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First 100 miles on my E-Bike

yilunzh.com

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Re: First 100 miles on my E-Bike

#101

Post by CydeWeys »

monkmartinez wrote: post #90
CydeWeys wrote: post #66

Earlier quoted context omitted.

You can't easily replace the frame though. You're right that the other parts can be replaced, but you should have at least used a good frame to start with. For only a few hundred bucks more you could have gotten a substantially better bike to work with. The bike you have has a cheap aluminum frame, which will accumulate stress fractures over time from the high speed electric bicycle use exceed its design specs that i…

> You can't easily replace the frame though. You can. You just move the motor, battery/controller to another bike. What the author did is a great way to check the feasibility of the idea for himself without breaking the bank.

It took him ten hours of work the first time. Yes, it'll take him less the second time because he's gotten better at it, but it's still by no means easy or trivial. And we haven't gotten to how much he values his time yet.

Re: First 100 miles on my E-Bike

#102

Post by dmurray »

mantas wrote: post #85
dmurray wrote: post #43

Earlier quoted context omitted.

100 watts would turn it back into a manual bike with some electrical assist. There's a place for that, but it's clear the author was looking for something more.

E-bikes are bicycles with electrical assist. Fully motorised bikes are mopeds or, well, motor bikes.

Yeah, I'd count the author's bike as being pretty close to being a moped. Except that it might get regulated as an e-bike, and it is possible to use it as a normal heavy bicycle if he wants or if the motor fails.

Re: First 100 miles on my E-Bike

#103

Post by CydeWeys »

celim307 wrote: post #86
yilunzh wrote: post #20

Earlier quoted context omitted.

Yup, the brakes is definitely the limiting factor currently, but other parts of the bike have held up surprisingly well. I didn't really know anything about bikes before starting this, so it was a cheap way to learn. I figured I can always upgrade the parts over time if needed. I had set a max budget of $1500 for the initial purchase and had to make tradeoff somewhere.

Checkout bikesdirect. Same price as Walmart, much better quality. I can personally attest to their road and track bikes

I got a Liberty CXD and have been using it for over a year now with only some slight modifications -- I replaced the pedals (they were trash) and added fenders, a rear rack, and lights. I chose that bike as a good compromise between performance and not breaking the bank too much if it got stolen.

Were I to do it over again I'd get a nicer model, because in practice I almost never lock up my bike outside anyway so the theft concerns aren't an important factor.

Re: First 100 miles on my E-Bike

#104

Post by revelation »

CydeWeys wrote: post #76
revelation wrote: post #72

Earlier quoted context omitted.

Most humans can't sustain 250W on a simple ergometer for 20 minutes. At 1000W, you are a motorcycle, not a bike. If that is what you want, fine, but then stick to roads, stay off bike paths.

Are those two figures comparable though? Is an electric bicycle motor measured by its power draw or by its output? And either way, it's still not the same because at most that'd be measuring at the crank, whereas an ergometer measures at the pedal. So if I had to guess I'd say that a 1000W electric motor is roughly equivalent to, say, 500W output from a human on an ergometer (which of course is still way better than…

It's hard to build an inefficient electric motor, and I'd think the headline figure is the motor power rating.

But even if we assume it's the power draw and the motor itself is terribly inefficient, we're still talking 80% efficiency? Chain drive is 95% efficient if badly maintained, but then the human power loses that, too, so we don't need to consider it. So we're still talking 800W, which is 3-4 times as much as needed to sustain 20 mph on flat ground, and utterly out of range of any human for any time period beyond a minute.

The power and speed limit of normal ebikes is a feature. It keeps us from making the same mistake we have with cars, which only ever got faster while driving discipline declined and were at any point beyond human ability anyway.

Re: First 100 miles on my E-Bike

#105

Post by analog31 »

JKCalhoun wrote: post #99
analog31 wrote: post #59

>>> If the ride is so great and economics so favorable, why haven’t I seen more adoption here in US and Canada? The author's answers to this question focus solely on the bike technology itself. This is a common thread in a lot of discussions about cycling: If we only built the right bike, more people would ride. This is usually followed by a CAD rendering of the perfect bike, that looks like nobody would want to ride…

> including the fact that driving a car is fun for a lot of people Hmmm... Communting to work is fun for people? I want to live where they live. Keep the car for weekend cruising, the bike probably makes the boring commutes more fun than a car would. I built an bike 6 or 7 years ago but only took it once to work (a 20 mile commute). It was underpowered and under-batteried but it was an interesting starting point. I m…

I think a lot has happened in the past few years, so that it's worth trying an improved motor and battery system.

Winter is a great time to get geared up for the next season, and there might be some seasonal discounts to take advantage of right now!

