20 inch full suspension street build (now with twin motors)

[cwah]

you should definitely pitch doc!!

 

[nutnspecial]

That being said, there is no way of knowing what bike would be quickest without pitting them against each other.

O yeah, that would be pretty awesome. I'd have to imagine we demand a performance from LFP also

 

[cwah]

Matt,

As usual, your build are awesome and inspiring.

As for Delta Wye switching. I have run a Delta Wye switch, using just a manual switch on my mountain bike that has your V1 Drive on it. I love it. 2 reasons, 1 is that it makes it easier on the controllers and motors if you are doing slower speeds, and 2 the increased throttle control at lower speeds doing single track riding where control is extremely important.

Any info on the "other" controllers you are testing out?

Geeze, I have no idea....

I would say that the problem with his setup is two wheel drive becomes useless when the front gets light. All of the power my bike makes is delivered to the rear wheel. So, I can actually put that power to the ground. That being said, there is no way of knowing what bike would be quickest without pitting them against each other.

Matt

I've seen your video and... I wouldn't be so sure. I'd say with all this power on 1 wheel it will tend to wheelie very strongly so you can never really accelerate to the maximum. But a 2 wheel drive you have better traction (so you spread the force) and the front wheel is actually pushing the bike down!

Most of the time 2WD have better start than 1WD, so I wouldn't be surprise by a better acceleration for the same power.

 

[macribs]

Oh man the ultimate e-bike stand off. How cool would that be?
Two dual motored e-bikes racing on the drag strip. Both pushing the limits within their choice of motors.
That would be insane to watch - heck I'd pay to see a live stream.

 

[recumpence]

Matt,

As usual, your build are awesome and inspiring.

As for Delta Wye switching. I have run a Delta Wye switch, using just a manual switch on my mountain bike that has your V1 Drive on it. I love it. 2 reasons, 1 is that it makes it easier on the controllers and motors if you are doing slower speeds, and 2 the increased throttle control at lower speeds doing single track riding where control is extremely important.

Any info on the "other" controllers you are testing out?

Geeze, I have no idea....

I would say that the problem with his setup is two wheel drive becomes useless when the front gets light. All of the power my bike makes is delivered to the rear wheel. So, I can actually put that power to the ground. That being said, there is no way of knowing what bike would be quickest without pitting them against each other.

Matt

I've seen your video and... I wouldn't be so sure. I'd say with all this power on 1 wheel it will tend to wheelie very strongly so you can never really accelerate to the maximum. But a 2 wheel drive you have better traction (so you spread the force) and the front wheel is actually pushing the bike down!

Most of the time 2WD have better start than 1WD, so I wouldn't be surprise by a better acceleration for the same power.

You are very mistaken. The front wheel will not pull the front end down. The front wheel will give the same rearward rotational force as the rear wheel.

His bike will have more weight up front than mine along with a longer wheelbase. So, I would be prone to wheelies more than him. Then again, my bike is very light. That light weight could help or hinder. It is hard to say.

Luke is in a league of his own. I think I am around 60% of his power to weight ratio. He would kill me for sure.

Matt

 

[Ohbse]

Drag races are usually won or lost in the first 40 meters, if Matt's machine can leave the line cleanly at the limits of its geometry (hovering the front wheel) it has a good shot at the win unless there's a absolutely huge difference in top speed. Doc's machine might have an advantage in the middle of the run but unlikely to out launch - 2wd is no advantage at all (and probably very scary) when you're geometry limited and pulling a wheelie. I'm not familiar enough with how the Adaptto controller deals with speed differential between the two controllers, but if you end up putting down the front wheel spinning at 120km/h with the bike only going 30km/h you're probably gonna have a bad time. It's not a situation many people on earth would have experienced!

As I pointed out to Doc some time ago, it's possible to calculate exactly how much wheel torque (and hence power) you can put to the ground if you can measure the complete weight and centre of mass of the bike with you on it. This can be used to much more accurately model acceleration and will pretty precisely deliver a best possible ET. Things are slightly more complex in the real world of course, but you're certainly not going to go *quicker* than the physics allows. How much slower you end up going is down to quirks of the specific bike, skills/balls of the riders and the ambient conditions. 2wd may be awesome and a big advantage in many circumstances (I don't know first hand) but I can state for sure that it's not the best for drag racing.

