1966 Scrambler Fork question

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Rickytic
Cucciolo - the Lil Pup
Posts: 14
Joined: Sat Sep 13, 2014 3:33 pm

1966 Scrambler Fork question

Post by Rickytic » Tue Dec 09, 2014 1:26 pm

I am currently restoring a 1966 250 motocross scrambler. Upon taking the first front leg apart, I noticed most of the little 9 - 1/8 " ball bearings that go in the lower leg bottom are missing, only 2 are present, the other 7 are MIA and I am guessing they are powder and part of the sludge that I am pulling out of the tube.

My question is, what is the function of those little bearings? I have searched the site and can find nothing on this.

Thanks in advance for you knowledge.



Rickytic

Rickytic
Cucciolo - the Lil Pup
Posts: 14
Joined: Sat Sep 13, 2014 3:33 pm

Re: 1966 Scrambler Fork question

Post by Rickytic » Thu Dec 18, 2014 8:49 am

Somebody out there must have an answer, or theory!!! I am really wondering if I need to put the ball bearings back in and figure a way to secure them or can they be left out. Guess there is supposed to be a washer covering them and then some kind of slip ring to hold the washer in, just don't know. When I took the fork apart, no washer, no ring, and just a couple ball bearings left in place. Would like to find something out soon from somebody that has previous experience so I can start putting the forks back together, with or without the bearings. Help me out here.

ducadini
750 Sport [BEVEL]
Posts: 217
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: 1966 Scrambler Fork question

Post by ducadini » Sat Dec 20, 2014 1:11 am

When working on +50 year old stuff (those forks were used earlier also), no need to rush anything or anybody.
Not everyone has constant access to the net, and even fewer know/remember anything about these things.
Even I occasionally tend to take the easy way and start asking around, instead of sitting down, observing the parts and try to figure out how it works.
Since You already figured out there are 9 balls each fork, and only found 2 in one fork, You've got both dismantled and one in working order :-)
Could it be there is a drilled washer under/over them to act as a hydraulic brake/damper ?
There are 9 (each fork) 5/32 (you were close) balls ( 3.96 mm RIV90152005), fitted in what the partslist states as : "soupape/valve" (damper valve)
Sadly the partslist isn't too accurate about it's placing and/or other adjourning parts so You'll have to figure that out for Yourself.

I have a earlier scrambler here, but the forks are not to be dismantled (yet).

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

Rickytic
Cucciolo - the Lil Pup
Posts: 14
Joined: Sat Sep 13, 2014 3:33 pm

Re: 1966 Scrambler Fork question

Post by Rickytic » Sat Dec 20, 2014 9:49 am

ducadini wrote:When working on +50 year old stuff (those forks were used earlier also), no need to rush anything or anybody.
Not everyone has constant access to the net, and even fewer know/remember anything about these things.
Even I occasionally tend to take the easy way and start asking around, instead of sitting down, observing the parts and try to figure out how it works.
Since You already figured out there are 9 balls each fork, and only found 2 in one fork, You've got both dismantled and one in working order :-)
Could it be there is a drilled washer under/over them to act as a hydraulic brake/damper ?
There are 9 (each fork) 5/32 (you were close) balls ( 3.96 mm RIV90152005), fitted in what the partslist states as : "soupape/valve" (damper valve)
Sadly the partslist isn't too accurate about it's placing and/or other adjourning parts so You'll have to figure that out for Yourself.

I have a earlier scrambler here, but the forks are not to be dismantled (yet).

ciao
ducadini
Ducadini, thanks for your response,
Prior to asking on the forum, I looked at the schematic, read articles on how to rebuild these forks, and had several motorcycle type friends come over to look at them. It appears that all the parts are there and we know what order they go in when putting the pieces back together. The only thing we can't figure out is when the sliders go up and down, what holds the little ball bearings in place. When I took the sliders out, at the end of the slider you could see indentations where the balls came out and were laying at the bottom and caused indentations in the end of the slider. I believe the sludge that was in the bottom was in part powdered balls that got beaten to death. You are right about the parts list not being as accurate as it could be. Once I get this figured out, I will probably write an article on rebuilding this type fork so others can better understand.

Sorry if I sounded short and in a hurry, not my intention. I am new to this forum and guess there are not as many rebuilding these old Ducati types. I completed a frame up Honda 305 CL77 scrambler earlier this year and was able to get answers to questions when needed very quickly on the Honda 305 forum.

Again, thanks for your help, if you hear anything, please keep me in mind, and I will continue to research and fabricate if need be to get the forks right.


Rickytic

ducadini
750 Sport [BEVEL]
Posts: 217
Joined: Sat Jul 31, 2004 8:54 am
Location: Antwerpen

Re: 1966 Scrambler Fork question

Post by ducadini » Sun Dec 21, 2014 5:40 am

Rickytic,

no offense taken :-)
I know some people who know people who have designed and fabricated those forks.
Trouble is : they don't to use the internet but prefer to communicate italian way : face to face and preferably with the stuff nearby so they can see what happened.
Since this is a technical issue that will affect me directly (whenever I get the chance to tackle the forks) there will be some close scruteneering by me of italian fora about these forks and giving additional feedback.
Also keep in mind that when You're rebuilding old stuff, You probably aren't the first who dismantled it, so the error could be from someone else .
If needed, i can scan some pages from the Monza/Diana partslist, just pm me.

Why didn't i just keep the Honda Dream I once found and stayed in the japanese classic scene : much easier :-) ??

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

Rickytic
Cucciolo - the Lil Pup
Posts: 14
Joined: Sat Sep 13, 2014 3:33 pm

Re: 1966 Scrambler Fork question

Post by Rickytic » Mon Dec 22, 2014 8:33 am

Thanks again, Ducadini.

I talked to the previous owner,(close friend and first/only owner of the bike) he says the forks have never been apart. Thanks for the offer to send parts schematics, would love the information if it's different than the ones I see in the parts catalogue and maintenance manuals. I have the parts diagram, and parts list, maybe I can take some pictures of the parts I have and post them or PM you with that. Upon looking at parts, the only conclusion I can come to at this time, is that the fluid may put enough pressure on the balls to keep them in place. When I took the forks apart, the seals had been leaking and there was almost no fluid in the tubes.

Again, thank you.


Rickytic

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