Search found 2843 matches

by speedmd
Oct 25 2021 8:33am
Forum: Bike Mechanical & Structural
Topic: Ruined $150 Shimano Deore hydraulic brakes
Replies: 80
Views: 929

Re: Ruined $150 Shimano Deore hydraulic brakes

One thing is clear. Brakes need to have standard, published metric's. Heat- temp limits, energy dissipation /time and or possibly duty cycle are a few I would like to know before specifying them for a tubby on a high power e-bike. We are all just pissing in the wind without them. Plastic piston seal...
by speedmd
Oct 25 2021 7:53am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Sure wish he would start sharing that new high potency medical crop for times following crashing bad in the rock garden. :lol:
by speedmd
Oct 14 2021 7:33am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Paywalled ! Anything revealing inside that article ? I had the same question. Way too cheap to pay to read it however :oops: Most likely the brief exposed bits say what needs to be understood, that the stuff is way too expensive for cheap EV manufacturers and they are focusing on markets with deepe...
by speedmd
Oct 13 2021 9:02pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Many are selling 2022 auto models now and claim is the 2025-26 models will have access to the Lyten lithium sulfur cells. Looks like capacity (Need faster 3D graphene process?) is being promised out to the aviation players at the moment on a prototype basis. https://aviationweek.com/aerospace/urban-...
by speedmd
Oct 06 2021 10:00pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

The pack size & weight is unchanged (20-25 kg) and the max power drain is limited to 120 kW still Most likely it is not much lighter but has a bit more capacity. Thermal management (current rollback) is a big issue in this app so the claimed lower resistance of the new cells most likely adds a ...
by speedmd
Oct 06 2021 12:04pm
Forum: Alternative Energy
Topic: evaporative air cooling, made better than HVAC
Replies: 25
Views: 1960

Re: evaporative air cooling, made better than HVAC

it would appear the condensor rad is condensing the water out of the air. Exactly! That is how I am understanding it also. It is "fogging" the air, by bringing it closer to the dew point. I picked up some of those mini temp-humidity sensors I linked earlier for another app recently and th...
by speedmd
Oct 06 2021 11:55am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Looks like Honda introduced a new battery in F1 recently. Claim to be lighter and more efficient. Very secretive about it.
https://www.youtube.com/watch?v=WUjEE2sG3Lw
by speedmd
Sep 23 2021 9:40am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

400whr/kg very possible in less than 5 years The PRnews clip suggest a 900whr/kg max potential. Looks like they are using the theoretical limits of what can be achieved with surface enhancements on the graphene. With added surface area at work C rates should not be effected unless they take signifi...
by speedmd
Sep 22 2021 3:02pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

3d graphene looks trick but how scalable is it. May drive cost a bit. Here is another article on them. https://www.prnewswire.com/news-releases/lyten-introduces-next-generation-lithium-sulfur-battery-for-electric-vehicles-301383071.html Minus 30 cold capable and 1400 cycles sound good. Little to No ...
by speedmd
Sep 16 2021 7:13am
Forum: Alternative Energy
Topic: evaporative air cooling, made better than HVAC
Replies: 25
Views: 1960

Re: evaporative air cooling, made better than HVAC

Interesting change adding a condenser- radiator on the output stage. Looks to me that its condensing more moisture in the output air which would increase the ability of the air to absorb more heat. A few of these sensors would go a long way explaining what is going on in the various stages for littl...
by speedmd
Sep 13 2021 3:16pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Interesting that a carbon sulfur honey comb matrix with hard "rubbery" candy coating may save the world. :lol: Must be something in the sugar that sticks very well to the structure as on ones teeth but protects it in this case.
by speedmd
Aug 22 2021 7:32am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Ionic ("charged") liquid electrolyte vs a partially ionic polymer slurry. Looks like much the same concept of ionizing oils and additives which have had some of the big improvements in motor oils the past decade. This may be significant if it proves out to be as durable and safe as claimed.
by speedmd
Aug 18 2021 6:16am
Forum: EBike Non-hub Motor Drives
Topic: What speed in relation to the no-load will you go
Replies: 12
Views: 410

Re: What speed in relation to the no-load will you go

Good point on the adjustability of field weakening. Playing with the simulator I noticed some significant broadening of the power, rpm-efficiency band plot width using a BBSHD - Phase Runner vs the standard controller pulldown options. That and field weakening would greatly improve the drivability o...
by speedmd
Aug 17 2021 6:11am
Forum: EBike Non-hub Motor Drives
Topic: What speed in relation to the no-load will you go
Replies: 12
Views: 410