Re: First 100 miles on my E-Bike

#106

Post by beachy »

VLM wrote: post #77
noonespecial wrote: post #37

Earlier quoted context omitted.

I actually worry about the "something must be done" crowd cajoling lawmakers into lazily shoehorning electric bikes into the "motorcycle" category and erasing much of their advantages to own as a bicycle. This happened with boats here as my little plastic kayak with a tiny electric assist has to be registered and taxed as if it was a full sized bass fishing boat with a v8.

I would worry about the kit aspect of the bikes. You're lucky to merely have to pay some money for your "power kayak". In my state, to actively discourage the construction of home built boats, if I want to build a 15 foot sailboat, I need to work with the coast guard and state DMV (spoiler, they don't actually work together, the finger pointing is hilarious) to get a hull number assigned, then fight the DOT to get it…

That sounds like insanity. My country by comparison is too far at the other end of the scale. Anyone can buy (or make) a boat, with a 200 horse motor, grab a six pack and a tank full of fuel and hit the water and go anywhere, into any harbour, with no training whatsoever.

Re: First 100 miles on my E-Bike

#107

Post by ufo »

tonyedgecombe wrote: post #16
Brakenshire wrote: post #12

Earlier quoted context omitted.

I've read about motorized doping in bike races, with motors hidden inside the gearing, I wonder whether anyone's thought about this sort of thing for consumer bikes, and what sort of benefit you could get for, say, 1kg or half a kg of extra weight. E-bikes at the moment seem to have reconciled themselves to being twice the weight of ordinary bikes.

Something like this: https://www.vivax-assist.com/en/product/vivax-assist/vivax-a... I think the problem is range, you won't be able to hide much battery, the one on my bike weighs 6LBs and is quite bulky. In reality it doesn't really matter because the motor will more than offset the extra drag and weight of a heavy bike.

Can you pedal and use the motor at the same time in a regular ebike? I think what the parent posters want to be able to turn off the motor completely.

Re: First 100 miles on my E-Bike

#108

Post by Brakenshire »

tonyedgecombe wrote: post #16
Brakenshire wrote: post #12

Earlier quoted context omitted.

I've read about motorized doping in bike races, with motors hidden inside the gearing, I wonder whether anyone's thought about this sort of thing for consumer bikes, and what sort of benefit you could get for, say, 1kg or half a kg of extra weight. E-bikes at the moment seem to have reconciled themselves to being twice the weight of ordinary bikes.

Something like this: https://www.vivax-assist.com/en/product/vivax-assist/vivax-a... I think the problem is range, you won't be able to hide much battery, the one on my bike weighs 6LBs and is quite bulky. In reality it doesn't really matter because the motor will more than offset the extra drag and weight of a heavy bike.

> I think the problem is range, you won't be able to hide much battery, the one on my bike weighs 6LBs and is quite bulky.

Interesting, that seems to be exactly what I was thinking of. The good thing is, it seems you could use it without a battery, or with differently sized batteries depending on need. If I'm reading this right, the motor, wiring, etc, weighs about 1000g, then a 6Ah battery another 850g, or a 9Ah battery 1250g. So only an extra kilo if you just wanted to use it as a normal bike, and if you're commuting, you might know exactly what capacity you need, and could just take that. Especially in cities, there's a lot of carrying bikes up and down stairs.

Just needs to be a lot cheaper than 3000 Euros!

Re: First 100 miles on my E-Bike

#109

Post by CydeWeys »

jordache wrote: post #98
CydeWeys wrote: post #79

Earlier quoted context omitted.

Mechanical disc brakes certainly do not work nearly as well as hydraulic disc brakes in high-power-output electric bike applications. What they "worked" on is manual bikes, but even for manual bikes, hydraulic brakes are superior; it's just that a manual bike isn't pushing the limitations of what mechanical brakes can do as often.

hydraulic mostly provides improved actuation via greater modulation resolution. Think about it - It's a hydraulic system vs mechanical. No cable stretch and no friction along brake housing. However greater modulation resolution is not a major benefit in the context of ebike. The bike is heavier so you just need sufficient braking power. A larger rotor radius would help more than going from mechanical to hydraulic. hy…

I get what you're saying, but in practice, cheap mechanical disc brakes also suffer from less braking force, whereas there aren't particularly cheap hydraulic disc brake systems, so all the hydraulic disc brakes do have better braking force in addition to greater modulation characteristics.

So to simplify the point I'm making, he needs better brakes.

Re: First 100 miles on my E-Bike

#110

Post by ricardobeat »

That attached battery would get stolen in a pinch. Not practical unless you have closed/safe parking at every destination, i.e. won't work in Europe where we mostly park on the street.

I'm curious about the second picture: it looks like the motor is in the way of the pedal crank arm?

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