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Comment by rhn_mk1 | Hacker News Reader

I'm not sure who's seriously interested in most of these features, fun factor nonwithstanding. One of bicycles' strengths is simplicity of critical elements, notably the gear switching. How do they make sure that the electronic system doesn't die on the rider when the battery goes flat? How do they deal with increasing slack in the lines?

Who really benefits from turn signals? Unless they are mounted on special stalks, it's going to be difficult to understand them anyway.

Other ideas are somewhat useful, like the car detector, or adjustable lights - I already thought about relating headlight power to speed or ambient light in 2011 (shameless plug: when I started working on Jazda - https://rhn.github.io/jazda ). But the power benefits of that may still balance out with the additional electronics needed.

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The whole point of electronic gear switching is that there is no slack in the lines - the shifters communicate wirelessly with the derailleur and the derailleur uses a small motor to execute the gearshift. It's actually awesome in practice - gearshifts are crisp and perfect each time, without the need for frequent adjustment or dealing with issues such as cable stretch and dirt. The batteries last a few months and if they die, you're stuck in one gear (you can change it at the side of the road with your hands if you get stuck in an undesirable one) - no big deal.

For a commuter / daily-driver bike without weight concern, I think a belt-driven internal planetary gearset with electronic shifting would be ideal as the bike nearly becomes a sealed unit, without any exposed grease or need for lubrication or adjustments.

I don't currently have much to add on the simplicity vs tech standpoint, but electronic shifting has been out for a while and there aren't really any problems with it.

Someone I know rides every day and said the battery lasts for about 4 months (looks like newer versions are rechargeable as well). There aren't any cables in the shifting mechanism. It is a set of shifters that are wirelessly connected to the derailleur.

FWIW, Shimano Di2 batteries have always been rechargeable.

SRAM's eTap wireless shifting system has a mix of rechargeable batteries on the derailleurs and non-rechargeable CR2032 batteries in the shift/brake levers.

I don't know what Campagnolo does, because I'm not interested in farm machinery. It is probably rechargeable by sending it back to an Italian specialist every two weeks. ;)

That's the SRAM system. Shimano has cables.

That said, I prefer my home built fixie: cheap to get great components, easy to maintain, and damn fun to ride.

I agree with you but Shimano has kind of built their entire business in the bicycle market on planned obsolescence, changing the number of gears to make equipment incompatible every few years and then making the highest end shifting electronic (and incompatible with prior versions) when they reached the practical limits of chain width for bicycles (they tried introducing a new standard chain size for bicycles that required replacing all the drive train components but that got rejected by the market, also they had more competitors back then). On the other hand Shimano dominates the bicycle market for bicycle components now and it's still only a tiny portion of their business - they sell a lot more fishing equipment.

This is a pretty good point. I also wonder how fixable bikes will be once they're "smart" and whether or not will still maintain "the right to fix".

One of the reasons why I absolutely love cycling, is that my bikes (and those of friends and relatives) are one of the only things left in my life I can fix myself, I save money and learn a lot from doing it, it's rewarding and incredibly cheap.

It would be really disappointing to see parts become a black box, more expensive and disposable.

Leave it to the eBikes I say.

That's another thing that gives me worries - or motivation. The electronical components are virtually guaranteed not to interoperate with competitor products (I hope I'm wrong though).

While electronics should open new hackability options, I'm afraid that's just not going to happen. ANT+ standard, for example, requires an NDA before you can make an implementation. Bike computers themselves don't have a serious open option (Jazda needs more work before it can be sold).

Brake lights would be a great addition, however. During fast stops, especially while commuting, it's nearly impossible to signal.

In Copenhagen people raise their hand to indicate a stop. I wish we'd adopt this in the U.S.

Do people have three hands in Copenhagen, because last time I checked my bike had two handbrakes, and I have to use both of them to stop safely?

If you have to use both brakes to stop your bike then your brakes are too weak.

Unless you're a 230lb cyclist coasting down a hill at 45mph and need to make a quick stop because a car up ahead does something stupid. I guarantee you that both brakes are required in that situation.

Not a professional bike mechanic (I build bikes as a hobby) but in general your front brake should be set up to be powerful enough on its own. This requires clean rims, and clean, non-worn, non-hardened brake pads.

But the front brake is normally controlled by the left brake lever, and signals are supposed to be given with the left hand. I've seen it argued that since most people are right-handed, and the front brake does most of the work and therefore deserves the most careful modulation, the usual practice is backwards: the right level should be for the front brake. I guess this is another reason. It makes sense to me, I guess, but not so much that I've actually bothered to swap the cables on my bike :-)

Anyway, in the wet it isn't always safe to use only the front brake.

In the UK the front brake is on the right.

The general non-emergency braking advice with derailleur bikes is to switch gears before stopping. While I can't speak for others, I do it at the same time. That requires a braking hand and a shifting hand.

A lot of people in Copenhagen (and other European cities) ride bikes with rear pedal breaks or “coaster brakes”. Which makes signalling easier as you have a free hand when breaking!

Also worth checking out is this signalling guide! [1]

[1] https://roadcyclinguk.com/how-to/technique/essential-guide-r...

ANT+ lights connected to a Garmin computer do this today.

Totally wireless.

Turn signals...

Could it just be a small and lightweight LED panel that flashed a bright arrow pointing in the intended turn direction?

With LED, it can be pretty efficient and still be really bright. I would think a blinking bright arrow would be fairly universally understood.

One issue is that now a lot of riders are using blinking lights all the time when riding for visibility reasons (during the day), so the arrow would need to be big enough to differentiate and visible front and back so now we could be talking about something much more obtrusive. If they're on the back, there's a limit to how big one can go (on easy to mount positions) because the rider's legs/feet/butt will strike protruding things from the bicycle.

Could they turn that blinking light into a an arrow at the appropriate time? I ride a motorcycle and have upgraded all my signal lights to the maximum legal output.

I would probably test to see if changing the colors was also effective. I don't think it would have to all that large, maybe half the size of an automobile license plate. When it is just going down the road, flash white. When it is turning, flash orange or red - in the shape of an arrow.

I'd test that and see how people responded to it. It might not even have to be that large. I'd just want to make it large enough that the arrow can be made out clearly and from, say, 100 feet away. The changing color may also help.

I suppose orange would be fairly standard and might be a good color choice to try.

Those sound like good ideas, though something that big would still have an issue fitting on something other than a recumbent or cargo bikes (often see lights that size already on those now).

I was thinking about that and it could just attach to the frame and then use something like an aluminum pole to hold it out over the rear tire. It'd be light and adjustable.

It'd look dorky, but it might save lives. I doubt it would add much weight or reduce aerodynamics very much, at least not as regular rider speeds. It's not like they would use it while racing.

Turn signals can help folks that have to bike up a hill and want to indicate they are turning. :)

For the rest, I agree it increases the failure likelihood, but it is probably heavily mitigated in some cases by the fact that most of the power can be generated by the biker. These are not large gears, so the shifting capabilities probably don't require plugging in. And they should "fail to on" such that if they go dead on power, you just can't shift. Can still use the gear you are in.

Turn signal would be useful. Just yesterday morning I was almost hit by a car when I was merging from bike lane to left turn lane.

You can just use your hands to indicate your intention to turn, this is done all over the world and AFAIK the accepted method of indicating without having any electronics.

Yeah of course I did that, but some drivers just know nothing about cyclists. Give them something they are more familiar with would certainly help.

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