KMX trike build (updated pics)(new HD video)

[migueralliart]

It gets better, I felt the same way at first but now I feel very comfortable with the steering. Don't forget to check the amount of toe-in. When I had mine set with too much, it handled weird, was less efficient and wore out my tires.

Yes i adjusted the toe. I'm wondering if the camber is adjustable on these trikes?

 

[chvidgov.bc.ca]

It's interesting how the handling differs quite a bit between different trikes. I find my Catrike has a lot more brake steer when using one front brake only, with the trike tending to "dive" toward the side of the brake, than on my Actionbent which is very close to no brake steer. Another issue is pedal steer, which makes the rear end waggle on each stroke of the pedal. On both trikes using a lower cadence/higher gearing delivers less pedal steer. The Actionbent is a 26/20/20 trike whereas the Catrike Road is a 20/20/20. I also found that using the larger Big Apples led to undesired shimmy in my Actionbent, compared to using Maxxis Hookworms, on the front. Lower inflation was problematic compared to higher inflation. There are a lot of variables...brake steer, pedal steer, tire characteristics and inflation, toe-in, camber, Ackermann etc, and it may take a while to find the sweet spot in your handling. It can also help to put the tie rod below the attachment point to the kingpin, instead of above it. Even 1/16 inch toe-in difference is noticeable in affecting the handling. The larger Actionbent definitely feels like a Cadillac compared to the Catrike.

 

[migueralliart]

Some updates

Installed the shifter for the rear derailleur. Bought an SRAM grip shifter and cut a wuxing handlebar grip. 7 speeds it is. Now I need to tension the rear chain a bit since it is a bit loose. It still shifts good but i'D like to tension it a bit.

Shifter and Brake

Installed a CA up front and used all the cable routing stops for the front derailleur that I won't have.

CA with a bit of clearance on the right

Left clearance

Now onto the throttle ... I bought a throttle from an user here on ES a while ago. Now I got it installed YPEDAL's style. Definitely the best way to install a throttle on these KMX trikes.

 

[waynebergman]

Nice looking project Migueralliart.

I am also wanting to build a tadpole for my next project. I have only rode a Catrike once and loved it so I have bought the plans from Atomic Zombie for the Warrior tadpole and will give the home built version of this a try sometime in the new year. I have also an HS3540 that is set aside for this project that I will run 48v 35 amps with it. I am looking forward to watching your progress and wish you could luck.

 

[migueralliart]

Well I did my first test ride today.

So far it is running with a lyen mini monster controller setup for 35amps and 12s lipo. Lyen added a shunt and modded it for more amps.

After several full throttle launches the controller gets warm to the touch. I had a plastic enclosure box which I modified to attach to the rear part of the seat. This is a temp solution until I make a permanent box.

Now some thoughts on the setup;

I love the hs3540 on a 20" rim at 35 amps it is brisk and agile I can't imagine it at 60 amps.

Top speed using the 120% setting is about 27mph. I'll have to ride the trike for a while before commuting since the steering at 27mph is a bit scary.

The CA DP is a perfect addition to this setup.

Brakes lock on the right under hard braking so I might have to adjust them.

Anyway I've attached a picture. Will start taking some more during the week.

 

[migueralliart]

A little cable management goes a loooong way. It is nice to ride this thing. It definitely gets a loot of attention. Working on the battery enclosure for now so I am still running it with a small lipo pack.

 

[Marc S.]

From driving this thing around all I can say is the steering takes some time to get used to. It is totally true that when hard cornering even at low speeds you can turn over. I will definitely take my time to learn how to control this thing.

I never rode a KMX but have 7500km on an ICE Sprint under my belt.
Take it easy on the corners in the beginning. Find a quiet spot like a parking lot and do some training. Don't forget to lean to the front and into the corner with your body if you corner fast. Train some hard braking as well. You will need it.
After some practice you'd be amaized how fast these trikes corner and how little road is nessesary for a full stop from full speed.

Aah, and forget the rear brake for anything else than a park brake. Handbrake turns are fun with a car but the single best thing you can do to rollover a trike. Works nearly every time (as I found out)

 

[migueralliart]

Hey thanks for the recommendation.. there I was just cornering and sitting back. I'm gonna do some practice now.

BTW hard braking this thing on a straight line rocks. The BB7's are awesome. So far I don't have a rear brake and I intend to keep it that way. Instead I do regen with the motor so it stops pretty good.

 

[Marc S.]

Hey thanks for the recommendation.. there I was just cornering and sitting back. I'm gonna do some practice now.

BTW hard braking this thing on a straight line rocks. The BB7's are awesome. So far I don't have a rear brake and I intend to keep it that way. Instead I do regen with the motor so it stops pretty good.

Yeah braking power of a tadpole trike is great. I've got 'only' 70mm drum brakes at the front but there is nothing lacking in the stopping department here.

