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Discussion Starter #1
is it true that if you lower the bike, it dosent effect the handeling, but if you streach it it effects the handeling dramaticaly.
 

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"streaching" a bike does effect handling because it changes the wheel base and weight balance, shorter wheelbase = better turns. lowering it will also affect but, not as much as streching it/
 

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that's why the busa's aren't (imho) good twisties bikes because their wheelbase is so much longer. Longer wheelbase will keep the front wheel on the ground from what I'm told, but you sacrifice cornering ability. but I'd rather have a bike that can corner good than have straight line launch speed, that's just my opinion.

strat
 

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lowering you bike will fuck up your handling. same as stretching it. N e thing that changes the geometry of the bike will fuck up the handling. Think of the 2 wheels as pivot points of a lever or something. Whats easier to move the lever, grabbing it at the bottom, right by the pivot, or at the top, far away from the pivot? The further away from the pivot the easier it will be to move.

If you wanna adj the height of the bike, lower the front and raise the back, and then buy a steering stablizer
 

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Burton's right; lowering changes the rake/trail geometry, which affects turn-in and stability. Stretching also changes the handling, in a slightly different (but significant) way...
 

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Yeah, I had the unfortunate opportunity (read: pseudo-required by a cop...long story) to ride a lowered CBR 954. They normally ride kind of sluggish to begin with (smooth turn-in, but zero flickability...you have to haul it up from a corner), and it was just a mess...I hated it after thirty seconds, but had to ride it several miles. I was hating life.

Just for people wondering...rake is the angle of the steering column from vertical in degrees, and trail is the distance from a plumbline dropped from the steering head to a plumbline dropped from the front axle (sortof...easiest way to explain it). They're both related to eachother. If you lower the bike on a motorcycle without an adjustible steering head without properly compensating with other aspects of steering geometry, you're basically killing your stability at lean, as well as making it otherwise handle like piss (and killing your ground clearance, which can cause bottoming at lean, and possibly a very quick lowside).

Streching the bike just makes it turn in like penis. And you have to hold a higher lean angle to have the same turning radius as a non-streched bike at a lesser lean.
 

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i had mine lowered 1 1/4 inches front and rear for over a year and didn't have any problems. not saying it doesn't change anything. just that it didn't affect my riding. raised it back up cause of scraping the belly some.
 

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I don't believe that steering geometry changes if you lower the front and rear the same amount. Certainly just dropping the front will make the bike turn quicker, perhaps to the point of being unstable. Aside from losing cornering clearance, I don't think it'd be a huge change and the lower COG might actually help (until the pegs grind).

Extending the wheelbase will make the bike turn slower.
 

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If you can lower the bike the exact same percentage front to rear then now the rake/trail will not change at all. Rake is measure in degrees adn trail in inches. If you only lower the front by lifting the forks up in the triples and do nothing to the rear then you have shortened the trail and increased the rake which will make the bike twitchy, more prone to headshake and have alot faster turn in.

The shorter the wheel base the quicker and tigher turning radius the bike can execute but at a loss of striaght line stability. Exact opposite is true for longer wheel base, gives you better straight line stability at the expense of harder to get the bike to turn a tighter radius.

If anyone thinks a Busa cant turn I will gladly bet you $50 they can and that one of the local riders here in OKC will school your ass on the track at Hallett. Track record is 1:17, most fast track day riders are in the upper 27's and this guy was turning mid 35's on his busa.
 

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sneakyws6 and garry -->
The rake stays the same when lowered the same front and rear. The trail, however decreases. Here's a (ghetto) diagram.



Dropping just the front actually decreases rake and trail. Lowering the rear with it keeps the rake steady, but the trail will decrease just because you're bringing the steering head forward as you bring it down...remember the forks aren't completely vertical. Granted, just lowering it in the front kills your trail more, and also kills your rake...but you do lose trail no matter what.
 

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Originally posted by dragknt
sneakyws6 and garry -->
The rake stays the same when lowered the same front and rear. The trail, however decreases. Here's a (ghetto) diagram.



Dropping just the front actually decreases rake and trail. Lowering the rear with it keeps the rake steady, but the trail will decrease just because you're bringing the steering head forward as you bring it down...remember the forks aren't completely vertical. Granted, just lowering it in the front kills your trail more, and also kills your rake...but you do lose trail no matter what.
Good thing we're grading you on facts and not artwork.[:p]

However I thought trail was the distance between where a line extending from the forks intersects the ground and the contact patch of the tire. Someone correct me if I'm wrong.

Either way, you still lose trail with lowering a bike and it will affect your handling to some extent.
 

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Discussion Starter #14
OK, im really confused, so by lowering the bike, the turn radius will change causing the bike to turn quicker.

but extending the bike 6" will make the bike slower in the turns?

so if i lower and streach a bike, it will not be any different in turns because both extending the swing arm and lowering the bike will cancel each other out?

but the bike will scrape, and not be able to make such sharp turns in the twisties?
 

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Ok, let me try and straighten this out. If you lower the front only the bike will turn quicker and also be less stable. If you lower the back only the bike will turn like a pig. If you lower (lowering the front and back equally) and stretch the bike its still going to turn a lot slower than you're used to due to the longer wheelbase. And yes, the bike will have much less ground clearance for both turning (shit will start dragging, i.e. footpegs, shifter, brake lever) and bumps and won't turn as sharp in the twisties.
 

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shit if you change tires from OEM to something with a different profile your suppose to adjust the suspension to fix the geometry
 

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Originally posted by 6RracerMP
Mad Mike, you are correct, trail is the distance between where a line extending from the forks (same angle as forks) hits the ground, and if you drop a plumbline from the front axle.
+1 my bad, I was having a brain fart. :/
 

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Originally posted by Mad Mike

Good thing we're grading you on facts and not artwork.[:p]
lol...next time I'll use Paint. :D
 

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Discussion Starter #19
so then, what are some more things i can do to make the bike better in the twisties? i already have had the suspension tuned profesionally. now i guess ill just leave the bike alone.
 
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