Doc doesn't really want to build the best drag racing bike, he wants to build a super unique 2wd beast. Totally awesome and something to be encouraged, but it's not a recipe for quick 1/4's If you want to go proper quick then emulate the man that's already done it! Lukes bike is long, low, not particularly lightweight and leaves the line HARD.

 

[drewjet]

Any info on the new controller?

 

[recumpence]

Drag races are usually won or lost in the first 40 meters, if Matt's machine can leave the line cleanly at the limits of its geometry (hovering the front wheel) it has a good shot at the win unless there's a absolutely huge difference in top speed. Doc's machine might have an advantage in the middle of the run but unlikely to out launch - 2wd is no advantage at all (and probably very scary) when you're geometry limited and pulling a wheelie. I'm not familiar enough with how the Adaptto controller deals with speed differential between the two controllers, but if you end up putting down the front wheel spinning at 120km/h with the bike only going 30km/h you're probably gonna have a bad time. It's not a situation many people on earth would have experienced!

As I pointed out to Doc some time ago, it's possible to calculate exactly how much wheel torque (and hence power) you can put to the ground if you can measure the complete weight and centre of mass of the bike with you on it. This can be used to much more accurately model acceleration and will pretty precisely deliver a best possible ET. Things are slightly more complex in the real world of course, but you're certainly not going to go *quicker* than the physics allows. How much slower you end up going is down to quirks of the specific bike, skills/balls of the riders and the ambient conditions. 2wd may be awesome and a big advantage in many circumstances (I don't know first hand) but I can state for sure that it's not the best for drag racing.

Doc doesn't really want to build the best drag racing bike, he wants to build a super unique 2wd beast. Totally awesome and something to be encouraged, but it's not a recipe for quick 1/4's If you want to go proper quick then emulate the man that's already done it! Lukes bike is long, low, not particularly lightweight and leaves the line HARD.

I totally agree.

Matt

 

[dequinox]

Yeah Luke's bike is, for lack of a better phrase, "f%$#ing scary", and that's my impression just from watching the videos.

Matt- Any idea what to expect for Wh/mi? I'm always interested to see what my fellow chain-drivers are getting...

 

[recumpence]

Yeah Luke's bike is, for lack of a better phrase, "f%$#ing scary", and that's my impression just from watching the videos.

Matt- Any idea what to expect for Wh/mi? I'm always interested to see what my fellow chain-drivers are getting...

I average 33wh per mile for most of my riding.

Matt

 

[dequinox]

Yeah Luke's bike is, for lack of a better phrase, "f%$#ing scary", and that's my impression just from watching the videos.

Matt- Any idea what to expect for Wh/mi? I'm always interested to see what my fellow chain-drivers are getting...

I average 33wh per mile for most of my riding.

Matt

That's not half-bad for two motors! My single brushed pulls that much on average... time to look at a brushless setup I suppose, especially since my (aluminum) frame is cracked. :?

Since the turnigy orange can disappeared, and I can't afford astroflight (wife would kill me), I'm thinking it'll probably be something with an SK3, or maybe a pair of them.

 

[recumpence]

I am glad for my WH per mile. I agree it is quite good for twin motors, especially considering that is an overall average for my normal riding. In that I pull a few wheelies, rip up to nearly 50mph, but then cruise alot at 25mph. It is an overall average, not an ultimate efficiency weenie total trying to eek out every last watt. :wink:

So, I FINALLY setup a CA for this thing. I have waited because of the various difficulties of setting one up on a high power system like this. It took my entire day to wire and program it. I spent a bit of time on the phone with E-bikes.ca trouble shooting it. But, I finally have it running acceptably and I am thrilled with the results!

Bear in mind, the bike has been just fine to ride with my normal PWM "Plug and play" throttle. However, I wanted to gear the bike a bit taller. However, I am already pulling peaks of 660 amps with it geared for 47mph. When I geared it up to 55mph, the controllers would over-amp and shut down. So, I have been stuck with this gearing as my maximum. With the CA, I have current limiting. This allows me to gear the bike up taller without over-amping it.

I am, also, using the three position switch for three modes. This is awesome. Mode 3 is maximum current. Mode 2 is 50% of maximum current. And mode 1 in 25% of maximum current. Right now I have it set for 400 amps (mode 3). This is great for controlled wheelies with the current gearing. If I set it to mode 2, the bike accelerates hard, but very controllably without wheelying. Mode 1 gives a pleasant smooth ride without any drama, while still eventually hitting the top speed.

