Search found 6898 matches

by Chalo
Mar 26 2019 3:04pm
Forum: E-Bike General Discussion
Topic: Are there any full suspension bikes that can hold a large 72v 25ah triangle battery?
Replies: 8
Views: 181

Re: Are there any full suspension bikes that can hold a large 72v 25ah triangle battery?

2old wrote:
Mar 26 2019 10:54am
The last possibility is early 90's URT (universal rear triangle) models where the shock wasn't in the front triangle. The design wasn't popular, so it may be difficult to find.
"Unified rear triangle", if you're keyword searching.
by Chalo
Mar 26 2019 2:56pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: overall friction penalty: 80% less top speed?
Replies: 6
Views: 234

Re: overall friction penalty: 80% less top speed?

The plan is to install a QS 273 8kW V3. I guess the real question is what specs should I tell them so that they provide the proper winding for 80kph actual top speed? Figure out what wheel RPM corresponds to 80kph: https://www.4qd.co.uk/road-speed-calculator/ You know you're looking for 5kW power o...
by Chalo
Mar 26 2019 1:30pm
Forum: E-Bike General Discussion
Topic: Looking for robust 24'' rim
Replies: 51
Views: 1422

Re: Looking for robust 24'' rim

When lacing a motor with centered flange, what exactly speaks against lacing alternating elbows in and out? An inside spoke has less bracing angle than an outside spoke. So you give up some lateral stiffness and strength when you lace spokes inside the flange. With a large hub motor and a small rim...
by Chalo
Mar 26 2019 12:46pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: overall friction penalty: 80% less top speed?
Replies: 6
Views: 234

Re: overall friction penalty: 80% less top speed?

There's only true if the available power supports such speed. In this case, that's very doubtful. So help me out here, why is it "in this case, very doubtful" that a well-designed eScooter's pack wouldn't be able to support 80kph if the unloaded max is 100kph? First of all, 80kph will take about 5k...
by Chalo
Mar 26 2019 2:41am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Cemoto OS110C E-scooter starts bogging down after 15kms
Replies: 4
Views: 58

Re: Cemoto OS110C E-scooter starts bogging down after 15kms

Lead acid batteries are usually rated for their capacity at C/20 discharge-- 20 hours to empty. That means the nominal power rating of the OP's scooter is roughly 100 times greater than the battery's nominal capacity discharge rate. Those batteries are not even approximately 20Ah batteries at 100x h...
by Chalo
Mar 25 2019 10:25pm
Forum: E-Bike General Discussion
Topic: Saved by thumb throttle
Replies: 6
Views: 145

Re: Saved by thumb throttle

Don't forget the new crank arm. There's nothing you can do for the one that fell off. For what it's worth, you can feel the crank wiggling for a while before it goes off on its own. But if it wiggled around much, you'll still need to replace it. Purple Loctite is the low strength kind. When mine cam...
by Chalo
Mar 25 2019 10:02pm
Forum: E-Bike Non-hub Motor Drives
Topic: Proper Middrive Shifting technique?
Replies: 6
Views: 123

Re: Proper Middrive Shifting technique?

Shifting under power in either direction is abusive to the chain and sprockets, and should be avoided whenever possible. If I hold the throttle in a steady position though is it really shifting under power? Yes. Modern gears are designed to be able to complete a shift under load, but it still puts ...
by Chalo
Mar 25 2019 8:09pm
Forum: E-Bike Non-hub Motor Drives
Topic: Proper Middrive Shifting technique?
Replies: 6
Views: 123

Re: Proper Middrive Shifting technique?

Shifting under power in either direction is abusive to the chain and sprockets, and should be avoided whenever possible. The noise is worse when upshifting, but it's just as damaging when downshifting-- possibly even bending sprockets or dislodging chain pins.
by Chalo
Mar 25 2019 8:04pm
Forum: E-Bike General Discussion
Topic: Saved by thumb throttle
Replies: 6
Views: 145

Re: Saved by thumb throttle

Since pedals don't attach with a bolt, I assume you're talking about the bolt that attaches the crank arm to the bottom bracket spindle. Once the arm has dislodged once, the square taper hole becomes distorted and will continue to loosen due to rotational play. You have to replace the arm. Once you'...
by Chalo
Mar 25 2019 6:42pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Cemoto OS110C E-scooter starts bogging down after 15kms
Replies: 4
Views: 58

Re: Cemoto OS110C E-scooter starts bogging down after 15kms

My guess? The lead batteries are beat down. If you run those things hard, they die very young. If you discharge them deeply, they die very young. If you fail to recharge them immediately... well, you probably get the idea. Due to Peukert effect, the capacity of your batteries is nowhere near its nom...
by Chalo
Mar 25 2019 6:06pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: overall friction penalty: 80% less top speed?
Replies: 6
Views: 234

Re: overall friction penalty: 80% less top speed?

Loaded speed is typically ~80% of unloaded speed. This is a function of back-EMF, and tire friction, air resistance, etc are secondary losses on top of that. There's only true if the available power supports such speed. In this case, that's very doubtful. It is a fact that motor efficiency tends to...
by Chalo
Mar 25 2019 4:03pm
Forum: E-Bike General Discussion
Topic: Help whit Gazelle BMS
Replies: 7
Views: 125

Re: Help whit Gazelle BMS

Based on the numbers of wires, it looks like the BMS is in the other end of the case.

