I've been looking at converting one of my bikes into an ebike and would really appreciate some input.
I'm a fairly experienced short range bike commuter, I live and work in the city, haven't owned a car in 3 years, and am perfectly happy doing all my everyday errands and commuting on a conventional bike.
I find myself more frequently going to visit family that are about 20 miles from where I live, and am primarily looking for a way to speed up this trip, or make it more palatable when I need to bring a decent load with me.
I don't necessarily want to make the ride any easier, but where I average 20 mph for the ride right now, if I keep my effort even, I'd love to be able to average more like 25-30 mph. Also, when I have 30-50 lbs of stuff to take with me i can barely average 15mph, and generally loath the trip.
Ideally, I would like to convert the cheap cyclocross frame bike I have hooked up with a rack and panniers for this. This is my grocery/errands bike, and while I'm in the city, I don't think I'll have any real desire to have it run on battery power.
So, If I can average about 20 mph for an hour long trip, what type of power from the hub will it take to get me averaging around 30mph?
I would like to keep this bike fully functional without battery power, would a front hub only system work fine for a 150lb rider and 50 lbs of stuff (keeping in mind that I have no problem pedaling hard)?
Direct drive vs geared hubs. I like the sound of a geared system in that they have no rolling resistance when not providing power, but I've heard they are less useful at higher speeds and have a potentially shorter lifespan. How much of this is true, and how much resistance does a direct drive hub have when not assisting?
Any input is welcome, as are suggestions for specific kits that may fit what I''m looking for. Thanks.
resistance on direct drive hubs varies. The crystalytes (at least the older ones) have the most resistance of any of them but they also have some of the most acceleration power. I have a Crystalyte and a Forsen hub motor. The Forsen has almost no resistance at all and it's a direct drive. It won't take much more to go from 20 mph to 30 mph if you can pedal at 20 mph. You could probably do it on 36v setup. 36v might be the best anyway because it would be lighter. Do you anticipate hitting very bumps or hopping many curbs? With a front hub, it's pretty hard to do a wheelie up onto a curb. I would say basically impossible to do that. So if you plan hitting bumps or hobbing curbs, you'll want to probably get a rear one. You have to be careful dropping from sidewalks or getting up on sidewalks. I always take it really slow and if the drop is more than a few inches, I usually will walk it down. You have to also think about how bumpy your roads are. You probably want some kind of suspension on your bike if you are planning on going 30 mph. The best geared hub that I know is the ezee but it tops out at around 18 mph for 36v and 22 mph for 48v so I don't know if you'll be able to get up to 30 mph with that or not. You might contact http://ebikes.ca and tell them you are a good cyclist and see what they think about the Ezee kit. The Ezee kit would be a pretty light setup. The battery is small and I think motor is pretty light as well. There are other motors that are pretty light that might work. Some to look up would be "cute hub motor", "heinzmann" ,"bafang", also "nine continent". Those are all pretty small hub motors that are light. Nine continent motors are a little bigger but they are like the standard e-bike motor these days and they have shown to be pretty good but they arent' as small as ezee, cute, bafang, or heinzmann. For battery, you can either go with LIPO which is the smallest batteries that you can get for e-bikes or you can go with LIFEPO4. I think they've improved LIPO these days and they aren't quite as dangerous as they used to be. You might be able to find an already built LIPO battery on an e-bike website. http://hightekbikes.com used to have LIPO batteries but I'm not sure that they still do. Also, http://itselectric.ca has LIPO batteries that are pre-built (they have a USA store as well...just choose USA at the main page).