KMX Cobra

[Ypedal]

with carefull eyeballing.. i got both sides very close to equal.. a bit of work with a flat hand file and this sucker dropped into the frame perfectly !

kmx25.JPG (40.95 KiB) Viewed 427 times

I'm now working on a torque arm for the inside of the frame on the left side and mounted a 20x1.95 hookworm tire .. tomorrow i may fire up the welder and finish the torque arm properly.. then i can bolt it up and plug in a 48v controller for a powered test !!!...

[Doctorbass]

Nice job on the axel !

Ypedal, if you really want to enjoy a minimum confort i suggest to go with a 2.5 or 3.0" rear tire!

The dual ply hookworm 24 x 2.5 also availlable ay chainreactioncycle is the best.

On mine i just ordered a set of two Vee Rubber V282 20 x 3.0 tire I love them!!!

I also burn them .. that's why i need some spare tires!

Bt for the dront wheel even if you find some larger rim, .. I guess that the one you have for the zero ( 44mm wide) are just perfect! .. I strongly recommand these Vee rubber. They are more popular in europe but i found a seller on ebayt that still have some!.. he is located strangely in SoCal......

54.99 for two tires + shipping



http://www.ebay.com/itm/150781607805#ht_500wt_1413

I'm using one on my rear 5304... on one of these great zero motorcycle rim you sold me

The match is perfect!

Doc

[Ypedal]

heh heh... I slapped on a used 20" x 1.95 hookworm for the time being, i need to start using my tower of tires, it's getting tall..... i figure i'll burn this one up quickly so may as well put on a used one !

I tried spinning the axle by hand and could not budge it, weird, as i can usually spin up most hubs by hand. .. put on a wrench and it spun over but there is obvious non-expected friction going on.. this motor has all of maybe 20 minutes of use on it since new... never in rain.. soooo...

[Ypedal]

Went digging into my stash and found a NOS old school analogue clyte controller..

kmx27-controller.JPG (40.21 KiB) Viewed 391 times

This is the last one from my shipment, i quit selling them, so un-reliable they were costing me more money in return shipping than they were worth, labeled as 72v but only work at up to 48v ( i blew up 80 % of the batch trying them at 72v.... but reliable at 48.. argh. )

kmx28.JPG (52.08 KiB) Viewed 391 times

I have 2 that were re-built by Mr.R in ontario that are still in use, one is on the BMX the other on my Chaos, both run at 100v and 50 amps, rock solid .. but the originals were baaaad...

It does have a reverse switch tho !! .. convenient on a trike i think.. and cruise .

[Ypedal]

But, it's ALIVE !!!..

after spinning on the bench for a minute, it's back to normal, bearings just needed a good run-in..

[Ypedal]

Game ON !!..

Should be able to test ride this sucker tomorrow !!!

kmx30-game-on.JPG (51.85 KiB) Viewed 385 times

edit : i've been playing around with controller and throttle etc placement, mounting stuff to a trike is a walk in the park, loads of room to bolt and mount stuff to, I"ll be able to fit a HUGE lipo pack on this thing !!!!

This is likely going to be the first rig i can justify the use of an X5 on.. considering all i have available in my parts stash, i'm running a xlyte 4 series on my daily driver and a 9C on my e-BMX, i've had an X5302, 2, 4 and 5 on hand all these years and the chopper got the most use with a 5304 but not that much.. they are rediculously heavy for sub-5000w setups..

I can even conceive of a BMC geared motor on this as a good option, would shave 20 lbs off the machine and work just fine for the speed i am willing to go on this.

off to HK for Lipo shopping ...

[Ypedal]

Ok, no pictures or videos yet but i have gone on my first electric trike ride !!!!!

Was not an easy, out the door i go, thign either...

After bench testing the throttle, controller and motor, i was confident it all worked.. so i plugged it up to the trike and electrical taped the bits on for a quick road run...

Plug in battery... and zip.. zilch.. nadda....

Now, this controller is an old 4 pin model throttle, the new throttles are 3 pin, ( the 4 pin is for LED throttles )

I lucked out when bench testing and plugged in the right row of pins.. but when transfering to the bike i unclipped the throttle and had to plug it back in.... ( more on this later ).

Alrigh.. so yeah.. it's now 9pm, pitch black out there.. i should be out riding but noooooo..

Fine.. get another controller from the dual speed 20 amp batch, plug that in.. with both throttle combinations.. no go..

ok.. back up stairs to the stash room.. i get a few more throttles ( I have a box of 50 ..so you know.. ) .. still nothing.