Every BMS I've ever worked with had a separate light gauge sense/balance wire to each cell group.
by Chalo
Mar 25 2019 11:42am
Forum: Items for Sale - Used
Topic: $5000 OBO GreyP 12kw E-bike - Mint Condition w/ just over 200 miles
Replies: 7
Views: 641

Re: $5000 OBO GreyP 12kw E-bike - Mint Condition w/ 91 Miles

but what stands out with this bike, is the special geared crank, allows you to pedal at 43 MPH... and the bike is built to be able to pedal - get this - - EFFECTIVELY. My power calculator says you incur something like 250W of extra drag by pedaling at 43mph versus not pedaling. So sure, you can mak...
by Chalo
Mar 25 2019 11:15am
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 487

Re: Lead acid anyone?

I used Hawker Genesis batteries in several of my scooters and they were the best at the time. That's what I used in my first two e-bikes. [Edit: Actually, they were Hawker Odyssey.] Then I went back to regular pedal bikes for several years, because I decided that was better. I'd do it again, if lea...
by Chalo
Mar 25 2019 2:02am
Forum: E-Bike Build Threads / Photos & Video
Topic: Music Barrel
Replies: 14
Views: 249

Re: Music Barrel

I made a bass amp out of a 20 liter heavy-walled plastic pail some years ago. I made a tuned port so it would be responsive down to 41hz (the lowest note of a bass guitar). I'd need to make one tuned a little lower for the six string bass I'm working on learning to play a little. :) It's the same l...
by Chalo
Mar 24 2019 10:10pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Music Barrel
Replies: 14
Views: 249

Re: Music Barrel

I made a bass amp out of a 20 liter heavy-walled plastic pail some years ago. I made a tuned port so it would be responsive down to 41hz (the lowest note of a bass guitar). The 10" full-range boat speaker and 40W mono amplifier I used sounded so nice that later I used it as a vocal amp for my croone...
by Chalo
Mar 24 2019 9:54pm
Forum: E-Bike General Discussion
Topic: Front vs. rear hub motor
Replies: 16
Views: 1066

Re: Front vs. rear hub motor

Build a bike like you would choose a horse. We like them with a powerful hind and light front. Those that are heavy on the front, are unfit for riding. My front-heavy bike with a front hub motor can carry your rear-heavy one, but the reverse is not true. It's fit for riding and for day to day livin...
by Chalo
Mar 24 2019 9:22pm
Forum: E-Bike General Discussion
Topic: Front vs. rear hub motor
Replies: 16
Views: 1066

Re: Front vs. rear hub motor

Build a bike like you would choose a horse. We like them with a powerful hind and light front. Those that are heavy on the front, are unfit for riding. My front-heavy bike with a front hub motor can carry your rear-heavy one, but the reverse is not true. It's fit for riding and for day to day living.
by Chalo
Mar 24 2019 8:52pm
Forum: E-Bike Technical
Topic: Cooling Solutions?
Replies: 28
Views: 358

Re: Cooling Solutions?

Thermal compound does not act as a glue. It is a paste that fills-in all the tiny irregularities between the two surfaces. It is formulated to easily transfer heat between the two surfaces, but...it's pricey. So... try to attain a good fit before adding thermal compound. Not only is is expensive, b...
by Chalo
Mar 24 2019 8:47pm
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 487

Re: Lead acid anyone?

Archer321 wrote:
Mar 24 2019 7:33pm
I still use lead-acid in my racecar because that is the class I run in.
Ugh. What "racing" class is that?
Image
by Chalo
Mar 24 2019 3:10am
Forum: E-Bike Technical
Topic: Cooling Solutions?
Replies: 28
Views: 358

Re: Cooling Solutions?

Noticed that the motor on my e bike (mini cyclone) runs pretty hot. On the outer casing while pushing the bike hard I can get it to go as high as around 140 degrees f or about 60 degrees c (can't touch the motor for more than a few seconds). I definitely would like this temperature to go down and I...
by Chalo
Mar 24 2019 3:00am
Forum: Battery Technology
Topic: New weldless battery system crowdfunfing project
Replies: 70
Views: 1999

Re: New weldless battery system crowdfunfing project

This is why solderless packs aren't a mechanical design problem to solve as much as a materials tech challenge to select things that won't let force creep down to nothing after sitting a while. This seems to me to be a point in favor of using a high tensile strength copper alloy as both bus and lea...
by Chalo
Mar 24 2019 2:43am
Forum: E-Vehicles General Discussion
Topic: What does this charger behavior indicate?
Replies: 17
Views: 421

Re: What does this charger behavior indicate?

I built my own pack from automotive cells. There are few physical points of failure, but there is a relatively inexpensive BMS card that I didn't make. 1 in 25 fault rate for a component that's made in at least a semi-automated manner would be anomalous in my world. The thing I installed was all SMD...
by Chalo
Mar 24 2019 2:08am
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 487

Re: Lead acid anyone?

So I know lithium ion is the current hot stuff right now, but is anyone still running on lead-acid batteries? There have been several reported advancements that are supposed to be coming to market in the next two years. Lead/graphene-acid and bipolar lead-acid to name two. I think you'd have to be ...