I appreciate the Walkernator as being a very serviceable solution, albeit some what large and bulky.
I went at it a little more discreetly.
The alternator is a permanent magnet from a small John Deere tractor. It pivots on the through bolt for the footrests (the hole needed to be drilled out slightly and the battery tray mount shortened, I recall I made anew one) and the outer end is held by an automotive style slotted arm pivoting from the original generator hold down clamp. The jack shaft is a two piece part held together with a draw bolt in the outer end and suspended between two bearings, one in the opening which already exists and the other in a solid outer cover. As this seals up the primary I have a small breather fitted to the inspection cap. The pulleys are J section 6 rib poly V belt. The largest I could fit on the jack shaft and the smallest I could fit on the alternator. It has been running since 1992. It has had two major issues. Once due to pilot error - the screws holding the sprocket to the jack shaft were not installed correctly and even the lock wire couldn't hold them, This was on the original one piece jack shaft and disaster ensued. the other was that a wire fell off the regulator - twice. I run an 85W headlight and have switched most everything else to LED, and I also run a heated vest. It pretty much balances the load around 2K RPM.
These units come in 3 sizes...
200 watt units (which is what I have)
300 watt units are the same as mine but the regulator uses all three coil outputs. whilst mine only uses 2 of the three available.
400 watt units which use the 3 outputs and the alternator has stronger magnets.
I have run this for about 100K miles (yes 100,000 miles).
The belt drive has had the belt replaced once or twice and I carry a spare although it has never failed on the road. I don't crank it up too tight and it stakes the shock out of the permanent magnet system. I have never had it "eat" the rollers on the primary chain.
It was a bit of a PITA to make and install, but has been VERY reliable.
I went at it a little more discreetly.
The alternator is a permanent magnet from a small John Deere tractor. It pivots on the through bolt for the footrests (the hole needed to be drilled out slightly and the battery tray mount shortened, I recall I made anew one) and the outer end is held by an automotive style slotted arm pivoting from the original generator hold down clamp. The jack shaft is a two piece part held together with a draw bolt in the outer end and suspended between two bearings, one in the opening which already exists and the other in a solid outer cover. As this seals up the primary I have a small breather fitted to the inspection cap. The pulleys are J section 6 rib poly V belt. The largest I could fit on the jack shaft and the smallest I could fit on the alternator. It has been running since 1992. It has had two major issues. Once due to pilot error - the screws holding the sprocket to the jack shaft were not installed correctly and even the lock wire couldn't hold them, This was on the original one piece jack shaft and disaster ensued. the other was that a wire fell off the regulator - twice. I run an 85W headlight and have switched most everything else to LED, and I also run a heated vest. It pretty much balances the load around 2K RPM.
These units come in 3 sizes...
200 watt units (which is what I have)
300 watt units are the same as mine but the regulator uses all three coil outputs. whilst mine only uses 2 of the three available.
400 watt units which use the 3 outputs and the alternator has stronger magnets.
I have run this for about 100K miles (yes 100,000 miles).
The belt drive has had the belt replaced once or twice and I carry a spare although it has never failed on the road. I don't crank it up too tight and it stakes the shock out of the permanent magnet system. I have never had it "eat" the rollers on the primary chain.
It was a bit of a PITA to make and install, but has been VERY reliable.