Dig out the Lyen testing rig, original throttle.. i'm using both dead.. new un-used throttle.. works.. wtf.. ok.. fine. so i go upstairs and get a new motor ( 4013 clyte ) ..

plug that in but this time making sure to use the other combination of pins first time out and WHAMO .. we got juice !!!.

So now i'm up to my knees in parts.. shove all that over.. plug original controller and new now tested controller back to the trike.. a whole bunch more eletrical tape.. slap a 48v lipo pack on this thing and dress warm.. out i go !

Flashlight in one hand.. throttle, brake and steering with the other.. chain derails right away.. but F it. .. Y Pedal i say ! when you gots a motor !!!

aw man this is fun.... totally needs a thumb throttle.. twist is suicide on this type of steering..

Had no CA so did not dare go far on an un-tested 5ah lipo.. 72v will be plenty fast.. and 100 amps should provide donut making power...


hooked...!

[Ypedal]

Ok.. so today i decided to deal with the chain issue..

The Cobra has 3 speed front, so with the big fat X5 on the back i really only need a single speed at the back, and that's all the room i have to spare with the centered hub and cut axle..

So after adjusting the derailleur to perfection i tried pedaling and quickly found out i had a problem on my hands, after much noggin scratching and observation, i found that the chain is not engaging the teeth on the single speed freewheel properly, at all, the chain rides high and skips at the slightest pressure on the pedals.

Well, i figure that by taking my dremel i can " massage " said freewheel into working, an hour later i have the chain kinda engaging properly but still not right, however i discover another issue, the damn thing wont ratchet as it's supposed to and just slips...

Alright.. no problem. i got a dozen of these damn cheap china no name freewheels so i cut the tape, again, disconect the motor, pop the motor off the bike. run in the house to get my freewheel tool... uhm.. yeah.. i reamed out a multi speed tool already but never did the single speed tool.. so it wont fit over the axle.. and this is one meaty tool... oh my kingdom for a lathe....

But, since this freewheel is toast to begin with, what the heck.. o'l screw driver and hammer trick.. bing bang.. off it goes..

Now, i have a really expensive Eno 18t from my RC bike project, i checked the teeth of this with the chain and it meshes perfectly !.. sweeet !.. only problem is that it has a damn 10mm shaft adapter spun on it, aluminum, jammed in there royally, spent almost an hour with my neighbor trying to get them apart.. no luck.. so this goes back in the " RC parts " bin..

I grab a new freewheel, of the cheap no name variety, but since it's not attached to the motor, i can work the teeth before installing it on the motor !.. bonus.. so 30 minutes later.. i have it almost meshing.. but still not right.... i'm not going to do this..

Tomorrow.. i hit up the bike shop for a proper freewheel.. shimano or similar.. then the motor can go back on.

[Doctorbass]

Man what a complicated story!

Ypedal.. I know you will be amazed how fun this is when you'll have solve all these problem.. what a karma you have!!

Even if you need one of these crystalyte 12 fets digital controller i can trade it with some of your stuff. It's brand new in the box!

i'm looking forward for your next tests !

Doc

[knoxie]

I am glad it wasnt just me who couldnt get on with the full grip throttle on the KMX! it was scary, thumb throttle is the only way! looking forward to seeing some video and pictures

[Pure]

So why are you filing down freewheels? Is because the chain has funky spacing?

[Ypedal]

Update Time !!

With pictures this time.

So here is the situation....

kmx31-chain.JPG (67.8 KiB) Viewed 586 times

No.3 is the original cheap chinese i been messing with..
No.2 is the mess i made yesterday from a no.3
No.4 is an ACS 14t i picked up today at the local bike shop
No.1 is a no.3 that i fixed !!!

* The tape on 1 and 2 is just to keep dust and grindings from the insides of the units....

So after a dissapointing day yesterday not being able to resolve this.. i had to go to my nephew's 3rd birthday party across town at my sisters, so i used the RC bike to get there and on my way home i swing by the local bike shop with a piece of chain and my problem freewheel..

Here is the problem :

kmx32-chain2.JPG (35.14 KiB) Viewed 586 times

Above, see how high the chain rides on the teeth.. ( the picture actually makes the problem obvious, i should have taken pictures yesterday... )

[Ypedal]

Here is how the chain should fit.. on an ACS claws 14 tooth..

Problem here, is that neither did i or the bike shop owner guy realize that the threaded inside of the units are not the same diameter, this will NOT fid a crystalyte thraeded collar.. it's to small.. wtf this is supposed to fit i have no clue.. but mofo it dont fit what i needed ..

[Ypedal]

This is no.2 i mangled yesterday, trying to grind down the teeth a step at a time with no luck.... this is where i gave up..

