| Author | Message | |||
     Gunner |
Hey Folks, I’m racing an XB12R up at Loudon this year. Looking for some guidance from experienced XB racers on suspension & chassis set up. I did a few site searches but didn’t find anything. My bike is currently set up with an adjustable height Penske rear shock and stock forks (41mm) sprung for my weight. I’m running stock triple clamps and bars. Loudon is a tight, technical track with an emphasis on late trail braking and corner speed. Can anyone provide insight on recommended set-up starting point? Drop forks in triple clamps to slow steering a bit? Maintain stock shock length? If geometry changes are recommended, please advise what and how much? Stick with stock? Thanks in advance – Go Buell Racing! | |||
| Paint_shaker |
PM Xopti. He helped me set mine up. We started with "Higbee settings" and went from there. | |||
| Gunner |
PM Sent. Thanks! Also found a good article in Sport Rider archives. For '03 XB chassis with stock rear ride height they suggest lowering fork tubes to 7mm showing above top of triple clamp. Stock Forks: Preload - 0 lines showing Rebound Damp - .75 turns out Comp Damp - 3 turns out They also give set up for stock rear shock, but I have a Penske. | |||
| Paint_shaker |
The set up may change slightly since you have the adjustable rear shock. | |||
| Rsh |
Read through this article from Roadracing help.com, It's a story about a guy named Mark Gogfrey that raced a Buell, he has posted here before, it has some set up insight. Quote " It has been said that the grass is always greener on the other side of the fence. Many things in life qualify for this cliche. For some time, I have been telling Mark Godfrey, that is a cool looking bike, I would like to ride it some day? For some reason, the Buell has represented a bike that I dont know why, but I would like to race the damn thing. I have known Mark for some time and he has taken a few of my racing classes, but over the last few years, I also learned to appreciate Marks approach to racing. Fast-forward to December 2003 and I find Mark has submitted an application for the sponsored riders for my new company (Racing Performance Services) and I dont hesitate to sponsor him. December rolls around and Mark and I are talking about how to make his Buell faster. Mark had remarked very positively about some fork work that I did last year. Although I had felt his suspension during setup, I had actually used settings that are not recognized by most tuning charts as the normal? setup. This variance would very effectively guide me in my approach to development on the Buell. Mark made his mind up and said, Just do the works!!! That makes the decision making easy for the tuner. Many times, the Expensive way? actually makes it the cheapest way. Most riders will spend $300.00-$500.00 chunks three or four times, before they realize, Let me just do this right. I told Mark that the best route was to install a Penske Shock and a Traxxion Dynamics valve kit on the stock Showa forks with Traxxion Dynamics racing fork springs. For the forks, I only installed the FVK-1S10 Compression kit and upgraded the shim stack on the rebound piston. Showa actually makes a decent piston in most OEM forks. The only exception is Honda, which uses the HMAS piston(s) in their OEM forks. Those pistons are junk for the most part. We were in good shape with our selection. One other item of advantage is that my company (Racing Performance Services) is one of Traxxion Dynamics top authorized dealers. With Traxxion Dynamics owner Max McAlister experienced with Buell XB development, this would provide some added support (We thought). First up was the installation of the Penske Shock. We chose Penske, because quite honestly there is not a better shock. The first thing you notice is the unmistakable quality of the Penske Damper especially when compared to the stock unit. The model we chose was the 8981, which is the basic twin clicker. We had a Hyperco racing spring (Hypercoils) matched to Marks weight installed and with the adjustable ride height felt we had everything we needed to make the rear end hook up. Installation of the Shock was a bit of a challenge. The first obstacle after putting the bike on jack stands was preparing the Buell for fitment. After removal of the stock shock, you immediately notice the cooling fan behind the rear cylinder. As I looked at the Penske shock I immediately thought, Man, I hope I dont have to take that thing out.? Well, you have to remove it. It appears easy at first as it is held in place with just a couple bolts, BUT loosening it up and getting it out turn out to be two different things. The only way to remove the fan unit intact was to tilt the motor forward or risk breaking the entire assembly by bending the fan to squeeze through the tight space. I opted to get a Dremmel and slice one of the ear/tabs off and this allowed a clean repairable alteration to the cooling fan as well as a quick and easy way to cut it out. Once out, it goes fairly smoothly from there. The biggest issue to overcome is to decide where to place the remote reservoir. The Penske as ordered comes with a 14? hose for the reservoir. Future installations will have an 18? hose so that you can mount the reservoir in the stock bracket. OK, the shock was installed and ready for action, now it was time for the forks. The Showa forks on the XB9r are the same basic forks on the Aprilia RS-250. I mention this as I cringe when I think of this not because the forks dont work, etc. it is just that you have to really stay on top of your work on these forks. Most Showa cartridges are made of aluminum, but these have steel cartridges. The