Assembling a safe fast ebike

General Discussion about electric bicycles.
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Re: Assembling a safe fast ebike

Post by want to build » Sep 03 2020 11:09pm

e-beach wrote:
Jan 19 2018 11:13pm
NeedForSpeed wrote:
Jan 19 2018 10:37pm
I'm assembling my first high-ish power ebike (~3k-5k watts), and not wanting to die, I'm wondering what are the inherent dangerous aspects of a fast 2 wheel vehicle (the vehicle itself, not external factors like other cars). I want my ebike to be as safe as possible at high speeds, so I'm attempting to explore what it is that differentiates a (i'm assuming safer) DOT approved motorcycle from my hobby ebike, e.g. tires that can handle high speeds.

Has anyone given thought to this? So far all I can think of is wheel/tires that can handle high speeds/potholes, but I'm stumped what else could impact the safety of a high speed e-bike. What else can go wrong at high speeds?
Ok, define high speeds. First thing to know is that a bicycle is not a motorcycle. It is not even a scooter. Bicycle parts are not meant to be used at highway speeds the way motorcycle parts are.

As far as it goes lots of ES members have considered high speeds. I, myself don't go high speeds around my city because the car just don't see bicycles. How do I know? I have been hit by a car riding my e-bike. That is not to mention the close call when a car cut me off and stopped in front of me and I literally flipped my bike in the process of stopping. The only thing worse then flying over the handlebars and looking up from the wet gutter at a front wheel of a car is seeing the sidewalk coming before smashing your head into it after being hit by a car.

The problem with trying to stop from a high speed on a bicycle is that you don't enough tire surface to stop a heavy bike. You can lock up your rear tire but you will still skid for a while. Hit the front brake too hard and you wash-out or skid straight into what ever you are stopping for. Or flip over the handlebars if your front break is too good.

That being said those who use fast motors use moped rims and tires to become more motorcycle like. You should use a very well built DH frame and forks and scooter rims and tires.

And you should make sure your neck is a swivel because the cars are the most of your problems, not your least.

:D
hi what is a mopped rim i looked at picture and see no difference. how to you define it , eng second language L)

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 04 2020 10:22am

Easy to build speed, not so easy to make it safe.

First is geometry. Most bicycles are not designed for speed. Geometry corrections are a must, to achieve proper handling and braking of a fast ebike. I disagree with the previous comment about bicycle components and tires not being up to the task, simply because in the last 10 years I’ve maintained a shorter braking distance than ALL motorcycles with my fast commuters.

Then suspension. Bicycle suspensions that are suitable for speed, are made for off road. Mods are required to make a proper street suspension with MTB specific components.

Wheels and tires. Tires for fast ebikes need to be 2 ply clincher construction. Not so many available nowadays, but still enough to avoid the performance loss of heavy wheels. Heavy wheels are sucking acceleration performance, stretching braking distance, and make it very difficult to properly tune a bicycle suspension. The only good reason for motorcycle tires on a fast ebike, is to willingly sacrifice performance and grip for durability and puncture resistance.

It is expansive to build a fast ebike that has the stiffness and handling to match its speed and acceleration. Building heavy would require motorcycle components and start a weight escalade as consequence, so it does need to be sub 100 lbs ideally, or not much above at least. And, not only it does need to be light, it does need to be longer too. It is almost impossible to build a good 70 mph ebike at first try, so prepare for a lot of ‘try and error’, doing small mods and components replacement until the bike does behave.

After you got it though, it is the best city commuter that one could use, because it does combine bicycle privileges with motorcycle power. Silent and discrete, it can ride and park anywhere bicycles do. Yet, one could use a motorcycle at lesser cost in time and money.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Re: Assembling a safe fast ebike

Post by donn » Sep 05 2020 1:47am

wturber wrote:
Jan 21 2018 12:55am
You could go with a recumbent e-bike, and that may help, but then there's the visibility issue. So perhaps a better compromise would be to go with a stretched frame - especially one that might lower your riding position a bit.
Visibility doesn't need to be a big issue. You should have rear suspension, and that right there means the seat's going to be fairly high. I'm not looking over cars as I would on an upright, but my head's on the level with the driver in a small pickup for example. Long frame, weight on the rear. Will not be mistaken for an ordinary bicycle. A little less wind resistance.

