Just a bit of info for anyone who's thinking about a 5 series. There's a lot of info on the net, some of which is contradictory, so maybe this will help.
I started off with a Clyte 409 kit running on a 4820 controller and a Crystalyte Lithium 38v 9A battery. Despite all the talk of torque it's prettty anaemic in Malta which is all hills. I was looking for a motorbike substitute and this wasn't it.
After looking around I thought I'd go for a bigger battery and motor. Thanks tothis site, it became clear that a bigger batter and controller using the 409 hub would not be such a good idea (glue melting and magnets falling off when using high current) so the 5 series 5304 which was said to have a good combination of spped and torque was clearly the way to go.
I got a bit confused a few times as (for instance) one importer's website stated that there isn't too much difference between the 4 series and the 5 series on a bicycle seeing that a 4 series is much lighter and can achieve similar top speeds. Well to anyone else who read that, please note that this statement is complete bollocks!
The 5 series rear motor slipped between the rear dropouts easily - I had to place a spacer between the 7 speed gear cluster and the dropout as the two were pressing against each other once I tightened the bolts. A bit of swearing there as I had to dismantle everything.
I chose a 48v 35Amp controller to go with the 48v 20Ah Ping battery (Ping is one of the most helpful sellers you'll ever come across - a genuine nice guy).
Anyway, end result is fantastic and I can't see myself needing anything else. I have no felf the need to peddle up hills including some pretty long and steep one (compare this to a 4 series hub which runs out of steam as soon as a little hill can be seen). The bike actually picks up speed going uphill even though it uses 26" wheels! 50kph on a flat is easily achievable. It's basically what I wanted - a small motorbike.
Highly recommended setup.
11/16/2008 - 1st Long Ride (~5miles): Stable, smooth performance. About 23-24mph on flats. Very quiet. Some cogging at startup, but soon goes away. Some vibration up the steepest hills without pedaling. Pedal-first controller is smooth and kicks in about 3mph or less. May opt for the "shunt mod" in the future to double the current (40A). Bike uses a shimano internal hub shifter, which is a great match to the hub motor: very easy shifting. Highest gear is just barely acceptable for pedal assist on the flats & downhill. May opt to up the "front ring" of the bike for higher gearing...
- bike: ready for a MN winter
- my brushless rig
Development Background: Bought bike from Craigslist. Came with 400W BL-36 and no battery. Wanted to go to 48V, and quickly found out that the controller was only rated at 50V (50V caps). Bought C7220PF controller from ebikes.ca. Bought Ping 48V 16Ah V2 battery on ebay...
- pre assembly
Forks are welded aluminum, appear very strong, but still wanted a torque arm for safety. Ampedbikes seems to have a killer product...
- ampedbikes torque arm
- stealth ping battery & clyte controller