[MorphiasX]

I lowered my 04 GSXR 600 4" with lowering links in the back, and 2" in the front by bringing the forks up in the triple clamps. I have to have it this low because im short (5'3"), and even with it lowered this much im not close to being flat-foot. Anyways, now that it is lowered, when I shift and downshift (more when I downshift) the bike chatters (seems to be coming from the front). I have not adjusted the compression and rebound at all, so I figure that is why. Either that, or the shock is bottoming out when the front dives down. What do you guys think? How would I adjust the compression and rebound? I know its done with the dials on the top and bottom of the forks, but what do they need to be adjusted to? I do have alot of mechanical experience doing truck motor conversions, suspension, and fabrication and I lowered the bike myself. So I am mechanically inclined, I would much rather do it myself rather than fork over cash to a shop.

Thanks in advance

 

[its_nero2]

can you be a little more specific about the riding scenario....meaning downshifting from hard revs? while coming into a braking zone? i say this because downshifting from high revs can cause chatter if not done properly. i went through this for a while when i first started going to the track. when you don't match the engine speed right you'll get engine chatter. some think it's chatter from the front.

 

[MorphiasX]

The scenario ranges... When I first get on the bike to go to work in the morning it seems to chatter everytime I shift (up or down) while the bike is still rather cold (around 100 degrees) but seems to stop the chatter for upshifting for the most part after it has warmed up. But then when im slowing down to stop or make a turn if I click down and let the clutch out (slowly to allow for the engine to slow the bike down) the bike chatters like crazy. I know how to work the clutch with shifting both up and down, I have been driving stick for 3 years. I have buddies that ride as well, and I see them downshift in the same scenario and they dont get the chatter that I do, both of them have stock ride-height bikes though (03 gixxer 750 and 02 CBR 600). The chattering in this scenario always occurs. I really think it has to do with me lowering the bike, and not adjusting the rebound and compression.

 

[kevin_stevens]

Compression and rebound damping don't innately have anything to do with the ride height of the bike, though with such dramatic changes you've made it's hard to be sure of anything - but it's not the first place to look. Any kind of "chattering" on *upshifting* seems very odd. How much do you weigh? What do the other guys experience if they ride your bike?

KeS

 

[MorphiasX]

I weigh about 130 lbs. My friend with the 03 gixxer 750 is the one who rode the bike home for me when I bought it, and it did not chatter at all then. That was before it was lowered. After it was lowered a few people have riden it and noticed the chatter on downshifting as well. The others that have riden it range from 150 - 200 lbs.

 

[Land-Shark]

I am going a limb here and going to say your not sure what chatter is. In basic terms you either have wheel hop which is suspension related or brake chatter. Chatter can cause the wheel to hop but it would be felt long before that happened. Since this is a used bike I would bleed the entire brake system anyway and inspect the pads, calipers and rotors for binding and warpage.
Now more to the upshift down shift problem without braking. If you have severely changed the geometry as you have then you caused the front to ride to high. This will give you bouncing like the rebound is to low. In short you made a chopper out of your sport bike. You cant lower one without and equal match to the other. So you now need to lower the front to 4" also. I urge caution though because now you have clearance issues with the radiator and fender, not to mention the ground. You also have changed the geometry so much that the angle of the swingarm is now causing the chain to climb further exagerating the squat.

More info would help.

 

[MorphiasX]

I really do not think it is brake related, because it does not chatter with braking at all. It only chatters if I downshift (and let the clutch out at each click down to let the engine help slow me down, not just pull the clutch in and click down to first). Yes I know I only brought the front down 2", I did so because I didnt know how to go any more. When I brought the forks up in the triple clamps, the forks have little steps on them that seem to act as a reference point. Well, it seems that it wont let you bring them up anymore in the triple clamps more than 2". Besides, the forks would be sticking even more out of the top of the top of the triple clamp top.

I will take video of me riding and downshifting with the chatter taking place tomarrow, and upload it to show exactly what is happening.

 

[Land-Shark]

I just wanted to stress checking the brakes on a 4yr old bike. As for lower the bike I assume you just added longer link rods (dog bones). What really needs to happen is the shock and fork need to shortened to keep the bike as close to the preformance at stock height. http://www.racetech.com/emaillist/news/RTnews-061025.htm
I would really like to see the vid since this is most a best guess as to whats really happening.

 

[MorphiasX]

Alright, I had a buddy take a video of me coming down the street. I was in second gear, and downshifted to first. The chattering is VERY apparent in this video.

http://members.lycos.co.uk/morphiasx/bike/MVI_0447.AVI

 

[sportbike solutions]

Woooooooaaahhhh there!

Did you say you dropped the bike 2 inches over the forks? If so, that's your problem. The fender's probably hitting the lower triple anytime the suspension compresses the least bit.

Also - I don't have a pair of 2004 forks in front of me - but I'm pretty sure your forks have flats on them where the lower triple is designed to clamp down. At 2", you'd be on a smaller diameter portion of the fork, and therefore not clamping properly.

Best thing to do would not be to lower your bike at all. But if you have to lower it, there are other ways. What you've done won't work. And it's dangerous.

 

[IridiumRed]

YOU DROPPED IT 4" IN BACK AND 2" UP FRONT ...and you wonder why you have problems??

You dont need it that low, you really dont

I'm 5'4, and my bike (2004 1000) is lowered about 10mm up front (to steepen fork angle) and is probably 1/2" TALLER at the back (extra cornering clearance, faster steering, and it seems to like that setup - I've got an Ohlins shock back there)

I've got zero problems riding it on the street. You just have to plan ahead. I'm cool with everything but if I have to move the bike much I just get off of it. Its so much easier to roll a bike around when you're standing next to it...

I say go back to stock height, or if you must, lower it like 1 inch from stock front and rear, maybe 2" in back if you have to...

That will probably solve a lot of problems ride it like that for a while.... and then you might find you have no problem and then you can go to stock height

Its a confidence thing. If you are medium height (lets say 5'8 to 6') there are probably lots of bikes you can flat foot. Well, if you get used to that, then the first time you can't get your feet flat you feel uncomfortable

ME? I'm so short, I can't flat foot anything, so I just got used to it and dealt with it!