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by johnrobholmes
Oct 11 2018 11:50am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Alta Motors Redshift
Replies: 67
Views: 2375

Re: Alta Motors Redshift

Excellent observations, thank you for sharing. Sounds like I would be a map2 sort of rider. I'm considering one of them now :lol:


How loud is the electronic switching noise compared to the Sur Ron? Chain noise?
by johnrobholmes
Sep 04 2018 4:53pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

I put the 58t rear sprocket on my bike with the stock rear wheel. Same story other people have, it has great low end but feels gutless past 15mph since there isn't enough load now. The 17" wheel with the 48t was perfect. I think between 55 and 52t would be a much better spot for the stock system. O...
by johnrobholmes
Aug 31 2018 10:21am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

I put the 58t rear sprocket on my bike with the stock rear wheel. Same story other people have, it has great low end but feels gutless past 15mph since there isn't enough load now. The 17" wheel with the 48t was perfect. I think between 55 and 52t would be a much better spot for the stock system. Or...
by johnrobholmes
Aug 04 2018 2:22pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

I got sick of the first gen air shock needing constant work.

by johnrobholmes
Aug 03 2018 7:20pm
Forum: E-Bike Technical
Topic: The wheel-building spoke-lacing thread, post your tips
Replies: 231
Views: 33145

Re: The wheel-building spoke-lacing thread, post your tips

Doesn’t really matter unless the rim is so deep that you need longer nipples to reach down to the eyelets during assembly.
by johnrobholmes
Jun 16 2018 7:32pm
Forum: E-Bike General Discussion
Topic: Why are more of you DIYers not in the e-bike business?
Replies: 127
Views: 7080

Re: Why are more of you DIYers not in the e-bike business?

I wasn't just flipping cheap goods for triple the price of online though, that is a game that anybody could have done. Quality controllers, quality batteries, and handbuilt wheels that wouldn't immediately start breaking spokes. We were simply trying to sell quality kits and bikes instead of the che...
by johnrobholmes
Jun 15 2018 2:24am
Forum: E-Bike General Discussion
Topic: Why are more of you DIYers not in the e-bike business?
Replies: 127
Views: 7080

Re: Why are more of you DIYers not in the e-bike business?

I think others have put it into good terms on why not to get into the ebike business. Here is my reason why I got out. People want you to make all the decisions, do all the leg work, tell them what to do to build a bike. Then they buy $30 in spokes after taking a few hours in time. Hey, you do reali...
by johnrobholmes
Jun 11 2018 10:34pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

I did a 5 month review. Probably nothing new to yall here, so I kinda forgot to post it. I'm feeling about the same today, loving to ride it a lot.

by johnrobholmes
Jun 01 2018 8:17pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

Re: FOC identification

It is potted so I can't really get into it without destruction. I have asked the company to reference the type and position of current sensors if they would like to give me some information to go on.
by johnrobholmes
May 31 2018 11:09pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

Re: FOC identification

A hobbywing unit. It is only compatible with their motors and offers no tuning of motor parameter, so it's quite limited in this regard.
by johnrobholmes
May 31 2018 4:35pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

Re: FOC identification

I differenced two phases without the filter and it’s a square wave. Ground on the negative terminal, probes on the phases.
by johnrobholmes
May 31 2018 4:04pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

Re: FOC identification

They are running a 14khz AC waveform on all three phases, like a stepper driver. Seems to cause currents on the RC filter, smoked the first set :lol: . The bits I have to build a 1k LPF are 10ohm resistors and 10uf caps, I'll need some different values to tamp down the currents I suppose.
by johnrobholmes
May 31 2018 3:03pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

Re: FOC identification

a zoomed in look at the switching at 50% throttle. Very linear rise and fall to duty cycle, with very large portions spent at 0 and full duty. Curious.
by johnrobholmes
May 31 2018 3:02pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 409

FOC identification

I've been having some lively discussions over a new controller in the RC realm that is claiming closed loop FOC. By all accounts, I can't make it fit what I know to be FOC. Mainly, when looking at the voltage from the controller, it is quite trapezoidal in shape. The area under the curve has a linea...
by johnrobholmes
May 28 2018 1:39pm
Forum: E-Bike Technical
Topic: 2WD (dual motor, two wheel drive) Trike build.
Replies: 170
Views: 31211

Re: 2WD (dual motor, two wheel drive) Trike build.

The radial / single cross relace still holding up?
by johnrobholmes
May 24 2018 3:27pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

liveforphysics wrote:
May 24 2018 1:57pm


We are sitting on the cusp of motorcycles and cars both all making the transition to EV, and the world will never look back.
I sure hope so. My city is just over 100k people and the main strip gets downright oppressive from exhaust fumes when the air gets hot and stagnant.
by johnrobholmes
May 22 2018 3:56pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

liveforphysics wrote:
May 22 2018 9:35am
Peak power output for any battery happens when Vsag is 50%.


Interesting to know. Peak power on a PM motor tends to be near 50% of unloaded RPM too, if I recall correctly.
by johnrobholmes
May 20 2018 2:56pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

I’ll be waiting patiently for when y’all release a tuned version. Already have a spare battery on order for having one “beat on it” pack and one long life pack.

Does the asi support two operating modes? My only concern is that I won’t be able to hand my bike off for test rides once I hot rod it.
by johnrobholmes
May 20 2018 2:23pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

The difference between 45mph stock and 70mph with the asi being mostly field weakening?
by johnrobholmes
May 18 2018 7:07am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

macribs wrote:
May 17 2018 3:39pm
Man I missed the bobber bike. Thats a good looking one as well.

Image
This is the seat I want to build for mine.
by johnrobholmes
May 18 2018 7:07am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

Probably needs to be charged. Charge it up before you go on joy rides.
by johnrobholmes
May 11 2018 10:27am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

There is 4" of room at full compression with the 17" wheelset, so there should be 2.5" of room with the standard wheelset. This is straight above the tire at the rear of the seat. Closer to the front there is a lot more room since the wheel is round.
by johnrobholmes
May 11 2018 8:03am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

yeah, that rear assembly looks terrible. Ruins the look of the bike. Wonder how many minutes on a bumpy road would break the mount or the swingarm eyelets.
by johnrobholmes
May 10 2018 10:15pm
Forum: E-Bike Technical
Topic: Cop proof throttle
Replies: 32
Views: 1795

Re: Cop proof throttle

If I had to do something stealth, I'd go the hall route. Glue/sew/epoxy a magnet inside some "special riding" glove(s) in between the web of your finger & thumb, glue a hall sensor inside a dummy grip shifter. The shifter is a good excuse to have what looks like a cable or hose coming out of it, yo...
by johnrobholmes
May 09 2018 6:32pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 2713
Views: 158276

Re: Sur-Ron - New Mid drive Bike

Using a nice charger, ahhhhhhhh! It’s nice getting some data on recharge amp hours and what voltage the pack is. I just yanked the connector from the semi-damaged stock charger whilst waiting for the replacement from Luna. At 5 amps the satiator gets rather hot, so I turned it down to 4 amps. As lon...