagree. I had regen on mine from day 1 - Just make sure you do your research first!! Yea, its worth next to nothing in terms of extending range, but I like the fact that you can use it instead of brakes, so they last longer, and you get less break fade on big hills. You definatly want a switch for it though, the 'auto on' feature is crap, and increases the risk of burning the motor.

I need to open mine up and see if the windings look at all toasty (and install a temp probe) - I run 100v at 45A. but I only use WOT for small bursts, and never from a standing start (wind on the throttle rather than FLOOR it) - so far the motors been pretty cool, though I've only monitored outside temps...

I was concerned 24S might be pushing it with this motor and make it significantly more likely that I'd burn it up. If you're running 24S fine on an HT on steep hills, maybe I should rethink everything and go 24S. I guessing the infinion 72V 40A controller would need to be upgraded as well? What would be a good, small, reliable controller for a 24S setup? Maybe the 12 FET 84-132V High Voltage Racing Controller by LYEN?


So everyone pretty much agrees that I'll want more AH so I better just plan now on how I'm going to handle the extra batteries. Maybe I'll keep one set of 4 batteries in a backpack, or possibly mount it on the front fork.

Thanks so much for all these ideas everyone!! I'm really excited about building this bike but it's a bit intimidating starting out.

I live in a fairly hilly area, so the HT handles it well, but I want to stress that I always assist the motor up hills, and I still check the temps regularly (though less than when I started now that I have a 'feel' for it). The 20% grade I've done just once (it has just under 1km or so of 15-20% and another km or so of 10%) I pedalled like heck and at the top I let the motor rest for a while, but the outer temp never came above 45C (~25C amb.). If your doing allot of really steep long hills then 18s or so may be better, and still allow an easy upgrade later.

My controller is a standard lyen 12 fet, with modded regen/ vsence (bout 15 min work). So far works great, only gets warm after hard riding or allot of regen. If you get a 12fet, then I'd also reccomend adding a temp probe to the FET side, as mine does seem to get warmer on 24 than 20s.


Now that I think about it, use 4s or 6s bricks so you can go with 20/18s to start with, and buy enough that you can change to 24s in the near future. A - it gives you somewhere to go in terms of power, 20s is fun, 24s is mad . B - it gives you a chance to get a 'feel' for the motor and controllers heat before you up the watts.

Get a 3 speed switch too, the throttle at 100% on 20s was fairly snappy, and is crazy on 24s - using the 66% mode means that its easier to manage torque on tight trails.

 

[keysersoze310]

You definitely want to build an Ebike larger than the size you'd ride normally, especially with a powerfull setup and fast riding in mind.

Maybe the XXL Coilair is way too big for you, and you'll have to try one to know. My experience with the Coilair design is that I would chose one size larger than mine to ride unpowered, then one size extra for the motorized build. So, if your usual size is M, it would be normal to look for an XL Coilair to build your Ebike, and if your usual size is S you'd have to look for a large.

That helps a ton, thanks! This means I'll be throwing my coiler idea out the window, haha. I'm between and M and S generally, so I probably want a L at minimum or XL then. I'll try to find an lbs with some similar kona's (checked one already and they had very little) but I have so little experience with bikes that I'm probably not going to be able to tell much difference. There is a used 18" Stinky I have my eye on as well, and I just played around with the space in the triangle on photoshop and there is quite a bit more room to work with...


For regen, I mainly wanted it for braking versatility and not so much the added power. Its not a big deal, but if I can get it to work that would be nice. I guess that would mean adding steel torque plates, which is tricky since I don't weld or anything. I was hoping doctorbass's super torque arms would fit the bike, but people have had problems with those and regen working with the HT, so I'm at a loss. Its not a big deal and I want to keep things simple so I'll probably just pass on regen for the time being.

No matter what I'll be adding a temp sensor, soo very worth it. And 3 speed switch.

I need to do some research on those lower winding 9c's, they weren't on my radar. My impression was they couldnt handle as much watts as the crystalyte.

 

[dogman dan]

Pardon me, I meant what continent is Keysersose on.

I haven't seen much that would convince me that the H motors can really take a lot more watts than a 9c type. Both seem to be meltable. The slower windings will tend to make a lot less heat climbing hills though, and partly by not pulling as much watts. In the slowest windings, it's going to take quite a hill to get em to draw 3000w. So since the motor climbs better, it climbs closer to its faster speed, draws less wattage, and makes less heat. I've run my 2812 up some vicious hill for 4 continous miles without it overheating, and it hot weather. That was on the 40 amp controller too! Pretty much was drawing 1500-2000w continuous.

So whichever motor you choose, the slow winding is the key for a good trail bike in my opinion, or the use of a Mac or similar larger gearmotor. I like the dd durability, and as you can see in my vids, I need it to ride the rocks and gullies.

 

[Thriller]

Thanks for all the info, I have a coiler I would like to build up as well.