Quote:
Originally Posted by choneofakind
Yes... but consider where that statement is coming from. It's someone with a medalled racing pedigree in AMA Superbike. Of course it's too soft for him.
|
Based on RT's numbers (once again, for whatever that's worth), it still seems really stiff to me. They suggest 8.364kg/mm for 160lb with their race setting. 9.3kg/mm is over 11% higher than that, good for 209lb. For comparison, their street settings say 8.2kg/mm for 160lb and 9.121kg/mm for 209lb, or making the race specs 1.5-1.8% higher than street. Even if he is a top-notch racer who likes the very firm end of the suspension range, it still doesn't seem right to me that he'd use a spring meant for someone 40% heavier.
With that much difference, I'm inclined to believe there's a problem with RT's data or formula. I know that small suspension measurement differences can result in large changes in the final numbers, but all these little Ninjas have pretty similar suspensions (as indicated by the ease of swapping their parts around), and the NewGen calculator seems to match up pretty well to the race-accepted numbers for the 500. That makes me think their formula isn't insanely wrong. Based on the Ninjas' history of soft springs, it wouldn't surprise me if the NewGen rear is actually softer than the listed 9.3kg/mm.
Maybe real racers really do just use springs that much stiffer. He did say that their fork spring calculations (a while back, before changes of some sort were made to the NewGen calc) were low too. Or maybe he's just a fatty in denial about his actual weight.
Quote:
Originally Posted by choneofakind
This is not a cookie cutter comparison you're making here, Bill. Average Joe like you and me has problems with the front loooooong before the rear, likely would appreciate damping adjustment on the rear rather than spring rate change.
|
Speaking from experience with a binding rear shock mod, I can say that a too-stiff rear will make even a bike with a really good front feel bad (someone with more experience might be able to more easily tell where the problem is, but the bike as a whole felt "bad", worse than with the way-too-soft spring). And if the front is also too soft, the stiff rear will exacerbate the rocking horse effect. If the rear spring really is quite a bit too stiff, getting a softer spring might actually make the front seem less bad because the front isn't being forced to absorb all the force that the rear won't (though you should still install springs of the right rate if you need to).
I've installed a couple springs on one street bike, so obviously I'm an expert now. =) But I tend to agree with the general idea that getting the proper spring rate should be the first step. That'll get it bouncing in the right range, allowing the damping to be most efficient. If the spring is too soft, it'll be moving too much and the damping system will be straining to control the excess movement. But if the spring is too stiff, then it's already not moving enough, so restraining the already-lacking movement isn't going to help any.
Luckily, the GSXR shock can take care of both spring rate and damping settings (assuming you choose one with a spring matching your weight) so you don't have to choose one or the other.
The 600 shocks that most people seem to be using have spring rates in the same range as the PreGen and NewGen OEM springs, so most people probably ended up ok (e.g. the '06-'09 is pretty much the same as the stocker (based on RT's listed data)). It just seemed to me that a lot of people didn't know/care what they needed for their weight or what they were installing - they just heard that a GSXR shock was an upgrade so they bought the cheapest one off eBay. A different year 600 or a 750/1000 might have a spring that better matches the person's weight, rather than just duplicating the stock numbers. Maybe I'm just reading too much into it, but I got the impression that people weren't necessarily informed enough to make the best decision. If you can just make a slightly different model choice when buying your GSXR shock and get one with a spring better suited to your weight, it makes the DIY that much better.