Also, I still have my Delta/Wye switching. So, now I can set the Delta/Wye for whatever maximum speed I am looking for, and the 3 mode switch for the power level I am looing for. It is a wonderful setup! For instance, mode 1 in Wye would be perfect to allow a teenager to ride. Mode 3 in Wye is great for a somewhat experenced rider who is OK with alot of torque but does not want to go super fast (top speed). Then in Delta, if set at mode 1, the bike is gentle to ride, but will eventually reach a much higher top speed. It is wonderful!

I will give more results as I have them. I am still refining the programming and I have to make a handlebar mount for the CA display.

Matt

 

[DanGT86]

Glad to see you got the CA to get along with it. I can't imagine my 2500 watt bike without my CA3. Your eleventy billion watt bike had to be a handful. I wonder if you could use the PAS settings in the CA or the aux input with a gyro sensor to make a wheelie launch control for the throttle. I know you already ventured into this realm with the 1 wheel bike project but it seems like the ease of tinkering through the CA would help. It's neat to watch this project evolve.

 

[recumpence]

It is really a wonderful item (the CA).

At this point, I think I am going to bypass my Delta/Wye relays. I think I am having some issues with the relays not liking partial throttle in Delta for long durations. In those situations, the CA gets confused and the controllers shut down. I think I am seeing a funky back EMF problem related to the leafs in the relays. I am also having an issue with one of my controllers (lots of heavy abuse on that poor little controller). So, tomorrow I am replacing one controller and bypassing the relays to leave it in Delta. I will, then, relay on the CA three position switch to limit the bike for general riding versus hard blasts.

I will let you know how it goes.

Matt

 

[liveforphysics]

If you want a bench mark that is easy to compare, find an 1/8th mile flat stretch and see if you can exceed 108mph in that 1/8th mile from a standing stop.

If you do, then I will be more inspired to finish the 2x power increase version.

Nice build as usual!

ATB,
-Luke

 

[recumpence]

I bow to you, oh master of the truly insane.

At this point I am pushing for more of a "Tesla" form of ebike meaning lots of power without being too violent and untamed. The CA has provided just that. The bike is wonderfully powerful without being crazy violent.

Matt

 

[ErnestoA]

If you set up the throttle voltage threshold on the CA just slightly below the resting throttle voltage, the motors will always spin once low speed throttle cut point is surpassef. This keeps the slack out of the chain which smooths out that first little jolt when you give it throttle and it also keeps the freewheel from clicking when you're pedaling. It only pulls an amp to keep things spinning and once you slow down past the min speed setting, the throttle signal will cut.

Doing this made my bike a whole different animal. The low speed control and smoothness was an awesome change from the violent wheelie popping!

 

[recumpence]

OK, LOTS and LOTS of time spent on this bike over the holiday weekend.....

Here is where I stand;

I eliminated the Delta/Wye relays because I had a problem with them related to continuous current handling. Basically I was exceeding their current handling and actually blew a controller because of it. So, I went to Delta only. That was fine except the controllers run hot in Delta and the motors pull a HUGE amount of power in Delta. However, Wye is too slow. So, I decided to gear it up in Wye and see how it runs. So far so good! I have it geared for a bit over 30mph in wye and it is running wonderfully. It has, however, lost its insane "Scare the life out of you" hit. That is fine. It still wheelies strong and it is running sooo smooth now! Tomorrow I am gearing it up further (around 41 or 42mph) in Wye and I will see how it runs. I can tell you that the motors and controllers are running must cooler now and the CA is behaving much better with it in Wye.

My prediction of how it will run geared for 40mph in Wye?

I think it will pull strong from down low and lose some of the top end power it had. I think it will have pleasant characteristics and be plenty strong without being such a nightmare to handle.

Ultimately I would love to order some motors with a higher KV in Wye and find the happy medium between the truly insane it used to be and the strong, but relaxed machine it is now. But, again, this depends on how it runs geared up taller.

Oh, also, it has a more muffled sound now. At 12,000 RPM the motors were quiet, but high pitched.

Matt

 

[recumpence]

Hey Guys,

I have ALOT to report.

First, I have been having an issue with the CA. I have been cautious to implement the CA because of the relative complexity of using it with very high power RC systems. However, at this point, I have it setup and running fantastic!

