TWF Racing - Forums. Posts Latest Activity. Page of 1. Filtered by:. Previous template Next. Effect of fork swap on steering geometry - what all goes on? February 24th, , PM. So - a 'new and improved' GSXR front end is being considered for the SV Other than the obvious improvements with adjustable damping suspension, bigger springs and better braking, what else happens that maybe isn't fully understood? Hopefully what follows will give some insight into the mathematical geometry of what changes beyond those cited above - track experts like Zoran can give you much better information on how these changes actually translate into 'real world' feel, in terms of realized effect on handling.
But please recognize - there are changes, especially dependent on which components you select! This site has a much more racing 'bent' so I expect the subtleties go far beyond whether the gold or the black calipers 'look' more bling! The brakes are also significantly better!
But I see posts on 'other' forums where suddenly the newly acquired forks make changes to the way the bike feels and the rider doesn't understand why - I mean, it's supposed to be better, right? As you will hopefully see at the conclusion of that which follows below, changing to GSXR forks is a quite dramatic change to the original geometry. BOTH of these will make for shorter trail independantly and collectively make for very different geometry than that of the original equipment!
Let's understand some terminology first: Rake is simply the angle of the steering head against vertical. The smaller the angle, the 'steeper' the rake.
An angle of zero would be with the forks exactly vertical. Typically the rake would be in the 25 degree range. Trail is the horizontal distance from where a projection of the steering axis intersects the ground to where the front wheel touches the ground.
Universally all motorcyle fork applications will result in positive trail. For negative trail, think of a shopping cart Fork Offset is the perpendicular distance between the center of the steering stem and a line drawn between the center of the forks.
It will want to stay pointed in a straight line if taken to extreme. Less trail, will make the bike much more susceptible to steering input - be that directly from the rider or from external influences!
Taken to extreme, the bike will become unstable with even minor external influences, potentially resulting in the infamously named 'tank-slapper' Clearly we want to avoid either extreme condition - we desire something that is stable, yet responds well to steering input without too much effort. It is interesting to note that over the last 8 years, the big 4 Sportsbikes have been getting progressively longer in their trail numbers!
There is a common misconception that longer offset gives longer trail, but its actually the opposite. Recognize that the length of the forks themselves are not a factor in the math of the equation - however changing the length of the forks will change the rake angle. This can be negated by adjusting the height of the rear end such that the rake angle would remain the same, even if the fork length is different.
Bit recognize of course othe rthings that influences - like ground clearance! Bike looks clean, and damn near stock, save for the front blurpie wheel. I may have the rear painted next winter to match. Top triple turned out awesome! You are commenting using your WordPress.
You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email.
Yep…yet another build…but with a twist…sort of! My buddy calls it the GSVR ! I want to stash my shit in it helmet, gloves, whatever else fits and walk the two blocks to work Complete pictures of build here, will keep adding as I take them.
Share this: Twitter Facebook. Like this: Like Loading Upside-down forks - probably not so important for me, but the main difference is they're a lot stiffer and look really trick 4-pot Radial brake calipers - way more powerful than the stock ones- probably more powerful than I need, but a nice upgrade. And they look really trick Black wheel, black fender - one day, I'll swap to a black rear wheel, buy a black hugger, and the look will be complete.
Thanks to the hard work and investigation of many other SV owners, there weren't that many unknowns involved in this conversion. There was a lot of gray area though, that I will attempt to rectify by publishing what I've learned during my conversion. The complicated parts are with the controls, namely finding a pair of clip-ons that will work with the stock electrical, clutch and throttle cables. I had major problems with mine because they're this weird aftermarket make.
In order to make everything work, a lot of finesse and quick-thinking was required. Anyway, it's all done now. Results My first impressions of the new equipment were: 1. First, the brakes are just incredible. I re-used the master cylinder from the SV the part that you press on to brake as well as my stainless steel line kit, so the only parts that are really new are the calipers the things with brake pads that clamp down on the wheel to stop it.
I think it's the calipers. I barely need to squeeze the brake lever to start slowing down, and if I squeeze with moderate pressure, I start slowing down real fast. Originally I was worried that the stock master cylinder wouldn't handle these new brakes properly, and I'd be squeezing the lever all the way into the bar in order to get proper braking action.
Nothing could be further from the truth. I barely squeeze down and I'm already stopped. In fact, they're so sensitive that I was slowing down before the lever moved enough to trip the brake light switch.
So, essentially I was braking but my brake lights weren't turning on. I had to grind down the brake lever in order to remedy this. The other, major, major thing I noticed right away is that the front end doesn't dive anymore.
The old SV suspension is really weak- every time I decelerated slightly, the front suspension would compress and cause my body to shift forward slightly. When I braked hard, it was really bad, to the point where I felt like I was bottoming out the suspension. In a way, it was good because it taught me to be smooth with the brakes and throttle, not not upset the front end. On the other hand, it was really disconcerting if I had to brake hard before turning, because the suspension would be moving around everywhere.
With the new suspension, I notice the front end barely moves under normal riding. At first it was weird because I was used to the diving action.
But, now that I've adjusted, it's really nice to not have your entire body thrown forward every time you tap on the brakes. I've done quite a bit of riding recently to test my new forks. From looking at dirt pattern on the tubes, I can tell I'm still using a lot of fork travel. The difference is, I don't notice it as much, because it only happens under heavy braking, and the motion is more gradual. This, I believe, is the way things are supposed to be. From here, I'll be learning to tune and adjust my suspension, now that I actually have an adjustable suspension.
So far, I can tell what's wrong, but not always how to adjust for it. Great post Darren, even though I've done this it always helps to see what other folk have done. I've got fiddle with the speedo sensor on mine as it stops reading after 45mph, as I think it's a few mil too far away from the disc magnets. Great thread! With these speedo kits do they need to be calibrated at all? Top post, thanks for sharing Darren. The bike looks really sexy with the gsxr forks and I don't see many sv's in that colour either.
Have you used all the standard sv switch gears for those clip ons? I couldn't fit mine on to early Gsxr clips and still even Tl ones are a tad short. So since it is no longer available, I have uploaded my saved copy for others to use:. Originally Posted by Bobbydigital Thread Tools. All times are GMT.
The time now is PM. Contact Us - SV
0コメント