Betor Damper rod modification

[grouty]

I have a set of Betor damper rods that I am using in a project. The forks as is, have a tiny bit too much of travel and just hit the front guard. I need to reduce the travel by about 10mm.

I really need to be able to remove the alloy piece at the lower end of the rod. How does this come off ??
The other way would be to remove the swiveling seats at the top of the rod. But it looks like these are permantly fixed.
Any suggestions would be helpful......

[flower pot racing]

put an extra (or longer) bump stop spring in to restrict the travel?

(or go slower!)

[grouty]

Go Slower .....  Mark is always telling me to go faster 
Even if I was to replace the bump spring Ben, how does the end come off. I am guessing it is just a sliding fit.
Ideally I would like to make a 10mm thick washer to sit atop the "valve" or alloy bit at the bottom of the rod.
I have a PDF and a Word file here with the diagram, but for the life of me cannot get it to appear here.

[flower pot racing]

mmm yes a picture would help to see what we are up against

[grouty]

I have the picture here in a "Word" format, as well as a "PDF" file. There does not seem to any way I can convert it to a media file to post via Photobucket.
If I could save them as a Jpeg, it would be easy :-(

[flower pot racing]

are you talking about the bit on the end of the rod that the damper bolt goes into?  
The damper rod is a constant section then gets bigger at the bottom.  Is this what you mean?
That bit is a press fit onto the damper rod.  

Stick a bolt in the damper rod, clamp the main shaft in a vice so that it can float up and down, then with the bolt head pointing upper most let the whole assembly slide through the clamp until it rests on that oversized piece attached to the damper.  With the bolt 20mm engaged in the thread tape the head of the bolt to drift the rod free from that end piece.

Stick a longer spring in then reassemble.

.............

I think that is the problem you are describing.  Pics would help.  Dont start hitting anything until you are sure!

I have some on the bench at home.  I can email you some pics to show you what I think you are describing if that would help.

PM me your email address or send a note to me at home

cheers
F P R

[grouty]

Thanks Ben.

Yes, it is the alloy end that accepts the damper bolt at the bottom. It looks like it is pressed onto the steel damper tube. But, like you say, I want to be sure before I "gently persuade" .
Pictures of your disassembled ones would be good.

[grouty]

Done it 
I knew if I thought long enough I would figure getting theis picture on here.


The bit I want to remove is #35 in the large picture.
A close up of that part is the lower picture.

[Montynut]

The same forks are used on Montesa bikes of the early 70s and all the ones I have taken to bits except one the alloy bottoming cap (part 35) just slipped off and were not a press fit.

The one pair that would not come apart seemed to be basically glued on. I don't know if someone had covered the whole lot in loctite or if it was some form of residue from oil but I had to heat them gently and finally they came off. I inserted the damper rod back into the fork tube about half way then gently heated the stuck area then fully inserted the damper rod until the alloy bit (35) bottomed in the tube with a bolt partly inserted in the damper rod through the alloy part. Then tapped the bolt and the damper rod came out of the alloy bottom section.

Naturally the heating destroyed the seal at the bottom of the damper rod (part 34) but that is just a fibre washer basically.

Not sure if I expalined that very well. Hope it helps

[flower pot racing]

It is as I have described.

I guess you get a bit of hydraulic lock in there with a build up of film of oil, crude etc.

tap them off as I have described.

[grouty]

Thanks for your help guy's. All apart.

I have sent you an email Ben. If you have a spare second hand part #33 above, I can part off two 12mm long pieces to make the spacers I need.

[Freakshow]

what year are these betor go back to as this style ?

[SPANISH ARMADA]

hard to get all that freaky but if you mean what year can they be used for they r pre 65 legal and the triples also cheers

[Freakshow]

Cool that was the question, have a set here just wondered what I can put them on.