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

[Gab]

awesome build !

Being sensorless and mid drive do you have any motor stutter issues if you chose the wrong gear and go very high load and low rpm at starts ?

 

[macribs]

He runs a left chain drive to a single rear sprocket. As he runs dual motor he got insane amount of power a relatively low gearing so I doubt he would ever be in a stall situation.

 

[recumpence]

awesome build !

Being sensorless and mid drive do you have any motor stutter issues if you chose the wrong gear and go very high load and low rpm at starts ?

High load low RPM is always an issue. But, with twin motors it is not a problem.

 

[recumpence]

I've been riding the bike quite a bit and I think I will gear it down for 45mph top speed. 54 is just too fast. Also, I want to reduce the amp draw a touch. So, dropping the gearing will reduce my top speed, reduce the amp draw a bit, and give better snap for wheelies.

Matt

 

[Warren]

45 mph is the speed I like to drive my car at. So yeah, I think it should be plenty for a bicycle.

 

[spinningmagnets]

If I had ordered a custom build and could choose either a higher top-speed, or...better acceleration that tops out at 45-MPH? For me, 45-MPH is the most I'd recommend.

I'm not a big wheelie fan, but brutal 0-45 acceleration is an extreme roller-coaster with no lines to wait in...and that's something that enthusiasts will pay big money for. Its addictive fun to embarrass gasser cars and motorcycles from stoplight to stoplight...

 

[recumpence]

Ok, I'm lovin this thing. 45 mph gearing is awesome. The controllers are far happier, the bike is more fun to ride, and everything is running cooler.

I did some range testing. Under race conditions (super hard throttle at every corner exit, riding as hard as I can) the bike is good for 18 to 20 miles of range. At 45mph the range is 32 miles. In wye at 25mph, it is good for over 60 miles. That is 23wh per mile. Pretty darn good for a twin.

Matt

 

[John Bozi]

We all love seeing the inner workings of a vehicle and how it was made even, but at the end of the day when everything is set to how it will be. You don't drive cars without a bonnet for example right?

2 cents of subjective taste, less is more. Just a couple of light side covers might funnel air through too?

 

[recumpence]

Yuck....

There is a reason "Naked" motorcycles are so popular.

I agree, taste is an individual thing. That look would be far too boring. The point to this bike is to be hard edged, not soft and compliant. It is a top fueler, not a Camry. :wink:

Matt

 

[Stielz]

I'm really impressed with how much current those little ESCs can take! you mentioned it was pulling 600A during acceleration, how many seconds would it be pulling that much current for?

 

[recumpence]

I'm really impressed with how much current those little ESCs can take! you mentioned it was pulling 600A during acceleration, how many seconds would it be pulling that much current for?

331 per controller for 1 second and 280 amps per controller for 1 second.

Remember, that is so much power the front wheel is of the ground much of the time. So, it is short bursts.

Matt

 

[Grinhill]

Awesome work as usual!

Sorry if you already mentioned it, but what did your wheelbase measurement end up at?

 

[recumpence]

Awesome work as usual!

Sorry if you already mentioned it, but what did your wheelbase measurement end up at?

43.5 inches

It looks like an even 40 miles of range in mixed riding. This bike is crazy how the range differs depending on riding style. With this much power, the range can really change if I get on it a lot.

Matt

 

[giblet]

We all love seeing the inner workings of a vehicle and how it was made even, but at the end of the day when everything is set to how it will be. You don't drive cars without a bonnet for example right?

2 cents of subjective taste, less is more. Just a couple of light side covers might funnel air through too?

Yuck agreed!

Don't give up your day job, unless your day job is designing fairing for e-bikes

Looks way better raw.

Also - recumbence - do you do builds for people?

 

[recumpence]

We all love seeing the inner workings of a vehicle and how it was made even, but at the end of the day when everything is set to how it will be. You don't drive cars without a bonnet for example right?

2 cents of subjective taste, less is more. Just a couple of light side covers might funnel air through too?

Also - recumbence - do you do builds for people?

On occasion. I have done 7 or 8 builds if I remember correctly. My builds are costly, though, due to the high performance nature of them.

Matt

 

[recumpence]

http://youtu.be/Ba06ZN-lRLg



Matt

 

[Warren]

Not "deathbike" but just watching scared the hell out of me.

 

[Byte]

Nice! More, more, more please

 

[litespeed]

Wow, that looked fast.

Tom

 

[macribs]

Wow I will start saving right away cos I need that much power too

 

[MitchJi]

[youtube]Ba06ZN-lRLg [/youtube]

 

[MitchJi]

Hi,

I cannot believe how well all of my projects have worked out lately. Everything just works right the first time.

"experience"...it makes all the difference.

"talent"...it makes all the difference.

 

[recumpence]

I'm finally getting really used to the power. It feels good not being startled every time I hit the throttle.

So far so good. The only issue I have had so far is a loose flange on one of the motor pulleys.

Matt

 

[StinkyGoalieGuy]

Matt, when you originally cut the tubes on this frame and welded on the plates to build the battery box, how did you square off the ends of the tube? I assume it never left the frame jig. How critical is this "squareness"?

 

[recumpence]

Matt, when you originally cut the tubes on this frame and welded on the plates to build the battery box, how did you square off the ends of the tube? I assume it never left the frame jig. How critical is this "squareness"?

I used a grinder with a flap disc. I tried to make all tubes and plates as tight as possible. I would say 2mm gap is the largest gap I had to fill.

Tight gaps and clean material makes TIG welding so much easier and stronger.

Matt