suspension tech question old school advice needed !!

Started by zookrider, November 18, 2007, 10:09:33 PM

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zookrider

1992 suzuki bandit 400 (remember those ?) Would like to replace the stock handlebars with some nice clipons I've got. I'll need to raise the fork tubes about 1 or 2 inches above the triple clamp to make it work. Forks have been upgraded with progressive springs and longer spacers so I'm not worried about bottoming out.Nothing will rub or hit as these are conventional forks not USD"s. What I am concerned about is changing the rake/trail too much that it will cause unstable steering issues. Any advice on this one would be greatly appreciated

Super Dave

Will the headlight mounting brackets allow you to use the clip ons below the triple clamps?  That's the easiest way.  Might require that you replace the OEM holders with something aftermarket that can move so you can do it.

Nosing down the front end that much will certainly affect the geometry and the weight bias.  Given that you have the correct rate from Progressive, you would have more weight forward on the bike by moving an inch on the tubes. 

Maybe that gives you some ideas.
Super Dave

zookrider

The headlight brackets could be modified slightly to accommodate the clipons but I"m not sure I want the bars that low cause I'm an old man with a bad back :biggrin:.What I think may be to my advantage is the fact that the rake/trail on this bike is probably a few degrees more relaxed than most current sportbike designs. Thanks for the tips :thumb: Any other thoughts are certainly welcome!

Super Dave

You'd be surprised how little change there is in chassis geometry even over a long period of time.  I've raced some old bikes, and the geometry isn't bad on that stuff.

If your back is a problem, you might just want to stay away from clip ons.  They are going to have a downward angle regardless of the height.  Might be something to think about.  There are a hand full of people that are putting upright bars on SV650s even.
Super Dave

grasshopper

Just put some clubman bars on that bad little hot rod.

tzracer

When raising fork tubes a couple inches you may run into clearance problems.

Did you check?

The best way to determine the max amount you can raise the tubes is to remove the springs and  raise the front wheel as far as possible. Te distance between the fork slider and the lower triple clamp will be the maximum additional amount you may be able to raise the tubes. Move the tubes, then recheck to make sure the front wheel/fender cannot strike anything. I have seen front wheels hit frames/engines/exhaust pipes. Not a good thing while you are riding. I have also seen front fenders catch on parts and prevent the front wheel from rebounding. Do not guess, check how much you really can move the fork tubes.
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Keith Hertell

Quote from: grasshopper on November 19, 2007, 11:36:57 AM
Just put some clubman bars on that bad little hot rod.

Exactly!!! These are just like clipons but cheaper. Way back when, most peeps used these anyways.