Motoscrubs.com

I can't say whether you get a damper valve with a new stanchion, but if you can get the little wire clip out the damper should push out fairly easily. I found that a sharp knife with a pointed end on the blade could flick the end of the clip out of the groove and then you can get it out.

Fast from the Past sells Tarozzi fork tubes for Ducati singles. You might be able to remove the wire clip that retains the damper valve. More often than not, removal requires cutting a notch in the fork tube to get a tool under the clip in order to remove it.

Matt

I was able to get the wire clip holding the damper valve in place in the stantion, but not sure how to get the damper valve out. Should I be able to tap it out through the bottom?

With the ring removed the damper valve can be removed out the bottom of the stanchion. Tap the valve out with a long wooden dowel or broom stick from the inside. There is probably a burr or something keeping it from coming out. I’ve seen valves worn at the bottom by the snap ring and also some ball bearings can come loose and cause damage.

I looked around for fork tubes and it seems Widecase.com is the cheapest. You could try Frank’s Forks as well, you’d have to call them for a quote.

I don’t know of any sources here in the US for grinding and hard chroming fork tubes it’s just too expensive. I think there are more options like that in the UK.

A few places sell replacement valves but they are very expensive, hopefully yours are serviceable. I made a couple sets of valves a few years ago. If you have any machinist friends they could make a pair. I probably still have the cad file I made.

Aaron

Thanks Aaron. I got a quote on rechrome and grind, but it was $200/stantion. Shipping was of course extra. I am sure straightening would be even more. If you had something rare, it's a reasonable charge, but happy to get new and save.

I will attempt to tap out the valve, I think I have a pvc pipe at home that will work. I just hate to gorilla a part to death only to find out it wasn't designed to do what I was trying to do. Appreciate the guidance.

I looked up widecase.com, interesting website. I may just order from Fast from the Past since they have them in stock and are in the US.

I ordered new stantions from Fast from the Past. They are direct replacements. The only issue that I encountered was that one of the stantions was not ground to as tight of a tolerance as it should have been on the bottom inch of the stantion, and would not go into the fork tube. The entire length of the stantion except the last inch was a perfect 31.5mm. The last inch was 31.55. The extra .05mm was enough to prevent it from going into the fork tube. It took me a little while to discover the problem was limited to the bottom inch of the stantion.

I was able to remove the excess material by hand but It took me a while since it didn't want to go at it too aggressively. I used 400 - 1000 grit sandpaper and an scotchbrite pad. I also polished the stantion with polishing pad/machine. Hardly machine shop precision, but I must have measured the thing 100 or more times, so am comfortable with the result.

The other issue that I encountered was that some grit had worked it's way past the seal and scored both the old stantion and the fork tube. I have ordered a brake cylinder hone and intend to clean it up to ensure smooth operation. I will be careful not to be too aggressive and remove too much material to cause too loose of a fit.

I am glad I did this project, definitely overdue.

Okay, I'm changing my diagnosis. I am done 'sanding' the fork stantion. I am able to run a 31.5 caliper down the tube and other than a very slight resistance in the last quarter inch, it seems to be perfectly uniform. However, I still could not insert the stantion all the way into the base. Hmmm. I ran the hone down up and down the inside of the fork bottom, but still could not insert the stantion. I finally swapped things around. I took the stantion that I successfully inserted in the other fork tube and found that I could not insert it into this fork bottom. Also, I could successfully insert the stantion that I have been sanding into the other fork bottom.

I therefore seem to have a bent fork bottom. Does that seem to be the correct diagnosis? I could buy a new one, but this one has the date stamp on it, so I am thinking I may have it machined to keep it original to the bike. Does anyone know the correct inside diameter of the fork bottom? Does anyone have another suggestion for a next step? I don't think honing will work as I will only be widening the bend, not fixing it. Would it be wider to bag originality and just get a new fork bottom?

Thanks.

Greg

Sorry, I promise not to keep responding to my own posts, but thought I would share a little more progress. I started to remind myself that manufacturing in 1965 Italy, and probably lots of other places, was somewhat crude. The engineering was amazing, but this was not an ISO 9000 factory and there were no CNC machines. I guess that the worker picked up a stantion, which would have been close to 31.5, then honed the fork tube to fit that one stantion. Once it fit, they were done with the pair, therefore, it's quite possible that the two fork bottoms could have a slightly different interior diameter.

I went back to honing the fork bottom. I swapped my 20v drill for an older corded drill that would operate at higher RPM's. I applied some cutting oil to the surface and presto, the stantion now slides all the way into the tube. I still have a little more cleanup, but feel comfortable that I can make this work nicely.

Case closed.

I'm with you on this, it is possible to try to get everything perfect, but maybe when building a bike for racing that is the correct thing to do, but for a fun road bike 'good enough' must be the sensible way to go.