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Re: Assembling a safe fast ebike

Post by Matador » Sep 07 2020 3:22am

I think you'd need:
1) Hydrolic disk brakes (those with mineral oil fluid not the cheap mechanical cable operated ones ones). You need big ass disks to shed the heat and big pads.
2) chromolly frame (not aluminium that's brittle and can brake whearas stell can flex a bit). Downhill frame ? Good idea.
3) DOT motorcycle tires (they wont melt/burst as bicycle tires can at speeds 45 mph or higher).
4) A high end heavy duty front suspension fork.
5) Some very very overbuilt torque arms/torque plates.
5) I would suggest a leather motorcycle suit, motorcycle helmet, motorcycle gloves. Spine support, body armor. You don't have much protections against incoming cars at these speeds.

Matador

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 07 2020 10:33am

Matador wrote:
Sep 07 2020 3:22am
I think you'd need:
1) Hydrolic disk brakes (those with mineral oil fluid not the cheap mechanical cable operated ones ones). You need big ass disks to shed the heat and big pads.
Almost right. Type of oil doesn’t change a thing to the performance of a caliper. We tend to prefer mineral oil for other reasons.


2) chromolly frame (not aluminium that's brittle and can brake whearas stell can flex a bit). Downhill frame ? Good idea.
That is a myth, any material can make good or bad frames. This is about who made it. And, where would you find a Downhil frame that is not Alu or Carbon? Only 2 had been made in the history if the sport.


3) DOT motorcycle tires (they wont melt/burst as bicycle tires can at speeds 45 mph or higher).
Another myth. Bicycle tires generally have better grip for the weight of ebikes, and there are many that are safe to ride 70+ mph, which many of us had been doing for a lot of mileage. Those who accept the weight and performance penalty of motorcycle tires, are doing it for reasons of puncture resistance and long lifespan.


4) A high end heavy duty front suspension fork.
Off road yes. Average suspension forks are doing pretty good on fast ebikes for street riding.


5) Some very very overbuilt torque arms/torque plates.
Obvious, for a hub build. All fast ebikes are not hub builds.


5) I would suggest a leather motorcycle suit, motorcycle helmet, motorcycle gloves. Spine support, body armor. You don't have much protections against incoming cars at these speeds.

Matador
Sorry. There were just too many misconceptions.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Matador   100 kW

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Re: Assembling a safe fast ebike

Post by Matador » Sep 07 2020 5:21pm

MadRhino wrote:
Sep 07 2020 10:33am
Matador wrote:
Sep 07 2020 3:22am
I think you'd need:
1) Hydrolic disk brakes (those with mineral oil fluid not the cheap mechanical cable operated ones ones). You need big ass disks to shed the heat and big pads.
Almost right. Type of oil doesn’t change a thing to the performance of a caliper. We tend to prefer mineral oil for other reasons.


2) chromolly frame (not aluminium that's brittle and can brake whearas stell can flex a bit). Downhill frame ? Good idea.
That is a myth, any material can make good or bad frames. This is about who made it. And, where would you find a Downhil frame that is not Alu or Carbon? Only 2 had been made in the history if the sport.


3) DOT motorcycle tires (they wont melt/burst as bicycle tires can at speeds 45 mph or higher).
Another myth. Bicycle tires generally have better grip for the weight of ebikes, and there are many that are safe to ride 70+ mph, which many of us had been doing for a lot of mileage. Those who accept the weight and performance penalty of motorcycle tires, are doing it for reasons of puncture resistance and long lifespan.


4) A high end heavy duty front suspension fork.
Off road yes. Average suspension forks are doing pretty good on fast ebikes for street riding.


5) Some very very overbuilt torque arms/torque plates.
Obvious, for a hub build. All fast ebikes are not hub builds.


5) I would suggest a leather motorcycle suit, motorcycle helmet, motorcycle gloves. Spine support, body armor. You don't have much protections against incoming cars at these speeds.

