John in CR's ebikes

[John in CR]

My first bike was a tricycle.

[John in CR]

My second bike had 2 wheels

[John in CR]

This sucks

[John in CR]

Damn,
I was almost finished with the next one.

[John in CR]

Reserved for build with monster scooter hub

[John in CR]

reserved for coast to coaster

[John in CR]

Reserved for monocoque build

[dogman]

Now you have crossed into a real quality build with that cannondale.

[vanilla ice]

So the little guy gets the freeride? Luckeeee!

[GCinDC]

Fantastic, John! I love them.

Great to have you on the podcast too! Troy just put it up here.

[John in CR]

Ebike jousting sounds like a cool sport to play against trevor.

[dingoEsride]

Very nice interesting looking builds John especially the canondale, I'm not quite sure about the small wheels but seems to be popular on here

[dogman]

I think I understand what you mean John about the frame geometry. Perhaps the seat is in the wrong place for the frame now that it's longer. Further back for the seat makes sense to me too. Perhaps some kind of custom steatpost adapter could be welded, that would exit the existing seatpost from the bottom? A tricky problem to mount a new seatpost tube with alloy frame. Too much leverage, and Crack.

Maybe some kind of mod to a steel seatpost so that the nose of the saddle would just about rest on the top of the seatpost tube. Then an additional strut could be run to the back of the seat, diagonal to the bottom of the seatpost tube?

[John in CR]

What a frocking waste of my time.

[John in CR]

hello

[John in CR]

Dogman,

On the seat extension I don't know yet where I'll end up, maybe a 2 part sleeve that goes over the existing seat tube and support tube with it somehow anchoring in the seat tube for it to take over half the weight. The easy route is to just hack the seat tube off and make an extension. Another route could be to make it a Super Double V and add 2 more seat supports that anchor at the bottom of the existing supports to support the seat extension. Decisions decisions, I just gotta avoid analysis paralysis that often afflicts me.

[dogman]

I'd be trying experiments that don't cut the frame first. Wierd custom seatpost type stuff.

[grindz145]

That cannondale is freakin wild! Thanks again for doing the podcast. Too much fun.

[John in CR]

A couple naked shots of the SuperV to give you guys a better idea of what I'm working without the zip tied controller and test run battery placement clouding the issue.

Super V left front quarter.JPG (29.74 KiB) Viewed 940 times

Super V first side shot.JPG (28.19 KiB) Viewed 936 times

[Green Machine]

I love the duct tape work on the clown bike...i was contemplating a bmx build with entire bike (as much as possible) wrapped in black duct tape. the clown bikes my favorite.

the super v is obviously beautiful...i would like to follow that build thread if there is one on it. i rode a bike recently with a hub motor like that as the mid drive...rode really nice...heck of a hill climber.

[Spacey]

I wish I had the time and workshop to build lots of experimental bikes, cheers for posting the pictures.... they look like a lot of hard work paid off.

[Hillhater]

John,
what is the advantage of mounting the hubbie in the swing arm rather than in the wheel.?
..gearing maybe ? .. but you seem to be close to 1:1 ratio ?

[John in CR]

John,
what is the advantage of mounting the hubbie in the swing arm rather than in the wheel.?
..gearing maybe ? .. but you seem to be close to 1:1 ratio ?

There are actually quite a few reasons:

The 28t at the motor 48t at the wheel reduction makes the 9C effectively running a 12" wheel so it will be able to climb anything. The lower gearing will also allow me to run the motor at 7-10kw buy going to high voltage, something not really possible without the gearing reduction. You can't just go to a higher turn count motor, because it can't handle the current. The only way is through higher rpms, just like the RC guys. It's a way for me to get the same power as my big hubs for about half the weight. The higher rpms (over 1krpm) will make the ventilation strategy even more effective, so the pretty extreme power will be relatively stress free for the motor, since 70A into a well ventilated 9x7 isn't a big deal.

Once I dial in the gearing I can have hill climbing, 40mph+, and regen braking in a light, low cost, and dependable build that doesn't sound like a cross between a drill and a vacuum cleaner.

14lbs mounted nearer the pivot point vs 24lbs in the wheel is a huge difference in terms of the suspension.

I wanted to find out first hand the noise level of a chain drive with large sprockets, and it's a non-issue. Now I have the potential for the benefits of a non-hub (changeable gearing, easy to change tire, multi-speed, etc.) without giving up any hubmotor advantages other than space savings and ease of installation.

A hub motor at high power enables a build that owns the Hanebrink as a real all terrain bike.

[spinningmagnets]

Sounds good John. I'd like to do something similar. So you have the 28T:48T chain reduction, a 9X7 hub, plus:

...What volts, what top speed, and what diameter of tire? (20" plus fat tire = 24" size?)

[John in CR]

Sounds good John. I'd like to do something similar. So you have the 28T:48T chain reduction, a 9X7 hub, plus:

...What volts, what top speed, and what diameter of tire? (20" plus fat tire = 24" size?)

The 28/48 reduction is too much with my 21.25 OD wheel. I have a 44t to swap in for the rear, which I hope clears up the off center sprocket problem, and may get to the gearing I want. I hesitate to quote speed and stuff yet, because I'm not happy yet even if sprockets were perfect. I have the pack at 30s, so only room 5s more, and the top speed is way too low. Sure I was getting close to 30mph, and don't want much faster for actual riding on this bike, but typical cruise near max speed won't cut it for me. Taking forever to get the last 5mph typical of ebikes ridden at WOT isn't acceptable to me. I want headroom, just like with every vehicle I've ever owned and almost never cruised at WOT. Boats are the only exception, but that's because water has so much more resistance.

I can't really dial in gearing and power until I move the saddle. I have to get comfortable with the ride before pushing the voltage and current higher.

FWIW, using the Ebikes.ca simulator I came up with 1000-1100 motor rpm under load at the target voltage, which will put max speed in the 40-45mph range with the 28t/44t gearing I'm going to. That should be just about right for a 35mph cruise. Higher power plus lower gearing than I run on my big DD hubs should equate to much better hill climbing. I do 35mph up an 8% grade with my heavier DD bike, so I think being able to maintain 20mph+ up a 15% grade is a reasonable expectation while keeping the drive system out of the danger range, especially with both motor and controller well ventilated.