Nice summary of available ekits. Of course they all void any remaining Brompton warranty, so might be best used on older bikes outside the warranty period. Though ARCC does provide its own warranty for both the kit and the bike. Note front hub motor kits are going on the standard fork and not the reinforced Brompton electric fork, so that may or may not prove an issue down the road. Comparisons of which kits add resistance and if so how much when riding with e-assist off. We don't always want to use e-assist. As for price, the Brompton electric is about $1500 more than the non-electric, so I would factor that in when looking at kit prices. Of course, you can't retrofit your non-electric Brompton with an ekit from Brompton, so I think a third party ekit would only be good if you already have a regular bike. For me, I wish Brompton would put a manual controller on the handlebars for changing assist level and showing battery level ... they have BT so just do something like ARCC does, instead of thinking we want to put our phones on the handlebars (no I don't...ever). Other than that, I would just prefer to buy the Brompton ebike.
Thank you for your comment. Actually, I'm still confused; perhaps there are certain limitations, such as how large the ideal motor size for designing and using on bicycles in general. Imagine, until now, there hasn't been any major bicycle company capable of making a hub motor or e-bike kit that is truly silent like a direct motor (not gear-driven as usual). There are indeed some options like pure magnet direct motors, but their size is too big. On the other hand, they have zero friction when the e-bike is not in use. I once used the ADD E-NEXT directly when in Taiwan; this solution is quite good because if the e-bike is not activated, the motor doesn't come into contact with the rear tire. However, there are some minor drawbacks, such as the motor slipping on the tire during heavy rain or on sandy surfaces. In my opinion, the motor for an e-bike doesn't need to be designed with a high wattage. 100-200 watts is already sufficient because, on average, people can generate power around 180-250 watts per person. With an additional 200 watts, it's already very comfortable for riding and doesn't detract from the exercise effect.
@@denielnoya Good points. Yeah, not sure any ebikes are totally silent...then again my regular bikes are not totally silent, so there is that. Motor sizes are a bit complex, even discussing only those which stay within legal boundaries. EU/UK allows 250w with max 25kph (15mph) assist and no throttle. US allows up to 750w with max 20mph (32kph) class 1 or 28mph class 3 pedal assist, tmax 20mph class 2 throttle. Then there are hub motors vs mid motors (same as central motors), but front hub motors can be front hub or rear hub. I think of it as mid motors do more with less wattage than hub motors and with hub motors tire changes will be easier with front hub than rear hub (so I don't care about the other front/rear hub differences). You see more mid drives in eu/uk because of 250w limit. In US, you see more front hub drives because they are cheaper than mid drives plus easier to deal with than rear hubs (and probably cheaper as well). Now, wattage... I think of 250w mid drive being roughly equivalent to 500w hub drive for average weight people on flats and mild hills, or 750w for heavy people and/or very steep hills. Bike gears will aid the motors so the motors don't need to work so hard...if you bother to use your gearing, which really only matters on hills (if you want your motor to last longer). So ... hub motors... in flat country with or without wind 250w is fine, hilly country 500w or 750w depending on how steep are the hills. Gearing... starting to see some bikes with automatic gears. Think cars with manual shift vs auto shift; it still shifts gears in either system. Same with bikes. Then there are cadence sensors (cheaper, assist levels at fixed speeds per level) vs torque sensors (adjust assist to effort you are pedaling but you set level for how much assist). Interestingly, Brompton ebikes (which I am saving up to get) use a torque/cadence assist with a front hub 250w motor and hill handling depends on how many gears you have (ie 2, 3, 4, 6, or the new 12)...more gears, easier on hills and faster before spinnout on flats; also has no drag when not using motor. Drag...does the bike pedal like a regular bike when you are not using the motor (ie battery died, or you just don't want assist)? Is it too heavy to pedal eithout the motor? Make sure you test and see for yourself. That's all I can think of for now. It's simplified but for me practical. Hope it helps.