Matador
Sorry. There were just too many misconceptions.
Just my opinion. I don't claim to hold the absolute truth. I don't claim to be the absolute expert and I won't lose time searching for scientific publications to back my opinions . But I think that's what I would do. I feel like it's common sense. Mineral oil or whatever, as long as the brakes are hydrolic and not cable driven, as I said. Can't go wrong with a motorcycle helmet and suit. DOT tires are homologated for these kinds of speeds so I don't see harm in these... Yes they are heavier, but does it matter so much if you have a lot of power.

Torque are for hub, not for mid-drive.... Euh duh ?! I didn't think I would have to explain this on the endeless-sphere.
Maybe we can't find downhills of chromolly today okay, I guess I'm wong on this one. But you can weld one of you're so inclined. As for good suspensionforks sure if you don't want one go for a standard bike fork.

If you want a cheap 100$ waltmart bike with a 10 kW kit, maybe you can build one and ride it at 65 mph. For me, at speeds like that I'd rather have an overbuilt dependable bike with a solid structure, than a temporary cheap bike with a powerfull kit that might just snap in half.

Again, just my opinion. Nobody asked me to defend a doctorate thesis on the subject. I thought this post was about suggestions and opinion. I that's what I gave.

One more thing:

Don't be sorry, it doesn't make you anymore right or wrong.

With all due respect,

Matador

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 07 2020 6:38pm

@Matador

Too long to quote.

Nothing personal. That is why the ´sorry’.

You are not the only one to have those misconceptions. They have been repeated ad nauseam on ES, so many are believing them.

Believe it or not, steel is not the best material to build a fast ebike. It is the material you want to chose if you buy a cheap bike, but cheap bikes are not suitable for fast ebikes.

Safety equipment is minimal common sense. I never recommended anyone against it.
Safety is also in grip and handling, and motorcycle wheels are compromising many safety factors on ebikes: longer braking distance and slower handling especially, because of the moment of inertia. They are made for the weight of motorcycles, that is the problem. When riders choose to use them, I recommend to select in the moped or trial category because they are made for lighter motorcycles. And, if you value DOT norms so much, why don’t you ride DOT brakes? We can do better than motorcycles, we have to, because fast ebikes are something else, better in many ways, or at least they should.

Many are believing that weight is an advantage for fast ebikes. That too, is a myth. Lighter weight had always been the main target of bike design, motorcycles, bicycles, any 2 wheelers. This is for better control and performance, and on ebikes it does affect efficiency/range that are so important parameters for any builder.

I like the old heavy duty forks to ride the mountain. That is a weight compromise that I accept because robust suspension and large wheels are making a faster ride in the mountain trails, where speed is limited by terrain. On the street I use a light weight modern racing fork that I tune to shorter travel and smaller wheels. A 7 lbs fork does make a safer street bike than a heavy duty 12 lbs fork, because a lighter front does make faster reaction in emergency situations.

There are too many misconceptions about fast ebike design. That is because lots of people are associating them with motorcycles, and want to apply norms that are set for much heavier bikes that are riding much faster. If we are building with motorcycle norms in mind, we need to target motorcycle speed and size as well.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Re: Assembling a safe fast ebike

Post by John in CR » Sep 07 2020 8:00pm

Matador wrote:
Sep 07 2020 5:21pm
...5) I would suggest a leather motorcycle suit, motorcycle helmet, motorcycle gloves. Spine support, body armor. You don't have much protections against incoming cars at these speeds.

Matador
The more protection you have the more aggressive you will tend to ride. While this may not be true for everyone, I know with certainty it is for me, because I saw my average speeds increase once the transit police kept insisting I wear a helmet. It's also part of the reason that countries that implemented mandatory helmet laws saw no increase in overall safety. With only shorts, t-shirt, flip flops, and no helmet, the vast majority of sane people will of course ride with maximum focus and care. If you're the type who thinks it's ok to listen to music, send and read texts, talk on the phone or anything else that distracts from your focus while riding on 2 wheels, then yeah you probably should armor up.

I miss the days of when I could get away with a baseball cap as my helmet. The absolute focus on the road and my surroundings was a liberating time free from thinking about anything else.

