Shock length for 77 KTM

[Gippslander]

Am away from home so can't measure my bike.

Am looking at a set of shocks for the rear of my 77 250 KTM MX'r, anyone know the eye to eye length?

Looks the same as MauriceR's 77 MX5

Thanks

[Slakewell]

13.5 inch is about right. The Gazzi's pictured on my bike below are now available from Alan. You can also get works performance with hose remotes. If you fit Fox airs you need to cut and weld frame mounts.

[Gippslander]

Thanks Slakewell, I was lookin' at these

http://www.ebay.com.au/itm/251322605286?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

They look in good nick and I now know they are the correct length, but I will shy away because I do not want to mod the frame as you say would be needed.

My bike will not turn out as nice as yours, will be doing the racing only resto.

Gazi's will probably get the job, the only negative thing I've heard about then is that the shaft is too thick thereby reducing the oil capacity, other than that there only seems to be good reports.

And with me being 107k in gear I do give shock a workout but the races are usually only 3-4 laps so how hot can that get the oil, me thinks not to the point where the shocks would fail to damp properly.

Will ask you later about the shock spec you are running.

Thanks

[Slakewell]

Bill has a pair of Fox airs on his 77 and if you haven't painted the frame yet it doesn't appear to be a big mod. I did find that I preferred to run the Gazzi's at the shortest setting so it is under the 13.5
If you can find a set of 78 KTM Ohlins they are a good solution as well. The Gazzi's on my bike have remotes so I cant say I have noticed any fade or over heating.

[Brian Watson]

I have a pair of Marzocchi finned resi shocks , the same as came on the bike..I even bought a new set of shafts and seals etc from the USA.. when the shafts got here they are the 12/13mm shafts not the 10mm as came on the bikes.... with a bit of fiddling you could make them fit together... Interested..pm me..

[Grunter215]

So the original Marzocchi finned piggyback shocks were they shit / good / excellent? Is it worthwhile rebuilding with updated internals/re-valving etc ? Some tests  say they worked pretty good, so whats the general opinion.

[oldyzman]

That's a nice looking bike.
Brett

[Slakewell]

So the original Marzocchi finned piggyback shocks were they shit / good / excellent? Is it worthwhile rebuilding with updated internals/re-valving etc ? Some tests  say they worked pretty good, so whats the general opinion.

I have not seen anyone have success with them even after full rebuilds.

[ozktm]

I have just rebuilt mine, finding that the shims had been fitted incorrectly previously causing them to fail. Also, the small wave washer that holds the shims against the head had lost tension.
Now I have rebuilt them with another set of shims from spares that i had.
Filled with 10wt oil, and working very nicely.

Test time will be at crawford river classic to see how they handle a beating.

A good link on how to rebuild them : http://www.ducatimeccanica.com/marzocchi2.html

Something else to check is the spring/shim washer setup in the foot valve (#29 on the part list link above). If that has been spring is depressed when the shock is dismantled, the shim inside will move and not seat flush against the inside face. It takes some time to get this back in position, but can be done. I know this from experience...as you will loose dampening...

Adrian