An other thing about the 'scary' steering:
Don't use a hard grip on the handles at high speed! It's not a bicycle! If you use a firm grip every body movement will be transfered to the steering making it rather twitchy.
Just guide your handles with your fingertips. It may help as well at high speed if you gently push the opposite side handle to guide the trike through road bents (push left to turn right and vis versa) than pulling at the side you wanna go. Keep the pulling business for hard cornering.

Somehow I managed to dampen my steering with sticky, high quality, water-resistant grease in the headset bearings. I don't know if the old grease reacted with the new one making it stiffer since it took some weeks till I noticed.

A rear brake to secure the trike from rolling away is mighty handy. Especially if you get up from your trike on a grade. Few things feel more stupid than chasing your trike down a hill. I just noticed when I swopped my 26" rear wheel for a 24" rear and lost my cantilever park brake in the process.

 

[Ypedal]

Few things feel more stupid than chasing your trike down a hill.

lol... true.. specially with a trailer and your dog in it !

make sure both your front brakes are adjusted equally, get on soft dirt and do slow hard brakes to see wich one is grabbing first, this a big deal when in traffic at high speed and a panic stop comes up.

rear wheel regen is awsome on these things. great way to throw the rear wheel into a drift !

 

[migueralliart]

Well thanks for all the suggestions. I got to do some more practicing on hard cornering leaning towards the curve definitely helps a LOT. Tweaked the brakes and now they are even. My rear torque arm is now useless since it seems the DP420 came loose. I notice the epoxy pack was expired but I'm not gonna try to use it again. Instead I'm going to fabricate a torque arm using both the caliper mounts probably 3/8" thick.

Lyen's mini monster controller is pretty good so far doing 30-50 amps on this and it doesn't get crazy warm but just warm to the touch which is good for me.

BTW when you guys use the ebikes.ca simulator do you use semi recumbent or full recumbent?

The reason I ask is because yesterday I got ~9.5 miles of trip distance and my 12S1P pack was at 3.80v/cell. I'm using turnigy 6s 5Ah. According to the simulator using semi recumbent I should get ~10 miles.

 

[Marc S.]

BTW when you guys use the ebikes.ca simulator do you use semi recumbent or full recumbent?

The reason I ask is because yesterday I got ~9.5 miles of trip distance and my 12S1P pack was at 3.80v/cell. I'm using turnigy 6s 5Ah. According to the simulator using semi recumbent I should get ~10 miles.

I use semi recumbent.

If I understand correctly the range in the ebike simulator is calculated for a totally flat track at full speed without frequent braking and accelerating. Thats not how you normally use your trike on the road.
Acomplishing 9.5 miles real road out of calculated 10 miles range it pretty precise, don't you think?

There is also the little uncertenty about how much juice you really extracted out of your battery...
To increase battery life I normally charge my 5Ah RC-LiPo packs to 4.1V per cell (90% charge/4.5Ah) and treat them as 4Ah battery packs in every day use to avoid sucking them dry. In the beginning I deep discharged and killed a 6s/5Ah pack and don't like to repeat that.

If I don't made a mistake in my calculation that means my 10s3p battery (37V/15Ah nominal, 42V off the charger) is in fact a 41V/13,5Ah battery at 4.1V per cell and I suck no more than 12Ah out of it. 41V/12Ah is actually what I type in the ebike simulator to get a 'feeling' about my potentual range and top speed.
When I connect the packs to 15s2p (55V/10Ah nominal), 61,5V hot off the charger at 4.1V per cell, its a 61V/9Ah battery that gives me 8Ah of juice to play with.

 

[migueralliart]

I understand everything you explained. The thing is my CA is showing 9.5trip distance and my resting voltage is 3.8v which seems a bit too high if I take into account this is storing voltage.

I checked the shunt value and it is correct. I also checked the wheel diameter and it is ok.

I really didn't do much regen so I might do another test run using my cell phone to log distance.

Florida is all flat and the majority of the areas I commute to are flat with not that many stops so the simulator pretty much resembles what my route is.

 

[Marc S.]

Few things feel more stupid than chasing your trike down a hill.

lol... true.. specially with a trailer and your dog in it !

make sure both your front brakes are adjusted equally, get on soft dirt and do slow hard brakes to see wich one is grabbing first, this a big deal when in traffic at high speed and a panic stop comes up.

rear wheel regen is awsome on these things. great way to throw the rear wheel into a drift !

You have to train your dog to stop the trike and bring it back then!

I'd love to try out regen braking but I've got a Bafang BPM in my Sprint. The upside is, even with a 24" wheel, 10s battery and 35A controller it climbs like a chamois without breaking a sweat. Even in 26" wheel it's no slouch.

 

[Marc S.]

I understand everything you explained. The thing is my CA is showing 9.5trip distance and my resting voltage is 3.8v which seems a bit too high if I take into account this is storing voltage.

I checked the shunt value and it is correct. I also checked the wheel diameter and it is ok.

I really didn't do much regen so I might do another test run using my cell phone to log distance.

