There are some people who feel no need for an ebike during regular cycling, but who would like an electric assist when pulling a trailer. Well, that's where the new motorized Ein trailer is designed to come in.
Manufactured by Danish ebike company Biomega, the Ein (German for "one") features a monocoque polypropylene shell, an aluminum frame/arm, and a single rear wheel that's equipped with a 250-watt hub motor. That motor is in turn powered by a lithium-ion battery located in the trailer body, which can be removed for recharging.
According to Biomega, whenever the cyclist starts from a stop or speeds up, the trailer wheel's increased spinning motion is detected. The motor instantaneously responds by kicking in proportionally, keeping the wheel moving at that speed until a bicycle slow-down is detected. In this way, the motor essentially cancels out the extra towed weight of the trailer.
Speaking of which, the Ein can be used to carry either inanimate cargo – protected under a rainproof plastic lid, if needed – or up to two small children in attached third-party standard-size seats. There's no word on the weight of the trailer, or on its maximum payload weight, although it does reportedly have a battery range of 85 to 150 km (53 to 93 miles) per 5-hour charge.
The Ein is claimed to lock securely to a corresponding aluminum hitch, mounted on the bicycle's seatpost. Additionally, when parked, both it and the bike are propped up by a flip-down kickstand on the underside of the trailer.
Should you be interested, the Ein is presently the subject of an Indiegogo campaign. Assuming it reaches production, a pledge of €745 (about US$890) will get you one – the planned retail price is €1,195 ($1,428). You can see it in action, in the video below.
A somewhat similar product, the Brouhaha trailer, failed to meet its Kickstarter goal. The $799 Ridekick, however, has been available for several years now – and while its cargo capacity is significantly less than that of the Ein, it does function as a bike booster, actually pushing the attached bicycle forward.
Source: Indiegogo
And it needs to hitch to the rear axle or it'll make the bike handle badly if loaded especially.
Just buy an E bike of your choice, I like the 20" wheel step throughs folding or not.
Then get a axle hitched 2 wheel trailer that carries weight low.