[Ypedal]

so here is the problem.....

the ACS = 2.34mm :

kmx-35-acs235.JPG (42.29 KiB) Viewed 585 times

vs

cheap chinese 16t freewheel = 2.85mm :

[Ypedal]

Solution, for now, was to take the angle grinder and shave the thickness of the 2.85 down to 2.3x , put the fw in a bench vice and carefully worked it down until :

[Ypedal]

Now, after all that work, i spun the modded cheap chinese fw on the hub, bolted the motor back onto the KMX, ran in the house grabbed a 48v 5ah lipo pack in a hurry and taped it to the bike..... slapped a CA on there ( thank god ) and off i went..

As soon as i got going, i noticed my 12S pack voltag was a curiously low 40v, should have been 50v.... but in the heat of the moment i throttled on with a shit eating grin from ear to ear

Then i hit me.. oh jezus.....i picked up the wrong lipo pack..... I had a pack ready to go, ballanced and fully charged, but the other ( idential looking was right next to it with a less than 3v cell in it !! while the other 11 were at 4v + !!!!!!

Pedaled home, see, good reason i got the pedals working as a priority !

cut it off the bike, ran into the house.. grabbed the right pack. set the previous one in the middle of the driveway far away from anything flammable, deal with that after.. strapped the full charged pack on the bike and put on a helmet and gloves.... !

OMFG..... this is so much fun, it's even better than i expected, even with a puny 48v 35 amps this X5305 in a 20" rim is smoooth as silk..

I went up the road alongside 80kph traffic, a few figure 8's in the honda/ harley davidson dealership parking lot, zipped back home and up the dirt track alongside the CN rail service road .. ( BBbBbbbbBbUuuuuMMmmMMmPpPPppPP YyyYyYY ) .. but still fun !!!.. these KMX's are sturdy machines.. i weigh 185 lbs atm and got properly bounced around, will have to repeat this a few times before i declare it " tough " .. but it's certainly not flimsy,.,..

So, after all that disaster, it's a running machine ! and ready for upgrades !

[Doctorbass]

Nice!!!

So much past problem.. fun MUST begin!!!

Doc

[kevo]

It looks and sounds like major fun, glad you worked through all the issues. I'm green with envy!

[wojtek]

I could not agree more.

Drifting a trike is not only fun, it is really, really easy. You will feel like a proper rally driver in no time.

I am glad you are going with a 20 inch rear wheel. 20s are much stiffer generally and easier on the frame.

Matt

depends what you want to do i guess...

i think in the end im going to run my cobra in 2 versions..
20'' front 26'' rear with 5405 [ as Kenny could not provide 24'', but fortunately there is enough clearance for 26 vrim with big thick hookworm 26x2.5!!!!

second one will be 16'' front and 20'' moto rear wheel with 5403...

[wojtek]

what type of thottle is your preferred for trikes?

i like thumb throttle, as there are a lot of forces going on both handlebars when cornering, i rather keep my hands of firm handebar grips than throttle!

[Sacman]

Cool Gaston! Now we just need video of you fishtailing that thing.
(make sure we can see your egrin)

[JohnC]

Is your problem the wrong chain size? The plates look to long. Copied this from a bike site.

“Bicycle Chain Size
When buying a new bicycle chain, you do not really have to worry about the length of the new chain. Bike chains come in a length that is longer than needed, so you have to use a chain tool to shorten the chain to the right length.
It is important to know the bicycle chain speed or width that your mountain bike requires. Bike chains come in different speeds, generally ranging from 5 to 10 speed. The way they are different is by their width, which is usually determined by the length of the pins. The speed of the bicycle chain is simply the number of cogs on your rear cassette. For example, if you have 8 cogs on your cassette, you would need an 8 speed mountain bike chain.
Often, the width of 6, 7, and 8 speed bicycle chains are similar enough to be interchangeable. 9 speed chains are narrower, and 10 speed are narrower yet”.

Put up a video of your machine in action Shrub.

[Ypedal]

Thumb throttle, yes, as discussed by Knoxie this is pretty much the only way to fly with these side steer type controls..

Fishtailing will require a bit more power, right now it just " grabs " and i've had one of the front wheels way up in the air near tipping point lol... ( and yes.. i was leaning far over.. )

To pull a proper donut required enough power to break the tire loose and spin fast in relation to vehicle speed.... i'll get there !.. have faith !

[Ypedal]

The original 24" rear wheel had 8 speed cassette, so the inner links of the chain are thin, see calipper numbers above..

My next step is to remove the rear shifter and lock the derailler in place with a short cable, this will free up valuable space on the bars..