New member

[redbanks2]

I just joined the forum. I am the original owner of a 756 that I bought new in '97. I tried a few demo rides on full suspension bikes and one ride on the Proflex was all it took! I do have a few questions for the experts. Excuse me for asking any old questions...My GDT rear shock has been leaking for a while. Can these be rebuilt or do they get replaced with newer ones. like the Risse air shocks? Has anyone added a rear disc brake mount to the swingarm? That's all for now. This forum is gonna be fun!

[kiwi]

the gdt can be rebuilt by cvi or noleen or if you watch ebaty you may be able to find a risse or similar.I too have a 756 mine was bought early 96 with the standard elastomers

[loaded]

I wouldn't bother getting your gdt rebuilt by a professional, they're dead simple on the inside, just dont mess with the stack of washers that control the dampening, keep em in the same order.
All you need to do is pull it apart carfully, check the seals and fill with new oil.  If your seals are cactus then you might be able to pick up some newones online somewhere, but I got some made by a local hydraulics company.  It took about 10 minutes with the materials they had and a set of snips, they can also help with o-rings, but  make sure the guy you're trying to get them off isn't busy cause they don't like wasting time with someone after two 15 cent o-rings.
Cheers [smiley=beer.gif]
Luke

[kiwi]

gdt arent just ods damping units.I beleive they are simple versions of a proper shock and require nitrogen recharghing

GDT shocks  The GDT shock ("Girvin Damping Technology") is a shock that was offered as an Original Equipment item on our 1996 and 1997 bicycles. It uses a similar technology to the Noleen shocks, but does not include an adjustable washer stack or any external adjustments. The GDT, however, utilizes a floating piston and performs well because of this feature. This shock was designed by Girvin engineers to be used on most of our 1997 lineup, but with the late-season purchase of Noleen, was spec'd on only a few bicycles and will not be sold as an aftermarket item.  ODS shocks  The Girvin ODS (Oil Damping System) was designed to work in conjunction with our MCU springs and provides the additional needed oil damping for the MCU shocks. ODS shocks are very simple shocks and do not utilize the same technological advances that make the Noleen shocks superior performers. The ODS shocks lack a floating piston, and therefore have a oil/air mix in the reservoir. They do, however, provide the limited damping required by MCU springs. Our experience has been that the ODS units function acceptably well when fitted with coil springs in the front only. "Clunking" noises and oil frothing are minimized in this application. Using coils in the rear, however, can and will cause improper shock function and is not recommended by Girvin. Many performance enhancements have been suggested by many people, but the only change that Girvin suggests be made to this shock is the replacement of the stock 30w oil to a SAE 10w or 15w oil, if so desired. Continuing to use the MCU springs on the ODS shock will yield the best performance from this simple damping unit

[Hammer]

Hi there,

HammerHead make a disc adapter to fit discs on the rear of a x56 frame.

You can buy these from

http://www.rapiddescentscotland.co.uk

There is a pdf document on thier site that shows the adapter.

http://www.rapiddescentscotland.co.uk/index.php?module=documents&JAS_DocumentManager_op=downloadFile&JAS_File_id=9

They also have spring and shock upgrades for Pro~Flex bikes.

Take it easy,

Hammer.

[Carbon_Angus]

yeah all it took was one ride on an 857 in a bike shop and i was hooked, too. put some of your history on the third threaded sticky from the top, if you wish.

glad to have you aboard. there is tons and kilos of knowledge and expereince here and no attitude,

no stupid questions either ..only redundant ones...with polite answers! [smiley=laughing.gif]

[smiley=beer.gif]

[loaded]

oops! Kiwi's absolutly right I was getting the GDT mixed up with the ODS........  

[kiwi]

oops! Kiwi's absolutly right I was getting the GDT mixed up with the ODS

thought you might have..the gdt were fitted to very few bikes,although there was a model called the gdt beast I think,a late model 6 or early 7....

[orange]

Is this the GDT that I'm bidding on?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7220395386&rd=1&sspagename=STRK%3AMEBI%3AIT&rd=1

[redbanks2]

Yes, the GDT rear shock on Ebay is the same that I have on my 756. It was put on a limited number of Proflex's before they went with Noleen. It is a great shock but not user rebuildable (nitrogen charged). Mine leaks and I need to replace it.

[orange]

somebody's outbid me now  [smiley=disbelief.gif] oh well...

[Colin]

Hi Redbanks2!  

You're in luck!

I have a Brand New, Never Used, Rear ODS Shock that I can sell you.

It's just the shock, i.e. no mounting gear, spring/MCU's, plates etc etc.

But from what you say, you're OK for everything else, so I think this is just what you need?

I guess the ODS might be regarded as inferior to a GDT, but a lot of us use them and as "loaded" says at least you can maintain them! and it'll be a lot cheaper than a Risse! Girvin only did the GDT for one Year, so I'm not sure if there's much support for them?

email me for a picture, price and postage costs to wherever you live (I'm in the UK).

colin.j.simmonds"at"bt.com

obviously replace the "at" with @ !! (hopefully to stop my email address being snatched off the site!)

Regards
Col.