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    Rivian's TM-B electric bike

    (www.theverge.com)
    217 points hasheddan | 14 comments | 22 Oct 25 18:00 UTC | HN request time: 0.658s | source | bottom
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    ChuckMcM ◴[22 Oct 25 23:32 UTC] No.45676493[source]▶
    I tend to agree with comments that point out that 'modern' e-bikes are really electric motor cycles or the original "MoPed" from the 60's. And they have the same appeal, relatively cheap to operate, fit in between regulatory categories, don't require a garage to store, Etc. E-scooters aren't much better (just worse kinematics). That said, I never thought the Segway was ever going to be more than a 'niche' product whereas I had already lived in a city[1] with thousands of mopeds. To the extent they are embraced by urban planners with reduced parking mandates and their own roadways I think they are a net win for cities, when they terrorize pedestrians on sidewalks, not so much.

    [1] Brussels.

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    1. conradev ◴[23 Oct 25 05:43 UTC] No.45678519[source]▶
    The one thing about e-bikes that I don't get is: why the chain?

    https://www.voromotors.com/products/emove-roadrunner-v3-seat...

    This thing has 500W hub motors, no expensive derailleur, no chain to maintain, just tires and brakes. The hub motors have internal gearing. I love mine for getting around LA.

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    2. iancmceachern ◴[23 Oct 25 05:48 UTC] No.45678550[source]▶
    Torque, electric motors need gearboxes just like everything else
    replies(1): >>45678919 #
    3. beAbU ◴[23 Oct 25 06:32 UTC] No.45678827[source]▶
    That thing you linked to is not a bike, it's a motorcycle. It should be licensed, taxed and insured like one.
    4. loeg ◴[23 Oct 25 06:38 UTC] No.45678861[source]▶
    That isn't a bicycle. It's a scooter.
    5. defrost ◴[23 Oct 25 06:46 UTC] No.45678919[source]▶
    This doesn't address the question "why a chain" though.

    Many motorcycles have grunty torque, gearboxes, and no chain: https://en.wikipedia.org/wiki/Category:Shaft_drive_motorcycl...

    The BMW R 100GS Paris Dakar was the bee's knees for crossing the Tanimi Desert: https://www.motorcyclespecs.co.za/model/bmw/bmw-r100gs-pd-89...

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    6. scotty79 ◴[23 Oct 25 09:17 UTC] No.45679867[source]▶
    I think the chain makes sense you want to let the rider pedal. If you don't, hub motors are the obvious way to go.
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    7. actionfromafar ◴[23 Oct 25 09:36 UTC] No.45679967[source]▶
    "The rider pedals a generator, which replenishes the battery, "

    The chain is probably to keep unsprung weight low. Hub motors are not the best for comfort.

    replies(1): >>45680267 #
    8. actionfromafar ◴[23 Oct 25 09:38 UTC] No.45679983{3}[source]▶
    Shaft drive is more expensive to produce, tends to be a little heavier, and usually has more friction loss.
    replies(1): >>45680173 #
    9. defrost ◴[23 Oct 25 10:05 UTC] No.45680173{4}[source]▶
    Shaft drive delivers power better, wears less than a chain, easier to maintain.

    Swings, roundabouts, and tangential from answering why "Torque, electric motors need gearboxes" doesn't answer the progenitor question "why chain".

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    10. jnsaff2 ◴[23 Oct 25 10:12 UTC] No.45680217[source]▶
    Unsprung weight.
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    11. scotty79 ◴[23 Oct 25 10:21 UTC] No.45680267{3}[source]▶
    Why is that? Do you want sprung mass to be heavier or unsprung mass lighter?

    I see how lower unsprung mass could be easier on the tyres but I have no idea how it could impact a rider who's isolated by full suspension.

    12. tim333 ◴[23 Oct 25 11:29 UTC] No.45680637[source]▶
    The chain is to connect the pedals to the rear wheel as you might expect, assuming you want to be able to pedal.

    I see the rivan thing has a toothed belt rather than chain.

    13. onli ◴[23 Oct 25 11:43 UTC] No.45680724{5}[source]▶
    My bike vendor likes chains. They wear more easily, but are easy enough to maintain and change. Basically everything old school bike like has maintenance/repair advantages.

    I'm not sure I agree, but more when compared with belt drive and internally geared hub. But then again, I believe him that those are hard to repair when they fail (even if they are sturdy until then).

    14. conradev ◴[23 Oct 25 12:19 UTC] No.45680990[source]▶
    The answer I was looking for! I was looking for the trade-off