XBR/S - The Fastest Steering Bike?

[Rogue]

Everytime I read about road tests of the XBR/S by the British bike mags, I always read the statement:  "fastest steering bike".

What does that really mean?

If you are riding one of those latest and greatest sportbikes like the R1/R6/GSXR's/CBR's you probably understand what that means.  But if you're like me, who's used to and always had big, heavy bikes for quite some time, "fast steering" is a relative term.  Does it mean, the steering is very light and the bike responds to steering inputs very quickly?  I used to think so.  But now I'm not quite sure.

I used to think that my VFR800 steered very quickly.  It had a light steering effort up to a point.  And its relative light weight allowed me to flick the bike into the apex relatively easily.  However, like other bike's I have had, once the speed reaches a certain point, the VFR's steering gets a bit heavy.  

I also used to think my Hayabusa steered quickly.  Although it took more effort to "flick" it into corners compared to my VFR.  PLus, its long wheelbase meant a longer arc on any given lean angle.  I now know better.

Having put over 5k miles on my XB12R, I think I now fully understand the statement:  "fastest steering bike".  Due to its low inertia from mass centralization, and a very short wheelbase, the XBR flicks into corners AND changes direction very, very quickly.  A tight corner feels much less tight on the XBR than say, a VFR.  In addition, it's possible to wait at the very last second, then square off that apex in a blink of an eye on the XBR than any other bike I have ridden in my life.  And this doesn't just happen at speed.  Even when making U-turns, the XBR can almost turn inside a lane with little effort, even though its steering, in terms of its lock-to-lock, sucks compared to other bikes.  Its short wheelbase allows to bike to complete any turn very easy and quickly at walking speed or high speed with any given lean angle.  The reason why it took me a bit longer to realize this is that the XB-R's have relatively heavy steering.  Oh it's light enough.  I'd describe it as moderate.  Almost as if the bike has a steering damper. So the steering feels deceptively "slow".  But it actually is far from that!  Once the bike leans over, it doesn't need to lean far to negotiate any turn.    

Thus, the XBR/S makes the perfect city bike AND on a road with tight, decreasing radius turn after turn.  The bike just plops right over and turns.  Tightening the line is effortless.  

However, all is not peachy.  The XBR/S also have a relatively strong tendency to bump-steer.  Although the bike never feels upset by this, it handles just fine under bumpy situations, it may look unstable to some when they see the bike bump steer.  Althoug it feels perfectly fine when it does it.

What a great corner-carving machine!  

[spinalator]

I recall one magazine calling the VFR a neutral steering bike, which further confuses the issue. Not heavy but not twitchy? The Hayabusa I recall as being described as being planted. I know Rob (veefer) and others have shimmed the rear and dropped the front to quicken up the turn in, but can you or would you do the opposite to the XB?

[littlefield]

'Bump steer' is exactly the term I've used to describe my Ulysses behavior when encountering a bump in a corner. I reduced the preload in the rear a little but haven't had a chance to check it out properly.  If that doesn't help I'll try the rebound damping. With a proper setup I'm hoping to solve the problem.

[CBRXXBLACKBIRD]

Don't they all steer quick due to the short wheel base?

[littlefield]

Yup, short wheel base plus relatively little trail.

[Rogue]

The bump steer doesn't bother me one bit.  I notice it, that's all.  It's also ONLY apparent at low speed cornering and when the bumps are big.  Little ripples or sharp bumps don't upset it.  However, the quickest way to minimize its effects is to relax the grip to the bars.  The bike self-corrects.  

As far as shimming the rear/lowering the front to quicken up the steering on the Firebolt, Sport-Rider magazine did just that on their Firebolt with the aim of "quickening up the steering".  It turned out that this doesn't work for the bike as it became way too twitchy.  Sport Rider was trying to make a Firebolt handle like an R6.  When it fact, it goes against the basic design of the bike.  

The reason the steering "feels" slow is to offset the steep steering angle.  If the steering of the Firebolt was made to be as light as say, a CBR600, the Firebolt's short wheelbase would make it very, very twitchy and ultra sensitive to bar pressure.  So, Buell built in some heaviness to the steering to offset this.  It is just the initial pressure to change direction that seems slow.  But it really isn't.  

Trust me.  The Firebolt does NOT need any shimming or any other adjustment to quicken up its steering.  That's because it doesn't take much lean angle to get the bike the turn.  Put enough pressure on the bars and the bike will flick right into a turn faster than most other bikes I have ridden.  Then, the short wheelbase allows it to cover a very small arc.  It is very, very manueverable.  

[Kootenanny]

What I like about my Firebolt is how easily it can change a line even while heeled over.  Yes, the steering is a bit "heavy" compared to some Big Four sportbikes I've ridden, but after a short adjustment period I found the light steering on some other sportbikes almost annoying; the 'Bolt feels very solid and planted, yet it reponds instantly to any input.  Feels like I'm riding a motorcycle, too, not piloting a video game console...

I read an interesting article by a journo who rode Rossi's 06 MotoGP racebike--he was surprised that the bike had relatively heavy steering and "soft" brakes, which required a fair bit of lever strength.  Apparently this is the setup Rossi prefers--he's all about making the bike as easy to ride as possible, so he can concentrate on going fast rather than on controlling the bike.

[Mookie]

'Bump steer' is exactly the term I've used to describe my Ulysses behavior when encountering a bump in a corner. I reduced the preload in the rear a little but haven't had a chance to check it out properly.  If that doesn't help I'll try the rebound damping. With a proper setup I'm hoping to solve the problem.

I'm pretty sure the Ulysses steering head angle is much less severe than the firebolt/xb chassis.  The XB is an almost vertical 21.5 degrees whereas the Uly is more like 25 degrees.  Sounds to me like you've definitely got some adjustments in your future.