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Discussion Starter · #1 ·
As the title suggests, I want to raise the rear ride height on my 99 M750. I use it as a race bike only, and the poor Sachs shock is way undersprung, so the suspension is compressing far too much under cornering load. This is reducing the ground clearance... a lot. I'm hanging way off, yet the exhaust/ pegs are touching down and I still have CHICKEN STRIPS on the rear tyre :p
Just incase anyone is curious, i weight about 90kg (200ish lbs) in my riding gear and the rear pre-load adjustment is maxed out.

I am looking at an after market shock when finances allow, but for the meantime I want to just jack the rear end up a bit.
Forgive my lack of the correct terms here.....It seems to me that the obvious solution is to use the eyebolts at the end of the ? shaped push rod(?) that attaches to the rocker arm (the other end of the rocker arm is attached to the top of the shock). They are threaded and have a lock nut, so I'm assuming that there is a small amount of adjustment available. Or I could just by longer eyebolts.

Anybody done this? Is this their intended purpose?
 

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It seems to me that the obvious solution is to use the eyebolts at the end of the ? shaped push rod(?) that attaches to the rocker arm (the other end of the rocker arm is attached to the top of the shock). They are threaded and have a lock nut, so I'm assuming that there is a small amount of adjustment available. Or I could just by longer eyebolts.

Anybody done this? Is this their intended purpose?
Yes, just unscrew them, 12-14mm is possible. Makes quite a dramatic change
regarding steering, weight forward etc so be careful first ride. Maybe try just
6 mm first time and see what you think.
It`s a good thing, lotsa riders & me dunnit.

And yes, that`s the bolts purpose, adj rear ride height.

Until you can afford a good shock, buy a spring for your weight.
Makes a noticeable difference and you just transfer it to the new
shock when you buy it. Dunnit, it`s good.

You could also push down forks in your triples to get better ground clearance.
 

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You can add about an inch to the rear by making the rear adjustment described above. You should be able to get a little over half an inch on the front by sliding the forks down until they're level with the top triple clamp.

If you're using the bike mainly for racing, you should buy a stiffer spring right away. They're not that expensive. A new spring shouldn't be more than about $100, although I'm not sure where to order one online, or even what your current spring rate is. I would call Aftershocks Suspension in Palo Alto, CA to see if they'll sell just the spring and what spring rate they recommend. Actually, since I live close, I would take the whole shock there and have them fix it for me. Check out their prices. They do excellent work. Total cost is on the order of the price of one track day.
 

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Discussion Starter · #4 ·
Sweet as! Lowering the forks in the tripple clamp was going to be my next question, so I'll be doing that too.

And yep, I'm trying to source a stiffer spring. My only concern there is that the rebound damping is already on the second to last click. Not sure if it'll cope with a stiffer spring, I'll talk to the local suspension guru and see what he thinks. He'll probably suggest servicing the shock and messing with the valving and oil weight.

Anyway, thanks!
 

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TonyB said:
As the title suggests, I want to raise the rear ride height on my 99 M750. I use it as a race bike only, and the poor Sachs shock is way undersprung, so the suspension is compressing far too much under cornering load. This is reducing the ground clearance... a lot. I'm hanging way off, yet the exhaust/ pegs are touching down and I still have CHICKEN STRIPS on the rear tyre :p
Just incase anyone is curious, i weight about 90kg (200ish lbs) in my riding gear and the rear pre-load adjustment is maxed out.

I am looking at an after market shock when finances allow, but for the meantime I want to just jack the rear end up a bit.
Forgive my lack of the correct terms here.....It seems to me that the obvious solution is to use the eyebolts at the end of the ? shaped push rod(?) that attaches to the rocker arm (the other end of the rocker arm is attached to the top of the shock). They are threaded and have a lock nut, so I'm assuming that there is a small amount of adjustment available. Or I could just by longer eyebolts.

Anybody done this? Is this their intended purpose?
Here you go................... [thumbsup]

http://www.ducatisuite.com/rearheight.html

Oh, and if you can swing an Ohlins rear shock you'll love it! I have one my 99 M750 and it's sweet.
 

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Discussion Starter · #6 ·
Thanks Stu. I'll let you all know how I get on, probably not racing again till Feb, so it may take a while.

Yeah an Ohlins is definitely on the wish list, but considering I paid NZ$3900 for the bike and the shock is $1450.... Mind you, the shock will have the correct spring weight, a height adjuster, and will be revalved to make it work on bumpy low grip NZ tracks
 

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I'm trying to source a stiffer spring. My only concern there is that the rebound damping is already on the second to last click. Not sure if it'll cope with a stiffer spring,
Rebound will work. You probably have too much now,
just to calm the bike`s rear down abit.
I had mine 2-3 clicks futher out w after the spring switch.
It will almost behave like a real shock w a good spring... ;)
Öhlins have springs for Sachs, later it will fit your Öhlins.
 

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Discussion Starter · #8 ·
I FINALLY got around to doing something about this today. The ride height was set at the lowest setting possible without taking off the lock nuts. Working on the 10mm thread rule I raised the rear end about as high as it can go- measured at the end of the OEM exhausts, and with me on the bike, I ended up with a 20mm lift. At the pegs it equated to either 10 or 15mm (forget which). I have left the forks where they are for now, though I guess I should really drop them down through the triple clamps so the front end is lifted too- looking at it the most I can hope to get is 10mm lift, so overall the steering should still be sharper if I go ahead and do it.

Haven't had a chance to ride it yet- its a track only bike. I took some rough sag measurements - from unloaded to loaded* 42mm rear and 34mm front, so it's too soft at both ends. For starters I thinkI'll go for new springs at both ends and see how it feels.
* IE wheels off the ground = unloaded. Me sitting on it = loaded.

Thanks for your help guys!
 

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Discussion Starter · #9 ·
Well, without even riding it to see what it was like, I decided to go with Scott R's advice. I've pulled the shock and the forks off and I'm sending them off to have some nice new Ohlins springs put on/ in. The forks will be tweaked a bit with heavier oil, the shock will just get a spring. Hopefully that will give a resonable improvement.
 

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Discussion Starter · #11 ·
Haven't got them back yet- I could have if I'd been in town. Oh well, next week.

I just thought some of you might find the suspension guys report interesting. Bear in mind all I had him do is throw some new springs on and put some heavier oil in the forks. I asked him not to put any time into the shock with a dyno analysis etc. He hasn't had the forks completely apart:

Improvement is a term of relativity, what I have done will make a substanial improvement. The forks are very crude, they have what feels like a check plate type cartridge. There is basically no compression damping except at the very bottom of the stroke to afford some hydraulic bottoming out control. Rebound is a big compromise, I have installed a heavier oil to afford some degree of mid and high speed rebound control, but if you go too far it messes up low speed rebound shaft speed. These are Italian Marzocchi forks, the later models have Showa. Whilst the Showas are still crude the internals can be respec'd at moderate cost, not so with these.

The shock had absolutely no gas pressure so I have regassed it ( that is not a stripdown ) On the manual push test ( minus spring ) it feels tired.
 
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