John in CR's ebikes

[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 941 times

Super V first side shot.JPG (28.19 KiB) Viewed 937 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.

[Ykick]

Nice to see your bikes and put a voice to your posts via podcast with grindz. Do you have any notes (or threads) regarding work with the Super V headset? Forks, triple tree, etc?

Thanks!

[John in CR]

Nice to see your bikes and put a voice to your posts via podcast with grindz. Do you have any notes (or threads) regarding work with the Super V headset? Forks, triple tree, etc?

Thanks!

I bought the SuperV as a complete bike, so I haven't touched the front end other than to swap out the wheel. I think the fork has a 7" travel. I really like the adjustment on it to tighten it up for no heavy brake dive. I also like the no worries about somehow snapping the forks off at the crown like I do with a typical fork (as unwarranted as the concern may be), but the limited turning range of the handlebars comes into play when moving it around while off the bike. It also robs some of the space I would otherwise use when I put batts on the downtube.

[Ykick]

Thanks John,

Those are beefy forks compared to the original SuperV headshok stuff. 'always looking for info about headsets and related parts for those bikes since that's what I'm now running with 9C kit.

Thanks for sharing the great work!

[liveforphysics]

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

Super V first side shot.JPG

Damn! That bike is going to haul ass! Torque monster!

[John in CR]

Damn! That bike is going to haul ass! Torque monster!

hehehe. The copy I want to make will have swingarm room for my big hubbies including brake drum cover for mounting the blowers. Then I snag a controller like yours, and go to max voltage. That's over 2100rpm no load and a motor proven to handle current to make controllers cry when sealed, so imagine what it can handle actively blown.

Just because I'm missing the Death Race doesn't mean I can't still have fun.

Then of course there's my monster hubbie I picked up since you were here. 270mm diameter stator with 50mm of laminations. The factory 60V60A controller propels a 300lb lead pig scooter to 45mph, and with 150lb rider up 20% grades. That's the one with dual halls, which will give me a bit of a 2 speed due to the advance timing on the high speed set of halls. Imagine higher voltage and current on 100lb bike.