![]() My opinion is this: Make an informed decision, and if you do decide to go down the illegal route, be prepared to accept the potential consequences. The demand (in the UK at least) seems to be for more powerful electric bikes, a lot of people are unsatisfied with the law as it stands and are willing to take the risk. The big downside is they are ungainly and inefficient.ĭespite the 250w legal limit in Europe, an increasingly large number of riders are using 500w, 1000w or even 1500w converted e-bikes on the road. The Direct-drive electric bike hub motor is certainly very reliable and capable of lasting for years. I don’t feel that they are particularly suited to mountain bikes, due to the extra weight in the rear wheel, and the lack of torque.Ĭheap DIY twist-and-go electric commuter bike – a great idea, but unfortunately totally illegal in some countries. This is about the same amount of torque produced by a good quality 36v 250w geared hub motor, on the other hand, a decent 250w mid-drive system like the Bafang or Tongsheng will produce closer to 60nm of torque.īecause of their durability and simplicity, large direct-drive hub motors can handle very high power outputs – because of this, they are very popular in electric bike racing (on closed circuits). To put things into perspective, a typical cheap 1000w electric bike conversion kit with a good quality 48v battery fitted will produce roughly 35-45nm of torque. This puts most direct-drive hub motors firmly in the ‘illegal’ category in these countries. UK, European and Australian laws are 250w continuous power output with assisted speed limited to 15.5mph (25km/h). The big downside is they are ungainly and inefficient. Federal e-bike law in the USA states a maximum power output of 750w and assisted speed of 20mph – the bike has to have functioning pedals.ĭirect-drive hub motors are certainly very reliable, and are capable of lasting for years. This poses a legal problem in a lot of countries. The most important thing to consider (for UK, European and Australian riders) is the power output.ĭue to their size and weight, most direct-drive hub motors are usually rated to 500w and above. This really depends on what you are going to be using your bike for. This will mean that you may lose a couple of gears on the back.Īnother issue can be the brake calliper may rub on the hub casing, and also the rear derailleur may do the same when the lowest gear is selected – this can be mitigated by fine-adjustment of the derailleur’s limit screw. Another thing to consider is having an extra 4-5kg in the front wheel is definitely going to have a negative impact on handling.Ī rear-mounted hub motor is best, but there will still be compromises to consider when fitting: If your bike has a cassette-type gear block, then it will not fit, as all the direct-drive hub motors I have come across, only have fitted for a screw-on Shimano type gear freewheel. If your bike has disc brakes, it is highly likely that there will be not enough space between the brake calliper and the hub casing. Personally, I think a powerful front hub motor is a bad idea, regardless of the legality of the motor. The drag of the motor can make pedalling harder (especially with the motor switched off) Front or Rear?. ![]()
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