WTF causes that?

Okay, here's the deal. Last night me and a couple of our other locals go out to a local parking lot to play "chase" and take some relatively low speed turns (circles, quick left and right, that kinda thing... 30+ in the "straights", 15+ in the turns). I have a couple of guys ride my bike around a bit, then they jump off mine and onto another 07 CBR600RR, and take off around again. All of them come back reporting the same issue... so I jump on his bike and take off to see. Sure enough... it's there.

My 07 CBR600RR likes to "stand up" in the turns. It's not like it won't lay down low... but I have to put significantly more effort into the bars to keep it low, which can make it feel a bit more twitchy if I hit mid-corner bumps.

My question is... what causes a bike to want to "stand up" (without using brakes of ANY kind). Suspension settings? Preload? Tires? Here's the info on the two bikes.

Lrn2Go's 07 CBR600RR [ul][*]Almost 13K miles[*]Running Metzeler Sportec M3's. [ul][*]7-8K on the front - Starting to notice squaring, but by no means the worst I've seen. Plenty of life in the tire.[*]4-5K on the rear - Minimal squaring, that I can tell.[*]Running basically "stock" psi in both tires (as recc. in the owners manual/swingarm)[/ul][*]Stock Suspension settings (haven't changed a stinking thing since I bought it)[ul][*]I weigh about 190lbs, 6'2"[*]I've thought for a while that I could probably use some more preload (if they're really set up for little 140lb guys).[/ul][*]Handling characteristics - [ul][*]Bike feels like it "bites" into the pavement in a high speed corner.[*]Also feels like you have to "muscle" it down past a certain point at all speeds... like it's "fighting" me and wants to stand back up.[*]All "solid" feelings can go out the window if the corner is bumpy becuase of the effort I'm putting through to the bars to keep countersteering. (had always assumed this was just my lack of ability/experience with very high lean-angle turns and that it was "supposed" to feel like that)
[/ul][/ul]Choppa's 07 CBR600RR [ul][*]About 2-3K miles[*]Running stock Bridgestone Battleaxe's[ul][*]2-3K miles on front and rear, minimal squaring both ends.[*]Think it's running stock psi in the tires[/ul][*]"Tweaked" suspension settings. Not sure what all his friend did, but mainly said he "Stiffened" the suspension a "little bit". [ul][*]No change to pre-load or specific "tooling-required" changes, IE not lowered or anything. [/ul][*]Handling characteristics - [ul][*]Bike is just as stable as mine in a line[*]"Lays" into a corner and "Stays there" with noticibly less effort, when ridden back to back... feels solid, maybe more "flickable".[*]Takes a bit more effort to "stand up" the bike coming out of the turn... could be because my bike feels like it wants to stand up on it's own.[/ul][/ul]So, CBRForumians... what do you think? I need your wisdom here. My bike is able to do anything I've asked of it (it's not like I push it though, 99% of the time), I can lay it down low, even flick it back and forth... but ridden back to back on the same model/year bike as another... his feels quite different, in a bad way. I'd like to get my bike to feel like it wants to turn. Help me out!

 

probably your tires.

 

I would have to say tyres too ... squaring will cause all sorts of unpredictable behaviour in the bends ... you are probably riding it on the edge of the square and it feels like it wants to tip back up ...

Jules

 

Maybe the stabilizers are adjusted differently?

 

I'd like more input, and if tires ends up being the case, I'd like to know why? (IE, what kind of logic is going on behind "tires"... the physics of the situation... or something.)

Choppa and SchiraF4I know what I said I thought the issue was and why it felt so different, but I'd like to hold off on my opinion here until I get some more collective input from the masses.

 

Stabilizers? You talking the Steering Dampner? (If you are, those aren't adjustable... both are the stock "electronic" ones that come with the bike... making adjustments on their own via the computer and your speed)

 

ok imagine your tyres are really square here ... you lean in to a bend and are riding on the "edge" of the square ... there is no support to the road towards the middle of the tyre that would be there normally if you had round tyres ..see?? ... this would effectively keep the bike over effortlessly ... it's kinda like your bike is trying to fall back onto the flattend part of the tyre .. square is bad ..it just is ..lol

Jules

 

Another thing ... if you are riding on the edge of the square then your tyre contact area is reduced just at a atime when you need it to be the greatest ... all sorts of strange handling goes on with square tyres ... I've ridden a few like this including my own once I'd squared them off ..

Jules

 

Since his suspension is adjusted differently that would be the biggest difference. the tires will make the bike feel different as they are worn, but the suspension is most likely the cause. (the softer setting that your has is most likely loading the components and transferring the load and weight distribution. I'd bet that if you stiffened the front a little and moved up a few clicks on the rear that the bike will feel much different. (the harder suspension will make the bike feel lighter in the turns and the softer will make the bike feel mushy, or heavy Also, how much fuel did each bike have in it? 20 or 30 pounds can make a bike feel a lot different)

 

Ok, wasn't sure if they were or not. I know they come stock with the HSOD elec damper. In that case, I second Mike's suspension response. Depending on the setup it will make your bike want to dive into corners differently. On the other hand, it could make your bike want to stand up as you say its doing.