I went to Wye as mentioned earlier partly because of a current overshoot issue I was having with the CA. Bascially when throttling hard the CA would overshoot the output for a fraction of a second before finding the correct point to regulate the power. It did not happen every time I hit the throttle. But, it was often enough that it was unsettling. Basically, throttling hard could result in smooth response at the set current limit point, or it could result in a hard wheelie while the CA tries to get the current limit regulated properly. After many emails back and forth with Justin, I have it running nealy perfect.... FINALLY!

Here is the situation;

Basically it boils down to throttle response of the controllers versus the throttle response of the CA. I had a throttle ramp (delay) programmed into the controllers. So, the throttle delay in the CA was battling with the delay in the controllers resulting in an occasional overshoot of the current limiting. Once speeding up the ramp rate in the controllers the current overshoot completely vanished!

Then I went back to Delta for higher performance (geared for 45mph top speed) and went back to my controller and CA programming research.

The next issue I had was controller erroring due to overcurrent. I tried seemingly everything to compensate for this. The controllers were seeing a very short (a few millisecond) burst of high current when hitting the throttle hard in high current mode. I tried setting the current limit lower in the CA and I had to turn it way down to eliminate the controller erroring. I had to set it down at 10,000 watts (on an otherwise 28,000 watt system) to prevent errors in the controllers. This is unacceptable. The final solution I came up with was slowing the CA ramp rate a bit lower than I had it. The perfect ramp rate is .50 MS pulse rate increase per second of time. This means the system takes a full two seconds to ramp from zero to full throttle. This ramp rate eliminates the current overage in the controllers without affecting the throttle "Feel".

The bike is running like a Tesla. It pulls nice and STRONG without being violent. The violent response it used to have was fun at times. But, honestly, it is a bit of a nightmare in day to day cruising. This setup is awesome. I can wheelie if I want to, but it does not wheelie unexpectedly. I normally have the multi-position current switch in the middle setting for 50% current (around 10,000 watts peak). This gives nice accelleration with awesome control and very smooth feeling. Once in a while I click it to full. This gives a very powerful rush of speed without wheelying unless I really want it to.

I am very happy at this point.

Matt

 

[drewjet]

Very cool Matt. Glad to hear you have it dialed in. Still would like to know what Speed controllers you are using

 

[recumpence]

I am still running the Edge 160 controllers.

Matt

 

[DanGT86]

Doesn't the CA allow you to adjust the gain/response time to overcurrent to make it limit sooner without you having to slow the whole throttle ramp? I'm sure 2 seconds to full power is still insane on a bike like that but it seems like slowing the ramp overall may be addressing a symptom rather than the root problem of slow limiting response. Hate to see you sacrifice throttle response everywhere just to address a few spots where it would overcurrent.

On second thought the CA would just pull back the throttle ramp under limiting anyway so maybe you just manually found the sweet spot instead of it doing it for you. Idk, just thinking out loud not trying to be critical.

 

[rodgah]

ha, I have the same issue with it overshooting randomly, even set for something silly like 30A it will still pull like a train for a split second sometimes. Though mine is a BETA version of the RC-CA, I have fiddled with it endlessly to try and solve it.....but never looked at the ESC settings :lol: . I will give that a try. One thing that annoyed me about adjusting ramp rates is that if you have a dead zone at the start of your throttle, it will ramp through that dead zone.....so causing a weird unresponsive feeling. I know you can set the CA to take out the dead zone but......magura throttles rarely return to the exact same resistance at idle (well at least the 4 that I own) so you have to factor in a bit of a dead zone.

 

[recumpence]

I found the odd throttle response problem....... Justin and I have been going back and forth on it. What I did was speed up the throttle response in the controllers and slowed down the response in the CA. This eliminated the split second throttle overshoot. The CA regulated current wonderfully consistant now.

I need to move to a bigger shunt, however. The 200 amp shunt I have is confusing the CA at the 600 amps I am regularly pulling through it.

Matt

 

[recumpence]

Hey Guys,

I am having so much fun with this bike, that I have decided to build a new drive unit for it!

So, I have this drive unit (or the motors separately) for sale on this thread https://endless-sphere.com/forums/viewtopic.php?f=9&t=72926

The new drive will be a radical system. I am not saying what it will consist of. But, once these motors (or whole drive) sells, I will begin ordering everything I need to start building the new system.

Matt