Search found 181 matches

by fourbanger
May 25 2020 1:15am
Forum: E-Bike Technical
Topic: Unloaded vs Loaded Speed?
Replies: 22
Views: 565

Re: Unloaded vs Loaded Speed?

Thank you for the reply. It's tough talking with sales reps without getting something along the lines of "yes yes, you buy now?" and it seems they keep their engineers and techs locked in the basement or something where I can't talk to them. One thing I've learned is that "yes" or "no" questions are...
by fourbanger
May 23 2020 3:45am
Forum: E-Bike Technical
Topic: Unloaded vs Loaded Speed?
Replies: 22
Views: 565

Re: Unloaded vs Loaded Speed?

So, um, preference aside, am I to understand it that the best motor of choice for a given form factor will ALWAYS be the one that achieves top efficiency at the highest RPM withstanding pole count, lamination width etc? I've always found it curios that so many sellers advertise their highest rpm mod...
by fourbanger
May 23 2020 3:24am
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 88
Views: 1544

Re: 40T, neodymium magnets, plasti dip cycle test

Bookmarked for further reading. Alls I knows is magnets aint so magnetic once theyses gets hot. What's to say of conductivity, I have no idea, except that as a rule of thumb resistance increases proportional to heat in a given conductor. Right? Thanks to SM for the link from https://endless-sphere.c...
by fourbanger
May 21 2020 11:47pm
Forum: E-Bike Technical
Topic: Unloaded vs Loaded Speed?
Replies: 22
Views: 565

Re: Unloaded vs Loaded Speed?

Interesting. I'd been wondering the same thing myself lately but was too embarrassed to ask. Actually, I'd been going on the premise of calculating top speed at 75% of no load rpm. But now that I really think about it what SM says makes a lot of sense. On the flat having had the throttle pinned for ...
by fourbanger
May 11 2020 12:31pm
Forum: E-Bike Non-hub Motor Drives
Topic: mxus xf15 gear hub motor teardown
Replies: 38
Views: 3175

Re: mxus xf15 gear hub motor teardown

Plastic ring gear, huh. Well that's pretty shabby even by MY low standards. FWIW, Grin Tech used to sell a code (9) swx02 that did 9.7rpm/v. I've yet to see another. I'll have to pick your brain some more regarding the delta/wye efficiency sometime. Sounds like there might be more to it than I thoug...
by fourbanger
May 11 2020 12:22pm
Forum: General Discussion
Topic: Active energy transfer balancing
Replies: 27
Views: 2349

Re: Active energy transfer balancing

Wow. That's just plain poor. Thanks for the heads up on THAT one.
by fourbanger
May 08 2020 10:18am
Forum: E-Bike Non-hub Motor Drives
Topic: mxus xf15 gear hub motor teardown
Replies: 38
Views: 3175

Re: mxus xf15 gear hub motor teardown

Been looking at this motor a bit myself lately. Thanks for doing the legwork on figuring out the RPMs and for the great pictures. A couple of questions, both of which might be somewhat foolish. How did we get from a 120mm x 18mm stator on page 1 to a 108x24mm on page 2? And, specifically (apart from...
by fourbanger
May 01 2020 12:14am
Forum: General Discussion
Topic: THE MODERN BICYCLE AND ITS ACCESSORIES
Replies: 3
Views: 249

THE MODERN BICYCLE AND ITS ACCESSORIES

Bit of light reading if you're into that sort of thing.

https://www.gutenberg.org/files/58444/5 ... 8444-h.htm
by fourbanger
Mar 27 2020 4:14pm
Forum: Items for Sale - Used
Topic: SOLD LeafBike / LeafMotor 1500W on 26 inch rim - Canada
Replies: 8
Views: 1336

Re: LeafBike / LeafMotor 1500W on 26 inch rim - Canada

Not worried about the paint, it's the whole stopping the bike thing I'm thinking aboot.

