AlphaBird Posted April 10, 2003 Share Posted April 10, 2003 All this talk about forks/shocks has got me curious. Seems that with every improvement--usually resulting in a decrease in sag--frame geometry is going to change. For example--my forks are stock and have 45mm of sag--I have replaced the rear shock and have 25mm of sag---I have shimmed the rear up 6mm, and I love the way the bike handles. Now if I replace the fork springs to 1.0-1.5kgs, I will reduce my front sag by say 15mm---most likely reducing my beloved quick turn in---to get it back I would need to re-shim approximately 15mm to get the geometry back-- Does anyone have any experience with this--I think BDAZZ---jacked his rear over an inch, via a dogbone after he did the forks/Penske??? Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 10, 2003 Share Posted April 10, 2003 Not everything will be equal. You'd have to ride it around and see what you want to do. I found that just raising the fork tubes a little bit gave me the turn-in and feel that I wanted. For whatever reason, improving the suspension gave the illusion of better turn-in, whether it is real or not. Plus of course as soon as the bike heels over just a bit the handling, feel, and confidence are so much better. Well, that's with both springs and valves. Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 11, 2003 Share Posted April 11, 2003 For whatever reason, improving the suspension gave the illusion of better turn-in, whether it is real or not. I'll second this notion. When I re-installed my forks, I measured, re-measured and measured again to ensure I got the 39mm fork height over the triple tree. But when I took the bike on the road the first time with the overhauled forks, I could feel (perceive) a noticably quicker turn-in, so much so I thought I must have inadvertantly raised my forks. When I got home, I took the Heli-Bars off and re-measured a bunch of times. Nope, it was dead-nuts on at 39mm. I have not actually shimmed my new rear Ohlins, and at this point, I don't believe I want to... I am more than happy with the set-up as it is right now. Quote Link to comment Share on other sites More sharing options...
BDAZ XX Posted April 11, 2003 Share Posted April 11, 2003 WC theres a threaded ride height adjuster on the bottom of the Ohlins, by adjusting it, you can adjust your ride height. AB with the adjustable dogbone on I put the bike on its center stand and adjusted it down to where the back wheel is just shy of hitting the ground, check yours on the center stand and you will see how much I dropped the r.wheel. I ran my forks at stock height before. Now that I have gone and broken the dogbone I am planning on dropping the forks 5mm in the triples as well as riasing the rearend via penske shock adjuster just to play with it and see if it helps. Modified suspension only helps keep the wheels on the ground and gives a more comfortable ride. The bike will turn the same regardless of suspension mods if everything is set back to stock positions. You have to raise the tail or drop the forks to induce different handling charactiristics. The geometry has to be changed inorder to change the handling. Not saying a suspension mod wont help while leaned over because the wheels are contacting the pavement in a smoother and better controlled fashion, thus feeling better while turning and much more confidence inspiring. My.02 now where did I put my coffee?? :grin: Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 11, 2003 Share Posted April 11, 2003 Randy, I'd suggest not dropping the front if you can help it. As the front drops, you loose clearance with the fairing. Raising the rear will give you more clearance, but mainly around the exhausts, not the front of the fairing, which is the first thing to scrape. Quote Link to comment Share on other sites More sharing options...
AlphaBird Posted April 11, 2003 Author Share Posted April 11, 2003 FYI---there is NO ride height adj on the Ohlins--apparently they didnt think that we sport-tourers would need it--Yep--I was surprised too :-o Randy I guess I kind of agree---BUT---once you do the forks you cant--change the pre-load, thus the sag---the only thing you can do is adjust the rear ride height---for me--the new springs should raise the bike 15mm in the front from where it is now--the rear is already set at 25mm sag(where I like it)--so to maintain the geometry--either the front goes down(not good for me as i like clearance) or the rear goes up---possibly ALOT like 15mm---- another 7.5mm of shim should do it as the rr height linkage ratio is typically 2:1--just not sure if there is that much room on the shock mount bolt---time will tell Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 11, 2003 Share Posted April 11, 2003 You need to be careful about raising the rear too much. 15mm at the shock is going to translate to about 50mm at the axle. At that point you run serious potential of having the chain jump off the sprocket due to the angles formed between the swingarm and frame. It is advisable never to go over about 30mm raise at the axle. Quote Link to comment Share on other sites More sharing options...
AlphaBird Posted April 11, 2003 Author Share Posted April 11, 2003 You need to be careful about raising the rear too much. 15mm at the shock is going to translate to about 50mm at the axle. At that point you run serious potential of having the chain jump off the sprocket due to the angles formed between the swingarm and frame. It is advisable never to go over about 30mm raise at the axle. Mirth--do you know if the ratio between axle/shock is really 3X--I always heard 2X ?? Reagrdless--the kickstand aint gonna work worth a rats ass Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 11, 2003 Share Posted April 11, 2003 Ratio is dependent on the linkage and swingarm length. On my VFR400 is was about 2.8 or so. The VTR was about 3.4 and the RSVR is around 2.1. If you want to jack the rear up that far, I think you would be better off looking at different link lengths rather than the spacer. The link only needs to change by one or two mm to have huge changes in the rear. I remember on my VFR that I shifted the hole by about 4 mm and the bike looked like it was nose-diving into the ground :???: Fixed that quickly! Then played around with spacers etc to get the roughly right setup. but there was certainly a point where with the spacers that the swing-arm was too close to the bottom limit of travel and the angle was causing the chain to jump off the sprocket under power. In the end I was running about 45mm at the axle over stock, but I was also running a 17in rear rather than the stock 18in, so I had to make up for that. Quote Link to comment Share on other sites More sharing options...
BDAZ XX Posted April 11, 2003 Share Posted April 11, 2003 Randy, I'd suggest not dropping the front if you can help it. As the front drops, you loose clearance with the fairing. Raising the rear will give you more clearance, but mainly around the exhausts, not the front of the fairing, which is the first thing to scrape. I thought knees were supposed to scrape first?? :wink: Just messin with ya. :grin: I am aware of the factors involved and will experiment with it till I like the set up again. I am really a newbie in suspension "set up" all my stuff has been set up by some very knowledgable gentlemen :wink: . Hummm No ride hieght adjuster on an Ohlin for a XX??? :shock: , I guess thats one for Penske!! :grin: :grin: :grin: :grin: :grin: Quote Link to comment Share on other sites More sharing options...
azxr Posted April 12, 2003 Share Posted April 12, 2003 Hummm No ride hieght adjuster on an Ohlin for a XX??? :shock: ' date=' [/quote'] Nope. I can reaffirm that. Quote Link to comment Share on other sites More sharing options...
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