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Re: Assembling a safe fast ebike

Post by Matador » Sep 07 2020 8:08pm

@ MadRhino

No worries. No hard feelings at all.

I'm actually really glad to read your detailed explanations. I do have some misconceptions (i'd be a fool to think I don't).

I'm a man of science, but I'm not an engineer. I do love physics, maths, chemistry and I enjoy thinkering with wood, a soldering iron etc. In another life I would have liked to be a mechanical engineer. But in reality, my work is done at the microscope. On day I'll get myself a tig or mig welder and start building stuff in my garage. Maybe an ebike frame. I think I can see how it's not just the material that make a frame robust, but also the way it's structure is built. A bit like the honeycomb pattern in some material used in building airplanes can be at the same time robust, yet very light.

The way you write, you seem to have some good insight how to build stucturally sound ebike frames. I guess the paradigm still need to evolve. EBikes are not motorcycles. Fast eBikes are better than motorcycles.

These chapters on "material/structural physics of ebikes" and "physical and dynamics factors that influence handling of eBikes" are some of the eBikes aspects I am the least familiar with. I mean we talk a lot about motors, controllers and batteries, but I feel that understanding how to chose the optimal structure and parts for an eBike is a subject that hard to circumscribe. At least for me. Experience most likely helps. Empirical testing of different frames, forks, wheels, brakes in different environnenents, to find out what works best. But I don't know what set of rules, physical laws and principles to rely on to get it right a the first shot.

I don't have DOT brakes myself. I have a 300$ nakamura bike from sport expert shop that I installed a 1000W BBSHD. I also have a cheap chinese Ancheer 250W rear geared hub 20 inch wheel foldables and to electric skateboard (and 288 sony VTC4 cells I will need to use one day to build a big ads battery for a more powerfull ebike. Got the cells by buying them off from Doctobass. i actually met him in person in Quebec City. Quite a knoledgeble guy too.

Anyways. Interesting topic and discussion. I'm quite surprised about DOT not being so good in the case of eBikes, but now I understand better due to your eplanations.

BTW, why use mineral oil ? Why not just use standard brake fluid?

I know I have misconceptions. That's why I want to learn more and correct these msiconceptions. Reminds me when I started here on the ES. Tried to build a plexiglass solderless battery with laptop recycled 18650. It did not deliver as I expected. Thst did not turn out ideal. But did learn a lot in the process, and intend to use this new knowlege to build better bikes in the furure

Matador

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 07 2020 10:36pm

Mineral oil has two advantages: it is not corrosive, and it is hydrophobic.

DOT brake fluid has some important advantages too, but it is corrosive and hygroscopic (meaning it does absorb some water).

Mineral oil has no expiration. It doesn’t change with exposition to air or water, forever. DOT brake fluids have a limited life, because they are corrupted by the exposition to air or water. The exception is DOT 5, that is silicon based and doesn’t age (not performing good though, because it is more compressible).

Now the strong points of DOT brake fluids. Even the lowest grade of them (DOT 1) has a higher boiling point than mineral oil. DOT brake fluids are rated for, and perform better at high temperature (the higher the DOT #, the higher the temp rating). They don’t change much volume with temperature change because they are glycol based, thus perform better in the cold too.

Most bicycle brakes were using DOT brake fluid at the beginning, but many have changed to mineral oil since. Three reasons for this: Fluid changes were leading to stupid mistakes, stripping the paint of expansive bikes. Bikes were sometimes left in stock or storage longer than brake fluid life. Brake fluid was also sleeping in bike shops longer than its useful life.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Matador   100 kW

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Re: Assembling a safe fast ebike

Post by Matador » Sep 08 2020 6:43am

Cool. Yeah DOT brake fluid is not fun to work with for sure. Recently had to dismantle a brake caliper with sieze piston on my subaru because the car had sat too long and environnement was wet and humid (and the inexperienced mechanic that had done previous brake maintenance did not seem to have use any silicon grease on the piston dust boot so the piston rusted). Seem like my brake fluid was old and maybe contaminated with water wich could have accelerated the rusting. Had to take all my calipers appart and rebuild them with new pistons and square seals. Fun to learn about brakes. While i has there, i sanded the rust on the caliper and gave them some red caliper paint and gloss finish.
Last edited by Matador on Sep 08 2020 7:19am, edited 1 time in total.