Re: What speed in relation to the no-load will you go

What if I’m overpowered! Not that such a thing exists but how about 180 amps and a max no-load speed of 43mph? Can I expect to get up to 43mph with a strong drive/motor? If you are overpowered, you can reach or exceed the no-load max speed with a Field Weakening capable controller. Avner. Field wea...
by speedmd
Aug 16 2021 9:20am
Forum: EBike Non-hub Motor Drives
Topic: What speed in relation to the no-load will you go
Replies: 12
Views: 410

Re: What speed in relation to the no-load will you go

With wind resistance and other resistances adding to the load on the motor what percentage of the motor’s no-load speed is achievable? What is the resistance level of your rig (aero and mechanical) and what is the available power? Impossible to figure without some estimates. From what I understand,...
by speedmd
Aug 11 2021 6:15am
Forum: Vendor Relations Corner
Topic: east gem and paypal issues
Replies: 35
Views: 735

Re: east gem and paypal issues

Ebay, I shop for deals. They now charge tax and tried several times to get the paperwork done to buy supplies for resale items tax free, but gave up after the repeated hurdles involved. Shipping is a bitch also. Not possible to let them have access to the main business account as they are not to be ...
by speedmd
Aug 10 2021 8:04am
Forum: Vendor Relations Corner
Topic: east gem and paypal issues
Replies: 35
Views: 735

Re: east gem and paypal issues

I stopped using paypal to sell. More than twice the costs of the other methods out there for vendors. I found it very difficult to deal with them when something goes wrong also.
by speedmd
Aug 05 2021 7:05am
Forum: EBike General Discussion
Topic: Keirin racing - now I've seen everything
Replies: 27
Views: 643

Re: Keirin racing - now I've seen everything

Haven't caught much track racing in the olympics. But my favorite is the team pursuit. The way they ride is so perfect it looks like its a video game
I caught the team final yesterday. WOW. A must see! Hopefully youtube will have it saved in some way.
by speedmd
Aug 05 2021 5:35am
Forum: EBike General Discussion
Topic: Keirin racing - now I've seen everything
Replies: 27
Views: 643

Re: Keirin racing - now I've seen everything

neptronix wrote:
Aug 04 2021 8:53pm
That's a cool bike but looks like hell to sit on.
When your putting 1KW into the pedals, you don't feel the seat! :lol:
by speedmd
Aug 04 2021 8:21pm
Forum: EBike General Discussion
Topic: Keirin racing - now I've seen everything
Replies: 27
Views: 643

Re: Keirin racing - now I've seen everything

What caught my eye mostly was the Lotus.

Image
by speedmd
Aug 04 2021 1:12pm
Forum: EBike General Discussion
Topic: Keirin racing - now I've seen everything
Replies: 27
Views: 643

Re: Keirin racing - now I've seen everything

They use any bike that can go fast enough to pull away. Not one type. 40MPH minimum I would guess as the pack is easily riding 36+. I spotted a specialized and something looking like a stealth. Big betting sport in Japan and has been for decades. Lots of crashes. :twisted:
by speedmd
Aug 04 2021 10:29am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

Can Anyone shed a light on this ?
We were hoping you would! :lol:

All looks like a bunch or PR hype to me. Virtually no technical details and broad unspecific claims. But if they can produce a low cost mass storage battery with good cycle life and safety, it is worth keeping a eye on.
by speedmd
Aug 04 2021 8:27am
Forum: EBike Troubleshooting
Topic: upgrading phase wires gone wrong
Replies: 12
Views: 384

Re: upgrading phase wires gone wrong

Is it running higher RPMs also or just lower torque? Sounds to me like a bad connection as mentioned above. Digital non contact thermometer will spot it if so. Should show higher resistance on a multimeter also.
by speedmd
Aug 03 2021 6:13am
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1769
Views: 279105

Re: Thread for new battery breakthrough PR releases

I am not finding claimed efficiency nor any hydrogen production. https://www.alexhsain.org/blog/ironair https://patents.google.com/patent/US20120187918A1/en Efficiency. An iron-air battery has an open circuit cell voltage of about 1.28V and a theoretical energy density of 764 Wh/kg. While the curre...