Alternator

[Vatch]

How many extra Watts, if any, are available from the alternators on these bikes (79 US model specifically). As part of the "bringing the bike up to daily useable standards effort 2006" I am considering a number of improvements including heated handgrips. I have them on my Kawasaki (on the chopping block?) and will want them on the CB if the Kawasaki goes.

A few considerations: I would only be using the heated grips during cool weather rides over 30 minutes (the time it takes for my hand to be numb at 5 deg. C). Most likely such trips would involve some sustained higher speed travel, so RPMs should consistently be over 5000. The heated grips on my Kawasaki have two settings: 15W and 30W. 30W is usually too much heat unless I am riding at 0C on the highway for many hours at which time some other part of my body goes numb. 15W is most likely too much for the CB, but perhaps some lower amount, 10W or 7W?

[Ibsen]

If the charging system is healthy it shouldn't be be any problem using the 15W grips. The alternator puts out 260W at 5000rpm.

[Vatch]

260W?! I am shocked, yet pleased.

How much would be used to charge the battery (I know I read this on here before)? Add that to the various running lights and I should have a total W use by the bike. I am sure I would be well under 260W.

[Volker_P]

Battery charging depends on charging voltage and battery voltage which reflects the actual charging state. If your battery is fully charged, the alternator is not occupied with charging the battery.
On the other hand, when the battery is not full and many users want to have electric power, the charging voltage will go down. This means your lights and so on will work fine, but the battery will be charged very slowly. This may result in starting probs in a short trip period. In the worst case of power consumption being above alternator power you will suck your battery empty with time until voltage is too low for ignition and your engine will stop.
For any ugrade, consider to use cables and fuses of sufficient dimensions to avoid problems and unnecessary loss powers.
Original switches may be overloaded easily by additional loads, so using a relay is often a good option, especially for heating purposes.

[Ibsen]

I believe most grips require a 5Amp fuse:

http://www.hotgrips.com/trouble.html

http://www.hotgrips.com/ergo_401_installation.htm

http://www.hotgrips.com/vhc-inst.html

A friend of mine installed heated grips on a Kawasaki KZ400 with a 210W generator, and they work fine without any problem.

[DammitDan]

Can you feel the heat through your super thick riding gloves though?

Heated grips seem a lot less useful than say, a heated seat would be.

[Volker_P]

Heated grips seem a lot less useful than say, a heated seat would be.

A heated seat may be more effective from heat transfer considerations but basically I prefer to have heated the parts where it is really cold and problematic during riding. However you are right, heated grips are not very effective if you do not have some additional windshield for your hands. This way you do not need that much thick gloves which provides better feeling and handling and also better heat transfer from the grips.
With a hand protection windshield and very warm clothing (like a thermo suit), you can even save the heated grips.

[Ibsen]

I agree with Volker. I have never had a cold ass when I have been out riding, but my hands have been cold more than once.

[nickjtc]

I had heated grips on the KLR650 I once had, which I believe had a lower power output from the alternator. If that system could support the power drain I'm sure the 650's will too. And I'm putting heated grips on Sophie, too.

[Vatch]

You feel cold first in your extremities. So heating your hands is really a comfort issue. If your ass is getting cold your core body temperature may be dropping at which time you might want to find a place to warm up.

Thanks for the replies.

[Volker_P]

So heating your hands is really a comfort issue. If your ass is getting cold your core body temperature may be dropping at which time you might want to find a place to warm up.

I don't think it is just comfort. To have feeling in your hands is essential to stay upside, especially when the roads are wet. From my experience I can't use the front brake safely any more before I worry about my ass getting cold.
I would say just the other way round: Riding with a cold ass is a question of comfort, but riding with cold hands is dangerous. If you are susceptible to catch a cold, you may see this point different of course.

[bandwidth69]

Im in agreement with the postings here. I wouldn't bother with heated grips myself, but that's because In the winter, when i do ride, it isnt very far anyway. I have had the experience however of falling off a bike - through cold and fatigue. Not nice. Winter, yes - tried to ride around the outside lane as usual - but I'd become so stiff that I couldn't bank the bike hard enough into the oncoming corner. I lost my balance and the bike went from under me. This was several years ago while on my Yamaha RD 125LC. The cold had got to me after about five hours into the journey. This is despite regular stops and enough layers of clothing to open my own department store! It still wasn't enough. I think clothing has been covered in a previous post. My personal rule of thumb is that two is always better than one. Better to double up on thinner items underneath your biking gear. Rather than wear one thick sweater, I wear two thinner ones. Oh - hands and feet are the danger points when riding on these "naked" CB 650's as are, for me at least, my legs - especially the thigh area. Again I just double or tripple up on the layers. This works for gloves too. A thinner linning glove inside your riding gloves are best for me. But you have to get the right fitting glove. Two small and your fingers will be pushed to the outside layers of the glove - not good as you never feel the benefit of any insulation they may have. Too thick and the opposite happens. You lose all feeling and connectivity with whatever you are riding. Its a tough one.

Anyone ever used a kidney belt? Or what about those bavaclava things? One of them might be on my Christmas list this year?

[Volker_P]

I agree with your layer theory. In all cases you have to leave enough space for an air layer, so close-fitting should be avoided (especially for the boots too many sock layers are bad).

A kidney belt avoids air being blown through the jacket (and looking like a parachute). Combined with a fur vest beneath the motorcycle jacket, it is quite useful to keep your body warm.

I have an open helmet, so a bavaclava is insufficient for me in winter. However I wear it beneath my thick arbian scarf (which may be not political correct, but works perfect for that application ) to cover the leaks in the scarf wrapping which can become unpleasant at higher speeds and low temperatures.

A thin rainsuit also provides a quite surprising warming effect just by keeping off direct air from your motorcycle wear. That's one reason to have it with me all the time.

After many years of questionable experiments, for winter riding I now have a thermosuit, which is basically a rainsuit with a thick lining. It is just great. You get boiled when you wear it above +10°C.

[Guest]

I have an open helmet,

You are a brave fellow, Volker!!

[Ibsen]

Anyone ever used a kidney belt? Or what about those bavaclava things? One of them might be on my Christmas list this year?

I have used a kidney belt for 10 years. But it is the elastic type and I wear it under my jacket. I never ride without it.
I also use a balaklava in cold weather. It makes a big differnece.