My new fat e-bike disappoints - how can I get more power!
 

Hi all,

I wonder if you can help me out. I recently bought a fat e-bike (spec below) with the dream of cycling to work off-road in all weather conditions (I'm in Switzerland where we have a lot of snow!). Anyway, there's a big hill between me and my work place (15km total distance/550 meters elevation gain) and needless to say my 26kg fat bike only just about limps up there and I even have to get off and push sometimes, I would probably be quicker on a light-weight mountain bike to be honest but let's not go there!

So the bike has a Bafang hub motor, not sure if it's a 350w motor that's been restricted to meet European laws or if it's really a 250w motor – I tried asking the company but they never reply whatever I ask them and only email contact is given so I can't even phone them.

https://www.surface604.com/fatbike/boar/

So anyway, has anybody got any advice for me? Can I just go and buy a bigger Bafang hub motor and replace it with my existing one – or should I look into getting an additional motor for the front wheel, not sure of any other options. Any help greatly received!

It looks like it has decent specs and cassette gearing for vaiable pedal assist. Is it not performing with pedal assist to your liking? If that is the case a larger motor may be in your future (and my 225lbs. future too!).

Up thru last year, I think Bafang only made one size motor that fits fat bikes. Does it look like this?This one is 350 watts and 36volts. I bought it for a fatbike, and I will install it when Spring comes. The controller I have is very small, and rated at 17A.

For more power with an existing motor, people look at bigger battery, a higher voltage battery, and a controller that can take advantage of more voltage and/or battery size.

These guys sell a controller for the Sonders fatbike that uses a Bafang rear motor, which I think is the same motor I have. The connectors look the same as mine. It could be compatible with your motor. After reading your plight, I think I will order one. You might contact the on their support email to see if it could fit your bike.

The bigger controller only works if you have enough battery to push the higher current. If your battery is too small, you're stuck.


Storm Hot Rod 25 amp controller BIG 36-60v - Luna Cycle


http://bikeforums.net/attachment.php...hmentid=514276http://bikeforums.net/attachment.php...hmentid=514277

As a SonDORS owner, I have been following the "mods" posts. The 25A controller will kill your battery in a big hurry. Go for the 20A version for some extra zip. The real answer is a bigger battery and motor if you really want to do hills. I think there is a 500w motor out there was well to fit fat bike wheels.

AKAIK Europeans get the 250w motors. Sadly I dont know how to tell them all apart by looks.

-SP

IMO, your bigger problem is that hub motors get very hot (obviously not in winter) when ascending at speeds less than about 8 mph (13 kph) or so. If it were me, I would sell this bike and procure a mid-drive.

My understanding is that the EU has limited their ebikes to 250w motors and anything larger than than breaks the law. If you're not worried about that, get an upgraded motor and controller (and may as well do battery while you're at it). I'm relatively new to these, but purely from an economical and technical standpoint, these "fatty" bikes are not the most practical candidates for ebikes anyway. They're big, they're heavy, they have huge fat tires that create ridiculous amounts of rolling resistance compared to normal tires - all things that are not overly conducive to an electric bicycle. They work, it's just not the most efficient system. If you're dealing with a single speed bike, it's even more problematic because you can't gear up or down for more power.