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 08 2020 7:14am

I have many big bicycle brakes. The best at the tests is the Hope mono 6 ti, that runs with DOT fluid. But the maintenance is PITA, although not often required. My overall favorite is the Magura Gustav M, that I still use on the rear of some of my bikes after 15 years. Maintenance is often but very quick and easy. The brake I use the most is the Magura MT7. I have it on the front of all my bikes. I find its precision unbeatable, but it is a brake that needs girlie touch to maintain. Lightweight parts easy to damage in assembly, and expansive to replace. I like the Shimano Saint, not as precise but cheaper to maintain. Long lasting on the rear, but nowhere near a good old Gustav.

My favorite rotors are Hope v2 225mm on the front. On the rear I use many different: Magura Venti, Hayes, any that are thick enough for my big calipers spec.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Re: Assembling a safe fast ebike

Post by John in CR » Sep 08 2020 7:36pm

My favorite brake is continuously variable regen braking. Then any mechanical brakes will do, though I definitely prefer hydraulic as they're so easy to set up and they self adjust. My disc brakes are now used so little that they require virtually no maintenance, but they're always there cool and ready for emergency stopping.

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 09 2020 2:16pm

John in CR wrote:
Sep 08 2020 7:36pm
My favorite brake is continuously variable regen braking. Then any mechanical brakes will do, though I definitely prefer hydraulic as they're so easy to set up and they self adjust. My disc brakes are now used so little that they require virtually no maintenance, but they're always there cool and ready for emergency stopping.
Yep. Cheap to brake with regen. But it does not achieve a short braking distance. In city trafic I consider this a bad habit. That is a situation where experienced usage of a good front brake is a must. I always start braking with the front. In emergency situation on dry pavement, the rear brake is useless because my rear wheel is not touching the ground. On the wet, or slippery winter conditions I use regen to keep the tail behind.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Re: Assembling a safe fast ebike

Post by 99t4 » Sep 10 2020 12:04am

John in CR wrote:
Sep 08 2020 7:36pm
My favorite brake is continuously variable regen braking.
What do you use to vary the regen? Another throttle control?

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Re: Assembling a safe fast ebike

Post by John in CR » Sep 10 2020 2:09am

99t4 wrote:
Sep 10 2020 12:04am
John in CR wrote:
Sep 08 2020 7:36pm
My favorite brake is continuously variable regen braking.
What do you use to vary the regen? Another throttle control?
I run a regular twist throttle that is cut quite short on the left side, so the twist is backward. On my son's ebike we put a left side thumb throttle to control regen. I'm still up in the air which I prefer. Neither is perfect, but quite adequate, and after a short time becoming accustomed it works fine. I still have a good grip on the bars, can modulate brake handle fine for brake lights and mechanical braking force.

When someone comes out with a low cost solution in a brake handle that has a brake light switch and can modulate a regen brake signal I'd give it a try, but then what to do about the lever for the second mechanical brake? Maybe some kind of trigger type for one finger to pull is the right answer for regen

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Re: Assembling a safe fast ebike

Post by donn » Sep 10 2020 9:11am

John in CR wrote:
Sep 10 2020 2:09am
When someone comes out with a low cost solution in a brake handle that has a brake light switch and can modulate a regen brake signal I'd give it a try, but then what to do about the lever for the second mechanical brake? Maybe some kind of trigger type for one finger to pull is the right answer for regen
What about the other brake? I'd expect the usual, regen on one and not the other - may be missing something here.

Anyway, if you're a front braker like MadRhino above, I suppose anything will do for a regen control, but if your emergency braking reflexes focus on braking the rear wheel, I think it's asking for trouble for that to involve two different controls. For the ideal safe fast ebike.

Or an optional second control that defeats the mechanical brake - so if it isn't an emergency, and you just want to pump up the regen but not touch the disk, you could thumb the anti-brake while you squeeze the brake lever.

