Author Topic: Battery relocation and balance/handling (Read 2066 times)

jessezm · « **on:** August 16, 2010, 08:48:07 AM »

Question for the gang:

I'm at the point of making final decisions on where to locate my battery and electrics on my CB400f cafe bike. I've got plenty of room under the seat cowl for everything, and was going for that nice, clean "triangle" look. But does anyone have any experience with the added weight over the rear wheel affecting handling at all? Even with a modern battery, it seems like a significant amount of weight added. The other alternative would be locating the battery in front of the rear tire by welding on some sort of bracket. Are there any compelling reasons other than aesthetics for where to locate the battery at this point?

jessezm · « **Reply #1 on:** August 17, 2010, 06:04:44 AM »

Anyone?

flybox1 · « **Reply #2 on:** August 17, 2010, 07:16:42 AM »

i'm guessing if you've upgraded all of your suspension components, front and rear, and you've been staying away from the 1/2 lb double bacon cheeses for the past year, its not going to make much handling difference

put i where it looks nicest and ride.

nokrome · « **Reply #3 on:** August 17, 2010, 07:21:29 AM »

in theory the lower you mount your battery the better your bike will handle (lower center of gravity),
having said that i can tell you that i have my battery under my seat cowl and my bike handles great.
maybe it would matter if you were racing everyday but for regular riding i dont think that you will ever feel the difference

jessezm · « **Reply #4 on:** August 17, 2010, 07:27:43 AM »

Cool. I'm in pretty good shape if I do say so... 164lbs at 5'11." However, the front suspension is stock, just rebuilt with new fork seals and fluid. The rear shocks are Redwings, though, and honestly, even in the highest position they feel pretty soft. I may have to upgrade both front and rear suspension if I do any serious riding, but I haven't had this bike on the road yet. Sitting still, the bike feels super light (although that's without oil, fuel in the tank or the carbs and battery installed). The Roccity Cafe tank and seat are WAY lighter than the stock, and I've removed the center stand and stock footpegs. A welder friend is coming over today to look at what we need to do.

boulder74 · « **Reply #5 on:** August 17, 2010, 07:57:31 AM »

So are you doing pods or a modified airbox? I just got the Roc City seat and it's sweet, took a little thinking to get a good mount on my 500 but it's on and looking good now. Taking it to paint today

jessezm · « **Reply #6 on:** August 17, 2010, 08:04:09 AM »

I'm going to attempt pods--I have K&Ns. But I have kept the airbox and manifold just in case. Wish it wasn't so ugly!

My starting point for jetting, with a 466cc big-bore, aftermarket slip on with kerker 2" baffle, and mild cam from Webcam, is:

Needle--one position richer from stock
Pilots--38 (stock is 40--this was a suggestion from Rick Denoon)
Mains--90 (stock is 75)
air screws--1.75 turns?

We'll see where I need to go from there...

MCRider · « **Reply #7 on:** August 17, 2010, 09:31:00 AM »

Generally speaking performance bike builders look to put the weight in a triangle defined by the axles and the shoulder of the rider, more or less. The further away from that triangle you get the worse it is. And 10 lbs at the far reaches (seat cowl) is 20 lbs inside the triangle, again, in generalities.

Hence monoshock frames, Which puts the shock in the triangle, calipers on the rear of fork legs, things like that.

It would also contribute to terminal wheelies, if that were a problem.

But as has been stated, if you're not setting up for 50%+ track days/50% street, do it however you want.

Skunk Stripe · « **Reply #8 on:** August 17, 2010, 12:52:36 PM »

How much room do you have right above the swing arm, between the tire and engine/frame? You could get a thinner battery and mount it in the area with a thin battery box to protect it. Then you lower your weight while staying in the metaphorical triangle. If you don't have to sit in a lot of traffic, you could get a small amp battery to save weight.

jessezm · « **Reply #9 on:** August 17, 2010, 12:59:01 PM »

Quote from: Skunk Stripe on August 17, 2010, 12:52:36 PM

How much room do you have right above the swing arm, between the tire and engine/frame? You could get a thinner battery and mount it in the area with a thin battery box to protect it. Then you lower your weight while staying in the metaphorical triangle. If you don't have to sit in a lot of traffic, you could get a small amp battery to save weight.

There's actually a lot of room there, and I'm not sure it would be too obtrusive. Because I don't have a kickstarter, though, I want to keep a relatively decent battery. But the AGM battery I have now is pretty small as it is, it's just dense (heavy!)

Skunk Stripe · « **Reply #10 on:** August 17, 2010, 01:20:08 PM »

AGMs are a little heavier but much greater Cranking amps. good batteries.

jessezm · « **Reply #11 on:** August 17, 2010, 02:05:47 PM »

Cool, thanks everyone, I think that's what I'll be doing!

Skunk Stripe · « **Reply #12 on:** August 17, 2010, 02:30:43 PM »

Just remember, an agm can be mounted in any position. Even upside down.

Gcolgett · « **Reply #13 on:** August 17, 2010, 02:42:08 PM »

Hi Jesse: the e mail you sent was corrupt so can you send me a picture of the rear fender and a picture of the turn signals thanks George

jessezm · « **Reply #14 on:** August 17, 2010, 04:12:49 PM »

Dang, sorry--maybe it was too big, let me try one pic at a time...

kayaker43 · « **Reply #15 on:** August 17, 2010, 05:00:13 PM »

You might consider the new Lithium batteries. You should be able to use one of the 4.6AH 8 cell packs that weighs 1.6 lbs. That's a whopping 7.3 lbs less weight so placement is hardly an issue and they are much smaller too. Don't compare the AH ratings, they have more usable voltage curves the lead acid and can be 25-30% of the size.

I'm guessing even the tiny 2.3 AH batteries will do just fine and they only weigh .8 lb. The small one will actually start a car so cranking isn't the problem. The limiting factor is that you can only charge them at 10 amps and I'm not sure what the charging output is on the 400? The 8cell pack can absorb 20 amps.

Heres some pics,.. more info here http://www.build-stuff.com/x-cell.htm

Skunk Stripe · « **Reply #16 on:** August 17, 2010, 06:21:57 PM »

I think the issue is more with capacity than starting. Heck, you should be able to start with a 1 second push of the starter in most weather.
Some people have issues with extended running without charging or in stop and go traffic. I dont think I would go too low on capacity. I know a 750 is ok with 7Ah. Just my 2c.

jessezm · « **Reply #17 on:** August 17, 2010, 06:28:18 PM »

Yeah, I have looked at those batteries and I actually may do that at some point. My two concerns were price and capacity. With my dyna s ignition and 5 ohm coils I'll be pushing the charging system capacity already on my 400, especially given that I'll probably be doing mostly around town riding. so much so that i'm already thinking of an easy way to plug in at night without having to take out the battery. I might be being a little paranoid, we'll see...

Skunk Stripe · « **Reply #18 on:** August 17, 2010, 07:11:24 PM »

If you want to offset that some, switch your signal, brake, and indicator lights to led. Save a fair amount there.

kayaker43 · « **Reply #19 on:** August 17, 2010, 10:30:48 PM »

Yeah, use LED's wherever possible and you should be fine. The big question is whether you get some charge at idle, and how much time you spend there? As soon as the revs come up a little you're good.

The coils aren't that big of a draw. The flip side of a small battery is that it charges much faster too.

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Author Topic: Battery relocation and balance/handling (Read 2066 times)