Suspension problems!

The front suspension on my 82 Maxim 750 seems to be too firm... on uneven roads (I'm in the UK :roll: ) it judders/bounces rapidly making the bike feel unstable. I don't know what the PO did when he changed the fork oil seals, but it doesn't feel safe at speed on bends, The dials on top of each fork are at no 1 (or 4 - I can't tell as theres no referance mark) - but adjusting these doesn't seem to make any difference anyway. I was going to try draining the oil and putting in 10w incase he used the wrong type.
The rear shox have a simple 5 position pre-tension adjustment, no air assistance and the ride is OK when set at 4 when solo (I'm 200 lbs), but with a pillion (+120 lbs) they bottom out and I need to turn them to 3 (firmer), but then solo the ride is worse and it doesn't corner as happily.
Tyre pressures are 28r 26f, the rear is a shinko, front is Metzler, which isn't a good combo, when riding along white lines its a bit wobbly, but my problems are at 50 -60+ mph, and I didn't think it would be the cause here - I've always ridden on a budget so usually have mismatched tyres. I checked fork alignment by loosening the front end and then bouncing and tightening from the top down
I could'nt find a guide for suspension in the forums, so has anyone any suggestions tips or comparisons for me please?

 

I would look to see if the PO has added Pre-Loads to the Forks to try and compensate for weak Springs.

Too much Pre-Load will cause the Springs Coils to "Bind" and touch-together.

New Progressive Front Springs along with Sliders, Seals and High Quality Oil will bring-back the Front-end damping and restore handling.

 

Thanks! Thats something I hadn't considered... As I'm going to drain them anyway, I'll pull all the bits out and check, I couldn't go as far as all that replacement at the minute - finances are pretty tight.

 

You might NEED a set of preload spacers, how far do they currently compress when you sit on the bike?

I agree that a fork oil change might be the first step. You never know what's in there.

 

If you want to check it properly check your "sag"

http://www.sportrider.com/tech/146_0308 ... index.html

Adding preload is a bandaid fix at best

A linear rate spring correct for your weight will be far better than any progressive "one size fits all"

 

OK, thanks for that, but I just want a safe comfortable ride - not tuning to race spec or anything like that. Most of my bikes have been set to the manual specs and that seems to work fine for me in most cases.