| Author | Message | ||
     Duggram |
After an expert rode my 1125R he suggested, among other things, raising my fork tubes 2 mm. Just now I was talking with a guy at Airtech and he told me that he raised the fork tubes on his friend's early Buell 6 mm. What do others think of this? | ||
| Xl1200r |
Raising the fork tubes will make the rake even steeper than it already is (and Buell's have a steep rake to begin with). Why not just increase your rear preload by a click? | ||
| Jmr1283 |
dido on te rear preload. it gets to a point with me that the bike turns too easy for my liking. theres really no need to adjust the fork tubes. but im not racing like u are. | ||
| 1_mike |
Raising the rear preload...stiffens the rear...not always a good thing! The rear preload should not be used to set anything in the FRONT of the bike. Dug - it's not rocket science..try a given small amount, give a try, push it drive slow, make sure you go at it slowly to make sure you haven't over done something. If your happy with that change, go a little farther and give it another go-round. My guess is you probably won't feel much at .08" or .120". May have to go a little further...but, .120" is probably a good place to start. Mike | ||
| Xl1200r |
Raising the rear preload...stiffens the rear...not always a good thing! Adjusting the preload doesn't stiffen anything. All you're doing is preloading the srping, which means the more preload you add, the less sag you'll get once you add teh riders weight to it. Assuming you haven't added so much preload that the spring doesn't flex at all once you sit on the bike, the spring will always be under the exact same amount of tension once you're sitting on it. The rear preload should not be used to set anything in the FRONT of the bike. Increasing the rear preload is a commonly accepted way of steepening the bike's rake to get it to turn in a little quicker. Lowering the front preload accomplishes the same thing. You use the two in conjuntion with each other so as not to unsettle the static sag setting too much. (Message edited by xl1200r on October 22, 2008) | ||
| Jmr1283 |
They tell u rate in the manual to use the preload to adjust the bikes rake for improved handling... i guess they where wrong. lol now saying that its not like the manuals the creditable. lol | ||
| Carbonbigfoot |
The preload WILL make the ride stiffer. The springs get progressively more resistant the more that they are compressed. The more preload, higher the rate of change of spring compression per distance. Really whiz-bang shocks will have independent ride height adjustments. That would be ideal for changing the bikes attitude. Not to say that the preload thing won't work, in fact, it is in the manual, and does work. It's also easy. Most people don't want to screw with the forks, and you can accomplish virtually the same thing with the rear preload. For most of us, we will never get to the point that we can ride the bike to the level of this minutia being relevant. But that never stopped me from having an opinion! R | ||
| Xl1200r |
The preload WILL make the ride stiffer. Incorrect. This is the simplest way I can explain this. Take a 12" spring and place 100 lbs of weight on it. Let's say it compressed 6", and is now 6" long with the top of the spring sitting 6" off the ground. Now raise the bottom of the spring while keeping the top stationary by 3". This is the equivalent to 50 lbs of weight. Now put the same 100 lbs on the top of the spring. The first 50 lbs won't compress the spring any because it's only counteracting the preload that was added at the bottom. But the next 50 lbs will compress the spring another 3 inches. So now the spring is compressed to a height of 6" (same as it was with no preload), but the top it sitting 9" off the ground. The bottom line is, as far as ride stiffness is concerned, changing the preload will not affect the stiffness of the spring once loaded (assuming the preload isn't more than the weight being put on the spring...rider + bike). The downside is you will decrease the static sag, which essentially leaves less travel for rebound. | ||
| Slypiranna |
I disagree. The more you preload a spring, the firmer its new state becomes. This is ONE reason why valves springs have different installed heights...spring pressure/more force on the seat. More preload = more force @ rest & a firmer ride/rate within the remaining travel. There would not be a reason for independent ride height (along with preload) adjustments on some bikes if this wasn't the case...IMO...mm (Message edited by slypiranna on October 22, 2008) (Message edited by slypiranna on October 22, 2008) | ||
| Xl1200r |
The more you preload a spring, the firmer its new state becomes. The firmer its *relaxed* state becomes. All you are doing is limiting how much the spring is allowed to expand, you are not changing how much force is needed to compress it. More preload = more force @ rest & a firmer ride/rate within the remaining travel. You can't change the laws of physics which govern the steel in the spring by turning a screw. There would not be a reason for independent ride height (along with preload) adjustments on some bikes if this wasn't the case...IMO...mm The reason is that when you adjust preload, you are also ajusting sag. Too much or too little sag is not good. However, having the preload and ride hight seperate allows you to adjust the sag and ride height independantly. I know it all sounds counter intuitive, but you are not stiffening the spring any when you jack the preload up. Maybe it's easier to think about with a rider sitting on the bike. If you're on the bike and adjust the preload up one click, the bottom of the spring raises up. The seat (with you on it) will raise by the same amount. | ||
| Slypiranna |
http://books.google.com/books?id=84hF-qoR5I8C&pg=P T166&lpg=PT166&dq=spring+preload,+harder+ride%3F&s ource=web&ots=FYx2wGQ7Sj&sig=B2r4eyLrFlZDzLW5I2nzw 5Mw6cI&hl=en&sa=X&oi=book_result&resnum=7&ct=resul t#PPT329,M1 Grap a beer or three...but good info non the less. Preload is discussed in two separate sections... Xl1200r, If we were talking a linear rate spring, I could understand the laws at which you and many others have pointed to. But progressive rate springs will increase their rate the further they are compressed which is why my head thinks this way...mm (Message edited by slypiranna on October 22, 2008) | ||
| Xl1200r |
Slyp - straight or progressive rate springs make no difference. You are still always adding the same amount of weight to the spring, the pre-load just gives a head start. |