main problem I see with these is the steel seems to promote sludge more than Aluminum and quite honestly, I dont believe the cartridge has the accuracy/integrity in machining that the aluminum cartridges do. In the end, I make very sure that the piston/check plate have NO leakage as I believe the cartridge does not promote mechanically acceptable sealing around the compression piston. If indeed there is improper bypass of the low-speed circuit around the piston/cartridge, I dont want it to be because the hi-speed stack/piston is not correctly assembled. The other problem with these forks is that they have a peculiar design that generally destroys the outer bushing every time you disassemble the forks. I keep them on hand, but that is another 30.00 expense. The last thing that has to be done is the fabrication of custom spacers. This is an important item as the OEM spring is a unique length that is specific to the Buell. I wasnt even concerned as I figured I would call Max McAlister like I do every couple of weeks and ask him how long to cut the spacer and he would bail me out like he normally does. Well, not this time. Max did not keep any of his notes from the Buell work handy and said he would have to see it before he could tell me the correct info. Well, I told Max I would send the correct info when I completed the forks so HE would have it written down. No worries, it only added about 10 minutes for me to dissect the forks and get the correct spacer length. All told, the Traxxion Kit gets installed which includes a 1.0kg set of springs, FVK-1S10 Axxion Valve Kit for compression, upgrade of the rebound stack, complete a full service, and check the forks for proper serviceability. The last step includes making sure the rebound/compression low-speed adjustment has a full range of adjustability. The suspension work is complete. Mark and I plan on making the Next Oak Hill track day to do some final setting up which luckily is within a week. During the week, Mark and I talk on the phone a few times and start getting excited at the thought of what this Buell will do. I look through the CMRA (our local road racing sanctioning body) and see that if we can run a 1:29 on the bike then we would be on par with most of the top running Expert D-Super bike frontrunners. I already have plans of running 1:29s and am already thinking about how the bike could win a D-Super bike event. (Maybe we never stop being novices) Mark and I arrive at the track and because of the announced Oak Hill workday, it is packed. This is bad as it means my trackside business is going to be slammed with business and I would not get time to ride. I worked my ass off until 1:00 and finally got some time to ride the Buell. Mark had rode the bike that morning and raved about it. I was glad as this indicated we were definitely achieving our goals. As I entered the track, I realized that it has been 4 years since I have ridden a twin in anger on the track. Complicating this is the unusually low redline on the Buell. After hitting the rev limiter 4 or 5 times in three turns, I settle in and shift at 6,000 RPM. The other thing I noticed is that it felt like a real race bike (i.e. GSXR/R-6/Etc.). Impressive. The front and rear hook up with the same characteristics as a top handling super sport bike. I take the rest of the first lap and introduce/acclimate myself to this Buell. As I start the first full lap, I notice that the bike is very stable through turn one until I go to counter-steer and almost crash when my hands keep hitting the fairly when I tug on the bars. This happens repeatedly for the entire session. I pull in after 3 laps and tell Mark about his and he immediately cuts the tabs off the fairing and kisses the $50.00 or more goodbye that he would have got from selling the thing. I also noticed the bike did not turn well. I recommend to Mark we raise the rear ride height some more. I go back out and can immediately tell a difference. I turn a best lap of 1:35.5 and realize when I come in from the track, we are not even close to where I want us to be. My main complaint was the front just didnt flick? into a turn. I did not believe it was Geometry related as much as a fork issue that was not letting the front end dive? into a turn. I asked Mark to bring the forks to me the following week so we could go back out to Oak Hill the next weekend. He agreed and we had a debriefing of the Buell performance. Overall the Buell was rock-solid stable. Although it did not dive into the turns like I wanted, it still was a very rideable/tractable bike that a rider could quickly learn to ride fast. I was very happy and at the same time disappointed that we were still far off from where we should be. I told Mark that I thought the problem was related to the forks and that I wanted to drop the fork oil level to induce dive on the front. He said, OK, do it.? Mark ran the forks over to my shop that week and we spent an hour or so bench racing. I took the time to take an extra 10mm off the custom spacers I made to put the pre-load adjuster on the forks in the middle? of the adjustment range. I additionally dropped the fork oil level by 20mm. I could immediately feel the difference just pushing on the fork. We head back to Oak Hill and I adjust the compression and rebound as well as reset the spring sag. Mark came in and immediately raved about how the bike just dove into the turns. He in fact said that it took him a few laps to get used to how the bike just dove in. He also added that the bike did not feel as stable as it did before. I went ahead and rode it for a lap and figured out very quickly that with the increased dive, the bike did not have