Florida is all flat and the majority of the areas I commute to are flat with not that many stops so the simulator pretty much resembles what my route is.

Then try 'full recumbent' in the simulator. I live in pretty flat northern Germany and even without rigurous testing had the feeling that the range of my Sprint is somewhere between the 'semi recumbent' and 'full recumbent' calculations. If you pedal a lot you can extend your range quite dramaticly as well.

Riding in a crowded city with lots of stop and go most of the time, getting a new motor/controller, switching from 20" to 26" to 24" rear wheel within a two month period resulting in different seat angles and wind resistance, while the temperature dropped 10-15°C in the same time as well, using 37V LiMn or 37V/60V LiPo batterys any other day, didn't made my Sprint an optimal test bed for range calculations...

 

[energyi]

Isn't the simulator for a two wheel bike, not a trike? So recumbent trike will be slightly deceiving due to the extra drag from the extra wheel. I know my trike is much slower, but much funner.

Instead of a back wheel parking brake, I use a strap on a front brake (an old leather ski strap that quickly adjusts and pulls tight). I've heard a Velcro strap can keep the trike in parking mode pulling one front brake lever and keeping it pulled. Much easier and less expensive than another cable and braking mechanism on the back wheel.

I did have an old VW square back. With the black Labrador in the back seat it started rolling towards a Colorado cliff after I parked and got out. I had to jump back into the rolling car and ram the parking break. Whew!

Best, Joe Mc.

 

[Marc S.]

Isn't the simulator for a two wheel bike, not a trike? So recumbent trike will be slightly deceiving due to the extra drag from the extra wheel. I know my trike is much slower, but much funner.

As I understand (I don't understand much about this stuff) the drag of the third wheel is less importand than the improved aerodynamics of a more reclined recumbent above a certain speed (20km/h?). From my numerous calculations in the ebike simulator (I love this thing!) and some real world results on the road my fairly low ICE Sprint fares somewhere between 'semi recumbent' and 'full recumbent'. Makes sense since my trike a full recumbent but with more drag from the wider front area and third wheel.
Anyway there is a online power calculator for different bicycles and velomobiles (unfortunatly no unfaired trike) here: http://www.hembrow.eu/personal/kreuzotter/espeed.htm

Unfortunatly all bets are off if you ride through a hilly environment or peddel with more force (or less), add pannieres, ect.
With my former setup (ICE Sprint, 3x20" wheels, Bafang 250W, 15A controller, 36V/11Ah battery) I archived real world ranges from under 60km without bags to 110km loaded with 25kg luggage.

Instead of a back wheel parking brake, I use a strap on a front brake (an old leather ski strap that quickly adjusts and pulls tight). I've heard a Velcro strap can keep the trike in parking mode pulling one front brake lever and keeping it pulled. Much easier and less expensive than another cable and braking mechanism on the back wheel.

I got some rubberband too, but if you are accustomed to use a park brake lever and getting up from your trike not worrying where it might end, the sudden lack of that park brake can lead to some surprise...

 

[migueralliart]

At last my 12s2p enclosure is ready for the daily commute. Any suggestions besides a spare tube and adjustable wrench to carry around?

 

[BATFINK]

Little multitool with Allen keys for adjusting everything from your seat, handlebars, brakes etc and a couple cable ties

Sent using Endless-Sphere Mobile app

 

[energyi]

Excellent thread, thanks again.

I bought a Slime Schrader Valve Tube, 20" X 1.75-2.125". Don't know if it works, but it is only a couple bucks more than a regular tube. Don't want to be changing a rear tire!

PLEASE tell us where you got that 12S2P enclosure box, thanks in advance. Nice location behind the seat!

Joe Mc.

 

[migueralliart]

The enclosure was bought locally from mpja.com this is the link ;
http://www.mpja.com/1043in-X-728in-X-374in-IP-65-Plastic-Project-Box/productinfo/17398+BX/


This is the tube I bought
http://www.amazon.com/gp/product/B00165U0U8/ref=oh_details_o00_s01_i00

I hope it lasts cause I don't really want a flat.

 

[migueralliart]

Little multitool with Allen keys for adjusting everything from your seat, handlebars, brakes etc and a couple cable ties

Sent using Endless-Sphere Mobile app

Thanks I forgot about the multitool.

 

[migueralliart]

Well as promised here is all the updated pics of what I think is my new commuter in combination with my idrive. Enjoy!

And RIDE STATS
NO REGEN
LOTS OF START AND GO PULLS
NO PEDALLING

 

[SamTexas]

Looks nice. So around 22wh/mi. What are the max and average speeds?

I saw RC LiPo in your battery box!?? I was expecting A123 26650 cells. What gives?

 

[ohzee]

Looks nice. So around 22wh/mi. What are the max and average speeds?

I saw RC LiPo in your battery box!?? I was expecting A123 26650 cells. What gives?

haha no shit ;p he's the man with enough a123 cells to kill elvis

Nice looking ride though and the box fit's very nice as well.

That your round house ? Looks cool.