two questions; one racing one retarded.

[bttrfngrz]

as some of you may know, i started racing last year. i have a 04 xb9r. I need a better suspension setup this year. i was looking at traxxion.com at their cartridge kits, i havn't heard anything ever on super streetbike's mag about them or anywhere else only that danny eslick has them on his 1125r. now i'm not too excited over dropping a grand on tubes i cant find reviews on.
now at my shop my boss said to beef up the fork oil i'm using. i did, but when i was dragging a knee on the bumpy ass course called tanacross sometimes they bottomed out; especialy when i was pressing hard into the turn. now i switched back my fork oil to what the book said for some end of season street riding.
i know racepro might know a little about this. can i get stronger springs some where? and what weight fork oil should i use?

now for the retarded question. at the end of season i had gotten everything powdercoated. during reassembly i could not remember how the transmission breather tube was routed. the service manual i have doesn't really show how it's positioned. so anyone have any pics that can help me?

 

[ridendude]

The oil you use in your forks affects the speed at which your forks react on compression and rebound because of the way it flows through the valving orfices. The spring supports the weight of the vehicle and the gravitational loads as you move around. Using a heavier weight oil would only slow down how fast your forks compress and rebounds. If you're bottoming out, you need to look at a whole lot of things, not just your spring rate.

 

[racepro716]

I've said before that I'm not a suspension tech by any means. Having said that are you sure the forks are bottoming out? On a really bumpy corner I think if they bottomed out you would most likely lose traction with the road and quite possibly crash as the forks are no longer working, they're solid. When your boss said to "beef up" the fork oil what did you do? Just add more oil or go to a heavier grade? A heavier grade will slow the movement up and down, too much oil will lock the forks up and propably blow the seals. Hope this helps, Wayne

 

[GSXdoubleR88ciNINJA]

2nd that transmission breather route ??? I burned mine on the rear header @ the head when I put my engine back in.

 

[bttrfngrz]

tanacross is hardly a race track, it's an old airstrip. there is literally foliage growing out of it. when i replaced fork oil with harley xr1200 competive use fork oil, it performed much better. but it still wouldn't help with the centrifugal force/gravity bottoming out in the corners (i wasn't comfortable pushing it hard in the corners due to the fact of bottoming out. i later found out later my michelinpp2's would actually smoke up slightly in these turns.) so as a more specific question; are there aftermarket springs i can replace the originals with? i appreciate you answering my callout wayne. rep point vote thing for you.

the lesser of the three bottom out corners.

 

[Kole_DeWoody]

There was a set of buell race springs.
Here is the link.
Buell Race Springs

 

[NookieMonster]

I'm not a road racer but have done a bit of suspension setup on my dirt bike I used to race. If I were you I would set the bike up like the manual says for a rider of your weight. After doing that take the bike out and see how it reacts when getting pushed. If you are racing I would think you'd have enough knowledge as to what you need to adjust from the feedback the bike is giving you.

Also, I have an 03 XBS and this past year I have noticed that the front end feels weak. It seems like it is alot softer than when I got the bike back in 05. I ended up having to crank up the springs in the front to keep it up to par to my riding style. I am hoping the rebuild I just did on the forks will fix this but I am afraid the springs have just lost their tension and I may need some new ones.

 

[buelladdicted]

I dont know your location,but in So. Cal. the guy to know what will get you the best results for your racing suspension is the manager/racer of the glendale HD ,buell racing team.He could tell you who to call. I believe he got best results having his stuff revalved and springed w/ ohlins,componants.I dont know what his capacity is w/ the buell plant closeing, but his name is Earnie Snair.Wish I could be more help,but I havent been on a track since 1'' preload spacers, heavy oil were almost as good as it gets.

 

[racepro716]

Was thinking about this at work today. I would add more preload to your existing stock setup to start. These bikes were designed to work under high loads. Having said that, your bike is 6 of 7 years old and the stock springs may be sacked out. Check out the other posts on here for after market springs. At $75 they seem like a steal. Wayne

 

[fahren]

How much do you weigh? I wouldn't go from 5w (standard) oil up to 10 unless you are over 175 or so. But if you are over that weight range, then moving up to 10w would make a difference for you.

 

[bttrfngrz]

alright my preload was maxxed out and my compression/ dampening was at it's perfect setting. the manual doesn't really apply in this situation. i'm gonna see if i can find some aftermarket springs that fit the original diameter fork tubes. hey wayne did you have a rule of thumb about warm tire pressure vs. cold tire pressure? i was told a perfect tire pressure has a four psi differance between hot and cold tires.

 

[NookieMonster]

Just check out EBR, I do believe he has springs to drop into the XB forks.

 

[racepro716]

Jeeeze, my last race was like...15 years ago or so. Let me scrape off a bit of brain rust...I seem to remember 10% between hot and cold was ideal. I think we ran 33-35 psi front-back cold. That was on a 125GP Honda. I'm pretty sure we ran very close to those numbers on our B.O.T.T EX-500. I believe four psi is a false number, it's a percentage you're looking for. Just wondering, did you take a race school? This should have all been covered. If you don't know, tire psi has to be taken the instant you get off the track. As always, hope this helps, Wayne

 

[bttrfngrz]

no race school. just dirtbike racing classes. and for anyone wondering about the breather tube it gets ran around the starter motor up into where the wires are going, ang goes into the the opening above the top of the rear shock mount. and gets looped and zip tied to the suspension.

 

[cap44]

yes 10% is a rule of thumb but it also depends on what tires you are running. Dunlops I run with more air than Pirelli's. The first thing you need to do is set up your sag. About 35 mm from unloaded to you with all your stuff on sitting on the bike. That will give you a baseline to work from. Do that first if you can't get the sag, that will tell you whether you need heavier of lighter springs. Once you get the right weight springs, then you set your fork reaction (bounce) with the fork oil weight.