2011 Literbike Streetfighter Shootout

[donw]

I think you guys will have to eat brown bag lunches for more time than you think. I bought my new 2010 Z1000 for $8,000, plus sales tax. EBay had a couple of them for that price, so I took the postings down to my local Kawi dealer who matched the price. I could not even come close to that price for a Speed Triple. Great article, but in the real world, retail price is less meaningful than true market price.

[Morbo the Destroyer]

Originally Posted by YellowDuck

Adding preload does NOT make the suspension more "taught" or less "plush". It just extends the shock and raises the rear ride height. The amount of force it will take to compress the spring a certain amount will not be affected by preload (unless the suspension is topped out). 90% of riders don't understand this, and part of the reason for that is because people who write for motorcycle magazines and websites keep screwing it up. I recognize that it is extremely non-intuitive, but so are lots of technical matters. Let's try to get past this misconception, shall we?

Now wait just a minute there, Ducky. I've had two bikes with adjustable preload on the rear spring, including the current DL1000 that has a hydraulic preload.

Yes, cranking the knob to the right does increaste the height of the rear end, turning it left lowers it back down. BUT, given an equal load when compared to having it lower, the rear end is noticably stiffer and reacts more to bumps.


I'm just a layman when it comes to suspension, but there is no doubt in my mind that the ride is "softer" with the compression down than it is when it's up.

[YellowDuck]

Hi Morbo -

I can't 100% explain what you are feeling on your bike, but it is possible that the increased harshness of the rear over bumps when you increase preload is caused by the increased rear ride height, which takes some weight off the rear suspension and shifts it to the front. That will indeed cause the bike to "work" the rear suspension less, so that there is less swingarm movement (and more seat movement!).

Again, unless the suspension is topped out (which it had better not be with you on the bike!), adding preload does not compress the spring - it just changes where the shock is in it's travel, with the same spring compression (again, barring big changes in F/R weight distribution).

The purpose of rear preload is i) to set the compromise between positive and negative shock travel (i.e., to prevent the shock either topping out or bottoming out), and ii) to set the rear ride height. On some bikes (ii) can be set independently of preload (ride height adjuster).

Also, note that most bikes have a rising rate rear linkage - the suspension gets "stiffer" (moves less per unit force applied) as it is compressed. This means that as you add preload and raise the rear ride height (extend the rear suspension), it actually gets less stiff, not more.

[YellowDuck]

Originally Posted by Morbo the Destroyer

I'm just a layman when it comes to suspension, but there is no doubt in my mind that the ride is "softer" with the compression down than it is when it's up.

There is a terminology problem here too. By "compression" I think you mean "spring compression". You are indeed increasing that with preload in the sense that with the shock fully extended (e.g., if you take it off the bike), the spring will be more compressed. However, once you sit on the bike the *total* spring compression (preload + however much more it moves under your weight) will be the same regardless of the preload setting.

If by "compression" you meant "compression damping" (not likely adjustable on a DL1000 ?), then yes, cranking that up will definitely make the suspension more harsh!

[Morbo the Destroyer]

Ducky,

This is interesting. Come to think of it, as I turn the knob, the whole top of the spring/shock unit rises up. I guess that really can't put any more weight or compression on the spring, can it? Unless of course I hit somethat that stopped the bike from rising, which would then "push" down more on the spring. But that doesn't happen, the subframe just goes up.

So now you've got me wondering why the bike feels stiffer and bouncier in the back with the shock higher. I know before I put the HyperPro progressive spring on, I always rode with the preload mostly all the way up; it just felt better. But the suspension guy who put in the new spring said to leave it all the way down to get the right "sag," which I do except when carrying a passenger. And the cornering is much better.

I think you're right, it doesn't make sense that raising the back of the bike makes the ride softer or harder. But it sure seems like it does!

[YellowDuck]

Originally Posted by Morbo the Destroyer

Ducky,

This is interesting. Come to think of it, as I turn the knob, the whole top of the spring/shock unit rises up. I guess that really can't put any more weight or compression on the spring, can it? Unless of course I hit somethat that stopped the bike from rising, which would then "push" down more on the spring. But that doesn't happen, the subframe just goes up.

So now you've got me wondering why the bike feels stiffer and bouncier in the back with the shock higher. I know before I put the HyperPro progressive spring on, I always rode with the preload mostly all the way up; it just felt better. But the suspension guy who put in the new spring said to leave it all the way down to get the right "sag," which I do except when carrying a passenger. And the cornering is much better.

I think you're right, it doesn't make sense that raising the back of the bike makes the ride softer or harder. But it sure seems like it does!

Bingo. Awesome. You may be the first person I have successfully converted. You just made my day.

Other than what I mentioned above, another possiblity for the feeling of harshness is that at high preload settings, you are actually topping out the suspension over some bumps. That will definitely do it, because at a certain point on rebound the shock is fully extended and then the bike is suddenly trying to pick the whole weight of the rear wheel assembly right off the ground! So, you go over a bump and the spring compresses, then as the shock tries to extend again it reaches the limit of its travel, the weight of the wheel suddenly slows the rear from rising, but of course your butt keeps going up, comes off the seat then lands on it again. Harshness. But not due to spring compression!

[neo1piv014]

I was just wondering if you guys have considered doing "as tested" prices next to the MSRP's for each bike. I know when you look at bikes like BMWs and Triumphs - both of which are almost never sold stock - the value proposition changes a bit. Looking at that S3, you've doubled the price gap between it and the Z just by adding those pipes. I know you guys have to work with what you've got (and you do an awesome job), but I would have really loved to see this shootout done with bone stock bikes from every manufacturer involved. I'd be willing to bet that without those better flowing pipes out back, the S3 and Z dyno readings would have been noticably more similar.

[Kevin_Duke]

Originally Posted by neo1piv014

I was just wondering if you guys have considered doing "as tested" prices next to the MSRP's for each bike. I know when you look at bikes like BMWs and Triumphs - both of which are almost never sold stock - the value proposition changes a bit. Looking at that S3, you've doubled the price gap between it and the Z just by adding those pipes. I know you guys have to work with what you've got (and you do an awesome job), but I would have really loved to see this shootout done with bone stock bikes from every manufacturer involved. I'd be willing to bet that without those better flowing pipes out back, the S3 and Z dyno readings would have been noticably more similar.

Yeah, we always try to keep test bikes in their stock configurations, but that didn't work out in this case. The S3's dyno numbers certainly benefited from those pipes.

[mariovtr]

As a KTM Superduke owner, I wonder how my ride would rank against these. I have tried a 2010 Speed Triple and was unimpressed. Have they improved much since?

Anybody care to comment?

[trenttheuncatchable]

Have you tried a Tuono? Did that impress you at all? This kind of comment reminds me of someone who likes one superbike and is "not impressed" by another.