Thanks for getting back to me. Looking forward to your reply.
by fourbanger
Mar 27 2020 11:53am
Forum: Items for Sale - Used
Topic: SOLD LeafBike / LeafMotor 1500W on 26 inch rim - Canada
Replies: 8
Views: 1336

Re: LeafBike / LeafMotor 1500W on 26 inch rim - Canada

Appetizing! Will that wheel put up with rim brakes? Sure looks like it. Anyway you could afford to ship this sexy beast out to Victoria for 325$
by fourbanger
Mar 26 2020 1:31am
Forum: Items for Sale - Used
Topic: TSDZ2 5 miles of use $250 OBO
Replies: 5
Views: 1190

Re: TSDZ2 5 miles of use $250 OBO

Right on.
by fourbanger
Feb 13 2020 2:28am
Forum: Items for Sale - Used
Topic: Several A2B never version motors ( no controller inside )
Replies: 1
Views: 147

Re: a2b ultra motor bike parts

Just out of curiosity, what's the outside diameter of these motors?
by fourbanger
Oct 05 2019 1:18pm
Forum: General Discussion
Topic: Active energy transfer balancing
Replies: 27
Views: 2349

Re: Active energy transfer balancing

If by now you mean no then I think yes.

Wow. That was a weird sentence.
by fourbanger
Oct 05 2019 12:12am
Forum: General Discussion
Topic: Active energy transfer balancing
Replies: 27
Views: 2349

Re: Active energy transfer balancing

Inwo, thank you for offering your expertise on this matter. Before this thread grows too old, I'd like to ask your opinion of the super cheap active balance boards such as this. HTB1EwRgTq6qK1RjSZFmq6x0PFXas.jpg_220x220q90.jpg Are they any good at all or not even worth the fiberglass they're printed...
by fourbanger
Jul 16 2019 10:04am
Forum: Items for Sale - Used
Topic: SOLD! Used Tidalforce 26" Front Battery Hubs
Replies: 1
Views: 481

Re: Used Tidalforce 26" Front Battery Hubs

If someone could redesign these to run 20700s they could own the universe.
by fourbanger
Jul 01 2019 4:36pm
Forum: E-Bike Non-hub Motor Drives
Topic: Converting a hubmotor to a middrivemotor
Replies: 988
Views: 203603

Re: Converting a hubmotor to a middrivemotor

Hey, thank you for that offer. I'll have to get back to you on that, or you can give it to someone else who really wants it. I'm afraid I have at least one too many projects on the go already (honestly, probably like five too many) including a code 16 that I've re-terminated to delta that I'm still ...
by fourbanger
Jun 27 2019 12:12pm
Forum: E-Bike Non-hub Motor Drives
Topic: Converting a hubmotor to a middrivemotor
Replies: 988
Views: 203603

Re: Converting a hubmotor to a middrivemotor

I'm not entirely sure I agree with that statement about the BBSHD. The best thing about this conversion (as far as I'm concerned) is that it lets you pedal along at high speeds without spinning out whereas most other mid-drive setups--including the Bafang--will not allow for that. Also, I'm pretty s...
by fourbanger
May 19 2019 1:24am
Forum: E-Bike General Discussion
Topic: Bafang Bpm, how many RPM?
Replies: 126
Views: 44193

Re: Bafang Bpm, how many RPM?

That's a good question, I'd rather like to know myself; It's like a smaller BPM. I wonder how many RPM it can be pushed to until back EMF starts hurting.

BTW, where did you get that particular motor from?
by fourbanger
Feb 16 2019 8:07pm
Forum: E-Bike Technical
Topic: Mini Cyclone Motor RPM
Replies: 8
Views: 536

Re: Mini Cyclone Motor RPM

Well OK. But if we all somehow get sucked into a black hole or something I'm gonna be pissed.
by fourbanger
Feb 16 2019 5:33pm
Forum: E-Bike Technical
Topic: Mini Cyclone Motor RPM
Replies: 8
Views: 536

Re: Mini Cyclone Motor RPM

Right I got that bit and to be perfectly honest I have ZERO experience with these motors, so for all I know the thing really could be screaming its guts out at 8k+ rpm, but that just doesn't sound right to me. What I'm saying is that, hypothetically, if you had a 44/44t crankset with one chainring b...
by fourbanger
Feb 16 2019 1:20am
Forum: E-Bike Technical
Topic: Mini Cyclone Motor RPM
Replies: 8
Views: 536

Re: Mini Cyclone Motor RPM

No, you must have dilated the space/time continuum somehow. I keep telling people to be more careful with their cellphones. No one listens. If you had, say, a 44t chainring driving an 11t rear sprocket at a ratio of 1 to 4, a 268 rpm at the cranks would net you 1072 rpm at the wheel which would be l...