The Add-E 600W Kit is exceedingly compact, light weight and easy to remove (for temporary unpowered use) though it does produce more noise than most of the ebike kits I’ve tested. The bottle style battery pack is beautiful, the cap twists to add power at 50 watt increments up to 250 making it legal internationally, limited top speed of 15.5 mph. Lots of optional accessories including a twist or trigger throttle, the included five magnet pedelec disc isn’t super responsive but works well and qualifies as Class 1. Compatible with a wide range of bicycle types but may require extra work to install (completely removing the bottom bracket), solid six month battery warranty.

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