Lower CG for Better Handling


Trialsman

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Watching the battery removal video brought back another idea I had for quite a while. I always wondered why so much room was given below the battery (obviously protection). This raises the center of gravity and alters handling characteristics. If the cables are long enough would it not be possible to make new battery mount brackets to lower the battery in the frame and improve the handling from its current location? I used to modify my enduro bikes by lowering the engine cradle, dropping the weight of the engine, which really improved the handling and felt weight but at the cost of ground clearance. Usually the range of drop was somewhere between 1" to 2". With the very wide gap below the battery you could gain maximum effect with no decrease in ground clearance. Seems like a win win if the cables are long enough and there is not some other reason that is eluding me. It would be very important to run a skid plate but that was the first thing I built anyway both in aluminum and carbon/Kevlar. Let me know your thoughts. I might be way off base but I never let that stop me before.
 

Trialsman

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A secondary thought is that it may also aid in cooling since you are dropping it into the airstream a little more and separating it from other heat producing components above the battery. You may get better air flow over the battery as well.
 

snydes

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There might be enough slack in the connections for an inch or so.

Should be a relatively harmless thing to try. I say go for it. Nothing comes to mind why it wouldn’t work.
 

Fod

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I'm not seeing how the air flow is better if lower. Please enlighten me!
 

Trialsman

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It just seems like more of the ribbed section of the battery would be out from under the frame for more air flow but the biggest might be the airflow you might pick up over the top. Thanks Steve for the info on the cable slack, I probably will play around with it when I get the time. Let me know if anyone sees a major drawback or problem with the thought process. By the way they handle very well but, from the past, lowering the CG really helps and could make it even better.
 

Philip

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Actually, a bike with a higher CG handles better than a bike with a lower CG. This is because the front wheel has a longer lever to initiate the turn and to lean the bike. A supermoto bike would outhandle any other bike on a tight asphalt course.

However, for slippery surfaces, a bike with a lower CG is preferred. It is easier to keep a sliding bike upright by weight shifting and foot-dragging. The rider has a longer lever to lift the bike if it starts sliding. This is why dirt tracker bikes are low. Helps keep the front wheel down too.

If the available suspension travel was not a consideration, I am not quite sure which type of a bike you'd prefer for motocross ruts, bermed corners, and for flowing woods trails.
 

Trialsman

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My background is deep woods and enduro type riding. If I ever went off a triple it would be totally a screw up on my part !! I want to ride the bike for five days straight in GA first week in April before I play with anything on battery relocation. Looks like it will be pretty simple to fabricate a bracket set and the cable leads look from the top to have pleanty of room. I will probably experiment with it when I can get a back to back comparison and I will let you know how it goes. I will post templates of the brackets if anyone else is so inclined. One question though.....What components are in the lowest portion of the pack - the black section? How closely are they fit to the lower front edge as that will be the limiting factor?
 

Philip

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One question though.....What components are in the lowest portion of the pack - the black section? How closely are they fit to the lower front edge as that will be the limiting factor?
The lowest battery module sticks out about 1" below the bottom of the aluminum part of the battery housing. The stuff below it is a desiccant pack and empty space. If you ask me, the lower battery cover could have been made much smaller.
 

Tuner

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Lower CG does not always = better handling. Weight transfer and leverage are important attributes regarding overall performance.
Sometimes more = too much.

Regarding seat height..... I have lowered numerous Alta's via suspension with very positive results.
2" inches front and rear has proven to be the best overall compromise.
 

leeo45

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Lower CG does not always = better handling. Weight transfer and leverage are important attributes regarding overall performance.
Sometimes more = too much.

Honda certainly discovered or realized this with their 500cc GP bikes a few decades ago. They moved the gas tank to the bottom of the frame and the bike wouldn't turn.

(and yes, I understand that the dynamics of turning a roadracing bike or a street bike at speed can be quite different from turning a MX or enduro bike on a low traction surface, however many of the factors are the same)
 

F451

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Honda certainly discovered or realized this with their 500cc GP bikes a few decades ago. They moved the gas tank to the bottom of the frame and the bike wouldn't turn.

(and yes, I understand that the dynamics of turning a roadracing bike or a street bike at speed can be quite different from turning a MX or enduro bike on a low traction surface, however many of the factors are the same)

I remember that and was going to comment. The lesson I took from it is that chassis & suspension tuning for optimum handling and performance is not always as simple as it might seem. Lower COG in general sounds like a good thing, in practice, may or may not be a benefit. These companies are spending small fortunes to get the slightest advantage, sometimes the changes don't work out.

And not trying to discourage the OP from making whatever mods, experimentation is all good, we will all learn something from it one way or the other.

Personally, I would like the lower frame rails raised up along with the footpegs, but will be leaving my bike's frame stock as I'm no fabricator and will just live with it.
 

Rix

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Actually, a bike with a higher CG handles better than a bike with a lower CG. This is because the front wheel has a longer lever to initiate the turn and to lean the bike. A supermoto bike would outhandle any other bike on a tight asphalt course.

However, for slippery surfaces, a bike with a lower CG is preferred. It is easier to keep a sliding bike upright by weight shifting and foot-dragging. The rider has a longer lever to lift the bike if it starts sliding. This is why dirt tracker bikes are low. Helps keep the front wheel down too.

If the available suspension travel was not a consideration, I am not quite sure which type of a bike you'd prefer for motocross ruts, bermed corners, and for flowing woods trails.
That sounds very scientific and $h!t. There is truth to this though. when I laced a 17"Mc wheel on to my Bomber, the rear dropped a full inch over the stock 24"MTB wheel with the 3.00x24" Duro Razorback, which would be the equivalent of a 20" front MC wheel. With the lower center gravity, it threw off the handling on slight off camber terrain.
 

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