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Comment by yilunzh | Hacker News Reader

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.

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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 it's seeing. It may eventually catastrophically fail on you.

At your given budget I would have used a better bike and a smaller motor/battery. The combination of beefy motor on an inferior quality bike could be flat-out dangerous.

> 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.

Ten hours is a lot. I've mounted two similar kits. Both took less than four hours.

People love to go on about the value of their time, but most people cannot arbitrarily decide to work another hour and get paid for it. Most people either have their schedules set by their employers or are on a salary that doesn't change if they add an additional hour.

Don't weight ten hours of learning about bicycle assembly as though it were ten billable hours if it isn't. Compare it against the ten hours you were going to do other things in: reading, watching TV, going out for a walk, whatever.

I think I'd rather read a book than keep monkeying around with a bicycle, though. That's the value of the time I'm referring to. I know some people like endless tinkering with things, but not me; I just want them working. Mechanical repair isn't a leisure activity for me.

Two types of people and all that. OP is clearly a tinkerer. Telling them that they shouldn’t value their time this way seems silly.

If I was the OP, I would do this exact thing: after putting some more miles on the bike and saving up that gas money, get a nicer bike and swap the motor. Better yet, sell this e bike for $2k now that it’s all upgraded and use that money for a full upgrade.

I don't think he'll be able to get $2K for it. It's still built around a bad bike, and any prospective buyer will easily find that out. It's probably worth most as parts.

Some HNers make me wonder if they could even enjoy a remote beach without finding a way to bill someone for it.

I would expect a cheaper alu frame to be "overbuilt" and heavier, probably not butted, so it doesn't seem that bad for the conversion.

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.

I've been getting interested in e-bikes recently. Work is 15km away, but I do weight near 0.1 [t] :)

Hows the battery holding if you carry extra weight? How much does the total setup, you included, weights?

I can comment on the range. I have a similar bike with a 540Wh battery. Total weight close to 20 kg, maximum practical range approx 30-40 km. Slightly less when sub zero C temp.

Edit: I would consider an extra charger and charge at work for that range, in case you want to stop by somewhere on your way to or back from work.

My bike is around 50 lbs. I weight about 150 lbs. I often carry a bag about 20 lbs. So all in, it's about 200 lbs or ~90KG. I think my battery pack can go about 50 miles per charge, but I never went that far on a single charge. I usually charge after 30 miles to ease strain on battery, but that should still be plenty for you to get to work and back.

I get 40km out of a 400Wh battery with similar weight. About half in cold weather with snow and studded tires. The tires seem to be the main reason for the reduced mileage. This is in sport mode with maximum assistance and going full speed.

V-brakes would have been more than suitable without the pointless disc brake faddishness.

Disc brakes are catching on, but for good reason: they increase the stopping power in rain substantially.

Though, it doesn't matter if you don't ride in the rain, and many people don't.

They also don't bleed as much braking power when they heat up from repeated or long braking, which is more common at the high speeds seen in an electric bike.

You'd be surprised at how little extra momentum (speed or weight) you have to add before disc brakes become essential. For me, the aha moment came when I started pulling a 40 lbs bike trailer - then you really don't want soft brakes when approaching a junction with cars. I installed some Avid Juicy's on 180 mm rotors and they're awesome - even now when the bike trailer is 70 lbs.

It's a cool project but it's not about "(riding) e-bikes", it's about "learning e-bike design by experiment"

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