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Re: Assembling a safe fast ebike

Post by ZeroEm » Sep 10 2020 9:45am

by Matador » Sep 08 2020 6:43am

Cool. Yeah DOT brake fluid is not fun to work with for sure. Recently had to dismantle a brake caliper with sieze piston on my subaru because the car had sat too long and environnement was wet and humid (and the inexperienced mechanic that had done previous brake maintenance did not seem to have use any silicon grease on the piston dust boot so the piston rusted). Seem like my brake fluid was old and maybe contaminated with water wich could have accelerated the rusting. Had to take all my calipers appart and rebuild them with new pistons and square seals. Fun to learn about brakes. While i has there, i sanded the rust on the caliper and gave them some red caliper paint and gloss finish.
When working auto brakes need to flush out old fluid, it gets contaminated with moisture, rubber and metal from wear. Disc brakes rust when not used.

My trike has dual front mechanical disc brakes on 20" wheels. Put on a dual brake leaver and keep it adjusted so it does not pull left or right. last adjustment was 6 months ago, last brake pad adjustment was 9 months ago or 1000 miles give or take. The only rear brake is variable regen. I use this first, most, get the speed down and in combination with front brakes that are used to stop the trike or for surprises. Maybe someday I will need to replace the pads, I do adjust them when ever I work on tires rotate them or replace.

My question to everyone is why a second throttle for regen? I put a button for regen close to throttle and use throttle to vary my regen but I have no brake other than regen on that side.
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Re: Assembling a safe fast ebike

Post by John in CR » Sep 10 2020 11:29am

donn wrote:
Sep 10 2020 9:11am
John in CR wrote:
Sep 10 2020 2:09am
When someone comes out with a low cost solution in a brake handle that has a brake light switch and can modulate a regen brake signal I'd give it a try, but then what to do about the lever for the second mechanical brake? Maybe some kind of trigger type for one finger to pull is the right answer for regen
What about the other brake? I'd expect the usual, regen on one and not the other - may be missing something here.

Anyway, if you're a front braker like MadRhino above, I suppose anything will do for a regen control, but if your emergency braking reflexes focus on braking the rear wheel, I think it's asking for trouble for that to involve two different controls. For the ideal safe fast ebike.

Or an optional second control that defeats the mechanical brake - so if it isn't an emergency, and you just want to pump up the regen but not touch the disk, you could thumb the anti-brake while you squeeze the brake lever.
For fastest braking I go all the way with the regen twist and brake with the front as hard as necessary. It helps that I run mine like on a motorcycle, ie front brake handle on the right. I still have a rear mechanical brake with handle on the left because I don't want any possibility of only ending up with one brake on a mountain descent if regen goes out. Since regen by its nature is anti-lock I can get maximum braking for emergency stops when combined with front. I look pretty far ahead and ride with focus assuming vehicles never see me, so they're pretty much non-existent anyway. The rear tire chirps a bit, but can't skid. I use my left brake handle (rear mechanical) all the time though for my brake lights and to hold in place when stopped on an incline, and use my front brake very little. I brake with regen for well over 90% of my braking, but I have bigger loads, longer wheelbase, and much lower CG than bikes like MadRhino, so I get much more braking force possible with the rear.

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 10 2020 12:29pm

Shortest motorcycle braking distance is the Aprilia Tiono. I believe it is possible to beat it with an ebike. I beat all motorcycles that I tried for braking, but I am still at a longer braking distance than the Tiono from 60 mph. Example in slow motion:

Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

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Re: Assembling a safe fast ebike

Post by dogman dan » Sep 12 2020 9:56am

I'm still real big on emergency change of direction when the shit really hits the fan. As you ride, always have that escape plan evolving. Am I going to swerve right or left when that dumbass pulls out of that parking lot. You might need to turn into that parking lot in a hurry. Can't do that riding too fast though so often the evolution of the escape plan is slow down before the shit hits the fan. Saved my ass sooo many times. You plan on that guy turning into your path, because he often does.

Your chances of actually stopping in time are minimal if you are flying in a stupid place to do it. But if you have better brakes, you can go faster and still stop in time. If your brakes are not the greatest, slow down more in front of that walmart.

