As I get get into colder places the Bonneville's alternator is starting to be a limiting factor. Would anyone happen to know a UK supplier who could rewind a modern stator for higher output? I can find plenty of places that can give classic bikes enough power to run their headlights, but nowhere that can deal with a modern unit that combines the ignition parts.

Thanks

Andy

If you've searched around you've probably come across West Country Windings ( Westcountry Windings ) They've done a stator and three rotors for me over the years but I only wanted to fix broken originals, not to upgrade anything.

I haven't used them so can't offer a recommendation but Electrical parts for motorcycles - regulator rectifiers generators stators ignition coils lighting coils ht & pulse coils cdi units starter motors rotors might be able to sort you out

I've bought a few reg/recs from them for my classic bikes and as they're not far from me I"ve gone over to collect from their factory. Really helpful company and probably the place to buy std replacements but I don't think they do specials - it's more of a factory production line than a guy in a shed.

Probably a bit extreme for what you're after, but my mate mouse uses a car alternator to get high power output.

He's done this on two different bikes, both times using a belt to drive the alternator (though I think he originally experimented with a chaindrive with poor results). On his bmw he just welded a pully onto the rotor, and on the other bike (a gsx550) I think he extended the crank somehow through the sidecasing.

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UK to Mongolia 2009, on a DR350

Andy,I know it's not really what you are looking for but how about adding an extra battery in the chair?I realise that it is only posponing the inevitable,it will obviously discharge eventually if you use it enough.Can I ask what you are looking to power with the higher output alternator?

Many thanks for the useful links.

I already have an 85 AH battery in the chair, but it doesn't solve the basic issue that 27A output drops to under 20 at low temperatures, the battery loosing capacity as it cools in addition. 240W soon goes in heated jacket, visor, grips, headlight, GPS etc. and simply can't take the additional load of extra lights or a passengers heated kit if you want the starter motor next day (Oh why can't the Hinckley clowns fit a kickstart to RETRO bikes!). I calculate that I need to ration electrical power at anything under minus 10 if I want to remain independent for more than a few days. Ten minutes use of the tyre compressor means no heated jacket for an hour, which starts to get annoying and a sump heater would be a useful addition for the far north but would cut the heat ration further still.

(I carry chemical heat packs as a back up and substitute for the heated jackets 55W, which you can recharge on a camping stove, but of course you can only carry so many)

The pulley idea doesn't strike me as entirely practical as the alternator is on the right so the shaft would need to pass through the structure of the bike or the alternator would stick out from the motor. This is where BMW's and Urals are great, you just bung on a 70A VW job then work out where you'll keep the displaced petrol and CD changer! I don't really want a shaft passing out on the clutch side as this means oil seals. The sidecar wheel is another place to mount a pulley, but two alternators and two VR's gets messy.

One alternative would seem to be to mount a second standard rotor and coil and make a spacer for the cover, but I'm hopeful a simple rewind or new stator will boost the output by 10-25% which would be enough of a safety margin even at minus 20 but wouldn't rob too much power from the engine.

As a rather weird sideline, a solar panel is useful addition, adds about 5 AH a day even on a day like today.

Andy

I don't know how modular Triumphs are these days.When I had my Trophy pretty much everything would fit most every other model they made.Is there a higher output alternator on another Triumph that you could use?
Can you shave anything off your consumption by using LED lights for example?
Failing that,an even bigger battery in the chair or an extra solar panel?

With the BMW's airheads both of the larger capacity aftermarket alternators are larger than the stock one. But they are under the front cover and have the room.
Any aftermarket or rewound alternator will have to have a bigger gauge wire and a larger rotor and or stator.
Any extra watts, amps requires a bigger alternator.
If you can find the room for a larger alternator in the Bonneville I would think it could be done.

The stator is mounted inside the crank cover so there is room for a slightly bigger one. The rotor doubles as the ignition trigger so I am wary of messing with it.

The parts catalogue is definately something I'll try, it's just a case of sifting through the obvious choices to see if any part numbers match. The devious whatsits at the factory usually give the same part as many numbers as they have models, but the aftermarket suppliers usually can't be bothered.

Thanks Gents,

Andy

How about mounting a wind driven small car or alternative energy alternator in a turbine funnel mounted on the sidecar?

As you have a sidecar [and therefore lots of room], why not take along a small engine driven generator of 800 to 1000watts ?
It will be useful when in camp ,can recharge your bike battery ,provide lights and be a back up generator when at home .

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Blessed are the cracked, for they let in the light. - Spike Milligan
"When you come to a fork in the road ,take it ! When you come to a spoon in the road ,take that also ."

Taking power out of the slipstream is possible and I've done some calcs on how big a propeller you'd need, but unless you are an airliner gliding at 200 mph you seem to get less power than a solar panel.

A nice Honda suitcase in the chair is possible but they weigh about 15kg and cost a lot.

Both ideas have the second power source issue. I'm not far enough into this to work it out, but I'm thinking a second source over a few Watts will upset the VR?

Good ideas though.

Andy

I dont think it would bother the VR as it would see charge from the other generator as simply a rising voltage and would back off as if the battery was charged.
The simplest way would be to isolate the sidecar battery with a switch as is done in camper vans. Then use the bikes alternator for the bikes requirements and use the wind driven charger for the side car battery and heated clothing. My thinking is that at bike speeds you can get away with smaller diameter fan than normal. using a permanent magnet generator.

Here's some things you can try. First of all, you need a good volt meter that you can moniter your power use. Knowing when your killing your battery may save you a lot of walking. Here's an example:
DigitalMeter.com - Digital Panel Meters manufactured by DATEL
Clean up your wiring! Grease all your fittings with di-electric grease after you've sprayed and scrubbed them with contact cleaner. Most important are your grounds. Replace any old wiring thats corroded with marine grade wire.
Following the green revolution, it's time to look at being more efficient. HID head light kits reduce your lighting power consumption a great deal, plus you get WAY more light.
FutureVision HID - The Future of Performance Lighting Systems
Finally, research how your stator is wound. I recently changed my stator on my DR650 from Wye to Delta configuration, adding nearly 70 watts! you can read about it here:
- ProCycle
And there's a great deal of information here:
Stators demystified - ADVrider
Hope this helps.
BTW, i just heard on the news your Canadian-like weather, poor bastards! Bundle up and take care out there!