saggy bottom

[jerry]

my M750 rear end seems saggy but the shock is not leaking its the original sachs unit still looks new after 20,000miles , cant find anything wrong with it at all so should I increase preload and or ride height ???? new shock is out of the question at the moment ???

[Paul_]

I assume you are running the same settings as you always have?

I think after 20,000 miles it is time for a shock refurb, it will be a little tired and in need of some TLC. Not sure on prices or who does them though, can anyone else help?

[Diego]

time for a new shock. refurbs on older sachs springs are a waste of time if you ask me ;-)

http://www.pdq1.com/result.php?CatID=4434&MakeID=7&ModelID=423&Year=0

ask for a black spring as they come in different colours

[jerry]

settings are the same as always since I last set the shock up and K tech and Falcon suspension ltd told me the Sachs unit are actually very good and can be refurbed for about £130 but unless it had leaked it was still OK

cant afford a new one just now and I would prefer tp buy Ohlins but they are now extortionate ,I like the Nitron qualty and price but not the spring colour, its horrid

[rac3r]

My bikes done just over 20k so looking to refresh/replace my suspension. Trying to save up for a Nitron shock, they sent me a price list and the sport one costs £295+VAT+£12 shipping. Set up for your weight blah blah blah. I found Nitron were the cheapest

(Nitron were set up by ex Ohlins workers, or so someone told me :chuckle:)

[utopia]

If anyone's after a Nitron, HPS have been doing a half price christmas deal for the last two years on the remote hydraulic preload adjuster, which is damn useful if you ever carry a pillion.
They may well repeat it this year.

[jerry]

yeah but that awful spring colour , I willask them if they can supply yellow .

[rac3r]

I actually don't mind the spring colour :chuckle:

[utopia]

I quite like the turquoise spring too....but you can specify black if you like.

[Mr Cake]

http://www.e4.com/images/mb/E4/bo-selecta/big.jpg
Can I getta reeeeeeeeeevalve!!!!!!

Phew! From the title I thought it was another "one for the ladies" thread.

Get yours serviced, it'll be ace after that.

C

[jerry]

they told me the spring can be powdercoated to any colour so maybe I will get one next year .

[jerry]

Well i have sort of cured the problem took out the old shcock and checked it carefully its all intact and perfect but the preload rings had somehow backed off !!!!!!!!!so I tightened them up about 2 turns and relocked them and put the shock back on and now all I OK handling is now perfect again......and no money spent ,

weird eh???

[utopia]

Following your original post, I was going to say that "sagginess" sounded more like a issue with the spring than with the damper.
I couldn't think how that might be though cos, like you say, its weird that the preload rings should back off by themselves.
I did wonder whether the spring had somehow weakened (though that seemed unlikely), or even if it had cracked (happened on my Astra estate), but that seemed unlikely too and I thought you would have spotted it anyway.
I guess it could be an issue with the spring seats, but again I would have thought you'd spot that fairly easily.
Anyway, you seem to have found the problem now so I guess all's well that ends well, although its still a bit odd so might be worth keeping an eye on.
I have the original Sachs unit from my 2000 M750 in a box under the bed where its easy to get at, so if you'd like me to check anything against your unit then just post up. Mine's only done 4 or 5k, so it should still be in pretty good nick.
Something to ponder......The preload adjuster on my Nitron unit has a square-form thread, rather than the vee-form of the original unit. This would be stronger than the original, but I wouldn't have thought it would make the preload setting much less likely to back off. However, the Nitron has no lock-ring at all, just a single adjuster ring. I've noticed no problem with the preload adjusting itself though (in about 5k miles use), which makes it even weirder that yours should do so, with its secondary lock-ring.

[Starter Sprag]

You could always thread-lock the nuts, once you're happy with the setting

[utopia]

ps....on my 2000 model, spring free length (ie at zero preload) should be 185mm.
Std preload setting is 20mm.

[jerry]

Speaking to various suspension gurus ,its very unlikely that the spring loses much tension apparently,, I last set preload 3 years ago on this bike but have never known the rings to get loose before , so i will check all my bikes for this issue regularly , i also have a spare S4 shock which I am told will also fit M750 so i might try that on in the spring .