enough trail to maintain stability when the fork was compressed in a turn. I quickly came in and told Mark that we need to raise the front end 2mm. (I had noted that the Buell had yet to dive very much on the front end ever since I started working on the bike. I also noticed the forks are really raked in? with stock ride height. I had mentioned several times to Mark that we had to be careful to not drop the front end because of this. All of this information is what enabled me to realize that the extra dive was decreasing the trail and causing the instability.) Mark went back out and raved about the performance. He had run his best lap ever (a 1:36) and felt that we got it right! I have to say at this point, I somewhat dropped the ball. I was to ride the Buell one last time, but before I did I rode 3 different bikes with different shift patterns immediately leading up to the riding the Buell. As I got on the Buell, something that had never happened to me before happened. After riding about the other bikes for over a half hour immediately before my Buell ride, I did not know what bike I was on and what shift pattern to use. The over half hour of having to remind myself which shift pattern I was on (GP/Street Shift) wore me out mentally. I literally stopped on the track in Turn 4 and talked to myself in my helmet and also told myself, To get my shit together.? After 2 more laps, I finally got back in the groove. On the 4th lap I turned a 1:32.5 and was ready to really start pushing the bike. Unfortunately, the bike started dying immediately following Turn One. The Buell was running out of fuel. CRAP!!! I pulled in and Mark and I agreed we got the bike to where we wanted and that it was time to call it a day. I really wanted to turn a 1:29 on the thing, but I was also being hired on that day to work with a few riders and unfortunately that is how I make my living. So, Mark loaded up the bike and we felt really satisfied that we accomplished our goal of getting the Buell to handle the best it can. With all that said, the Buell in this configuration is one hell of a great handling bike. Some more thoughts. Mark said that the Buell was screaming when I rode. I usually keep the bike in the power range and accelerate hard and Mark had mentioned that bike sounded/looked/was fast when I was on the track. At the same time, I had noticed Mark was notably faster looking when he was on the track. I dont mean a little bit, BUT a lot. His lap times definitely proved the point. For me, that let me know that the mission was accomplished. I have to say that Mark rode faster and more aggressively than I have ever seen him ride which tells me the bike is comfortably fast and stable. I want to thank Mark for allowing me to be part of his fun. Mark and his family are great folks to know and I believe the cornerstone of his fun. Without our families being part of this (or at least accepting), we cannot focus on the track and the tasks at hand. I believe Mark will do VERY WELL this year and I am excited to be part of that fun. About the kit? All told, the kit? we put together costs approximately $1450.00. The shock cost is $899.00. The full service/upgrade on the forks is $550.00. There are only two or three folks in the country that I would trust to do the work on the forks and I would encourage any individual that is contemplating doing this work to check the credentials of their suspension professional on this product. Obviously, RPS can handle this work through UPS/Mail. Thank you to everyone to take some time out to read about a really fun project." | |||
| Slaughter |
Seriously - you MUST start by setting your sag at both ends by measuring directly. I assume you have re-sprung both ends to match your "fighting weight?" Regardless, set sag to start at 35mm front, 25mm rear. You can start your compression and rebound damping settings as recommended in Higbee's tables and start working with a notepad and record suspension settings in a log. Your MOST IMPORTANT TOOL for racing is your notebook. Screw engine work - wasted effort until you get suspension/brakes/tires (and pressures) sorted. No need to work on engine unless you have some holes in your powerband. Confidence in Steering/turning/braking will drop more off your laptimes than more power EVER will if you are "uncertain" on the bike. You didn't say if you have high and low speed damping on the Penske... but basically, you ought to start with the rear ride height pretty much stock. If you haven't yet gotten spring rates on both ends to match your weight, get on the phone NOW with your visa card in hand to Traxxion Dynamics. If you did buy from Traxxion, get THEM to recommend starting settings. They've worked with XB racers since day one. Can't say enough good about them. | |||
| Blake |
Mark Godfrey and Marcus McBain, author of the above and excellent suspension tuner, are both wonderful people. They were both frequent contributors to BadWeB during their exploits. Hope they are both well. http://www.badweatherbikers.com/buell/messages/327 77/48536.html?1080110632 | |||
| Blake |
A quick listing of posts by Marcus here on BadWeB...
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| Paint_shaker |
The following are my suspension settings from my 2009 Championship Season; Front; Preload 4. Compression 1.25. Rebound 1.5. C&R are turns out from max. Front Comp was 1.5 prior to this. Rear; Preload 4. Compression 1.25. Rebound 1.5. C&R are turns out from max. Front sus has hyperpro race springs w/ 10/20 fork oil. Rear shock is stock w/ race spring. Tires were either Pirelli Dragon Super Corsa DOT, or B-stone 003 DOT. 180 rear. |
Marcus McBain on BadWeB Buell Forum