Handling gurus check in-raising/lowering

[Shibumi]

Since I'm vertically challenged (5'8") I lowered my bike about 5 minutes after I bought it. As I've ridden it more and more in the last 3 months I've gotten more comfortable with twisties and am rapidly becoming a fan!

Inspired by GPW's Thor and Ronin makeovers I notice each featured +1 dogbones to increase turn in and cornering proficiency.
So my question is, does lowering the front and putting the back at stock height accomplish the same thing? I'm not up on the various geometric parameters involved but if I can improve handling and still reach the ground I would like to do so. I have Pingel lowering bushings on the front that drop it 1" and if I get a Tobin seat and reinstall the stock dogbones I am back at stock height in the rear but can still back the bike up without looking like a 12 year old.

I figure I'm already 20 lbs less than Nicky Hayden, if one day I can afford to buy all that high-dollar unsprung weight saving hardware I'm going to be close to fighting weight of Gixxers as far as corner-carving!

Someone please educate me on optimum geometry for cornering and whether lowering front improves such.

 

[ks-waterbug]

IMOP negative..... By raising the rear of the bike you shorten the effective wheelbase this in turn allows for the increase in turning. Lower the front has no effect on the wheelbase, but will impact the bikes handling characteristics ever so slightly. Unfortunately not in a good way for tight turns. Your cutting into the ground clearance afforded from the factory which can take away from the suspensions ability to handle the rough stuff. But on the plus side only the best of riders will notice this trade and on the street it can be less of a problem. Timed on a track is another story..



<!--EDIT|ks-waterbug
Reason for Edit: None given...|1156806367 -->

 

[Shibumi]

Thanks for the input! I don't ride hard on rough stuff, so don't think reduced ground clearance will be an issue. I still have a lot of suspension stiffness to play with up front and not a lot of weight to affect it.
So will raising the rear back up and leaving the front lowered improve handling?

 

[bigoltool]

You ought to check in with GPW and Sage Ronin. I think they put the +1 links on the back and then lowered the front 5mm if memory serves. This would have a pronounced effect on steering head angle and subsequently turn in.

 

[GPW]

I can tell you from experience. I slammed on my front brakes so hard coming down from speed for a tight turn at stock suspension, stock height on the front and cracked my front fender on both sides. My horn did actually thats how far the suspension collapse. This was of course as I was getting the suspension dialed in, it was way too soft. Dropping the front creates that issue and more with the stock suspension. Not an issue if you don't ride very aggressive in the turns. Just FYI. After upgrading the front forks and going 12MM up on the rear no issues again.



<!--EDIT|GPW
Reason for Edit: None given...|1156813926 -->

 

[GPW]

see the crack...

 

[BA BUSA]

Raising the rear and or lowering the front does not effect the wheel base

Raise the rear 1" with the shorter dog bones and lower the front up to a 1/2"

 

[Churchkey]

My rule of thumb: Lowering the front makes the bike turn in faster/quicker. Raising the rear has a similar effect but to a lesser degree. Raising the rear 1" will give you about the same turn in as lowering the front 1/2".

Lowering the rear only will make it head heavy & will require more steering input to get it around a corner.

 

[camaroguy72]

im raised 1" in back, lowered 1" in front. sick

 

[ks-waterbug]

Raising the rear and or lowering the front does not effect the wheel base

Raise the rear 1" with the shorter dog bones and lower the front up to a 1/2"

Wheel Base..
Oooops typo; you are correct I meant will make the Busa FEEL as if the wheelbase has been shortened! The only way to change the actual wheelbase is to move the axle to the fwd most position or change the gearing and of course install different swingarm.

Raising/Lowering Front
"There are two basic ways to alter a sportbike's chassis geometry. The first is moving the fork tubes up or down within the triple clamps, which alters front ride height and overall geometry. Bring the fork tubes upward in the clamps and you'll reduce rake and trail—quickening steering—as well as overall ride height. Dropping the front may make cornering clearance an issue, and you shouldn't lower it so far that the front wheel contacts the engine, exhaust system or radiator at full compression. (That was the screeching noise you heard just before the crash.)"... Motorcyclist Mag


Some suggestions on how to set-up
6 step process
Sport Rider Settings

 

[Red05]

The only way to change the actual wheelbase is to move the axle to the fwd most position or change the gearing and of course install different swingarm.

That's why besides raising the back 1", the 42T rear sprocket ranks right up there with my favorite mods. Besides the extra acceleration down low, the bigger sprocket causes the chain to "suck in" the rear wheel, in effect shortening the wheelbase about ½".