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Re: Assembling a safe fast ebike

Post by MadRhino » Sep 12 2020 11:09am

Yep. There is always one unpredictable idiot to force you to emergency braking. We can anticipate most of the situations, but some people are proving everyday that human behavior can be defying logic.

We need all the options to avoid the worst scenario, ant it does mean being trained and ready for all of them. Building and tuning the bike properly is an important part of ‘being ready’. Then, the rider too, need to be tuned. He must know his ride performance, handling and limits, enough to never have any doubt in emergency situation, as to choose the best option and acting confidently. The time lost in hesitation might be the last.
Make it fool-proof, and I will make a better fool.
Current bikes
Street:
Trek Session 10 mod. Variable geometry. 70mph
Dirt:
Santa Cruz V10. 50mph

raylo32   100 W

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Re: Assembling a safe fast ebike

Post by raylo32 » Sep 14 2020 8:30am

Your main problems with a fast e-bike is not you, but cars, pedestrians and other variables out there. I routinely ride my road bike hitting 50 mph on downhills and it is safe as far as the bike itself goes, but others are not going to see you or expect you to be going that fast. For a pedal road bike this isn't too much of an issue because these speeds happen for only short periods and generally on low traffic country roads with no intersections and few driveways. You get to doing this in an urban environment it is a lot more problematic. I also have a motorcycle so am somewhat comfortable in traffic but you need to be alert at all times and ride safely because in any collision you will lose.

John in CR   100 GW

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Re: Assembling a safe fast ebike

Post by John in CR » Sep 15 2020 1:41am

raylo32 wrote:
Sep 14 2020 8:30am
Your main problems with a fast e-bike is not you, but cars, pedestrians and other variables out there. I routinely ride my road bike hitting 50 mph on downhills and it is safe as far as the bike itself goes, but others are not going to see you or expect you to be going that fast. For a pedal road bike this isn't too much of an issue because these speeds happen for only short periods and generally on low traffic country roads with no intersections and few driveways. You get to doing this in an urban environment it is a lot more problematic. I also have a motorcycle so am somewhat comfortable in traffic but you need to be alert at all times and ride safely because in any collision you will lose.
The great thing about our electrics is how easy it is to get extreme performance. I'm not talking about speed in particular other than enough speed to pace traffic and a bit more. It's acceleration that I use to stay safe in traffic. I say that because I don't let cars near me. I move around between and ultimately in front of them with ample empty space behind me. I run full lights and have a horn, so the only remaining risk, ie traffic entering from the sides, is more likely to see me, though I'm always alert to be able to avoid anything entering the road from side streets. I also don't ride along side vehicles other than a brief time while passing them. The way I ride I create so much space between myself and vehicles that it would be quite difficult for someone to hit me...even intentionally. I chose my own interactions with vehicles and ride assuming none see me until I've confirmed they actually have, so things such as getting right crossed are virtually impossible.

raylo32   100 W

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Re: Assembling a safe fast ebike

Post by raylo32 » Sep 15 2020 4:59am

Yup, you ride like a motorcycle. I ride my road pedal bike in city traffic like that. But lots of motorcyclists still die. You can pretend that you are choosing all the interactions with other vehicles... and you can indeed choose many... but there are plenty of idiots out there who won't see you... and you won't always be able to find them before they find you. Be careful.
John in CR wrote:
Sep 15 2020 1:41am

The great thing about our electrics is how easy it is to get extreme performance. I'm not talking about speed in particular other than enough speed to pace traffic and a bit more. It's acceleration that I use to stay safe in traffic. I say that because I don't let cars near me. I move around between and ultimately in front of them with ample empty space behind me. I run full lights and have a horn, so the only remaining risk, ie traffic entering from the sides, is more likely to see me, though I'm always alert to be able to avoid anything entering the road from side streets. I also don't ride along side vehicles other than a brief time while passing them. The way I ride I create so much space between myself and vehicles that it would be quite difficult for someone to hit me...even intentionally. I chose my own interactions with vehicles and ride assuming none see me until I've confirmed they actually have, so things such as getting right crossed are virtually impossible.

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