FF: Forks FF3 Bottom link assembly dimension

[Cyborg]

I ended up using the press to get the eyes closer together as much as the gage would allow. Then pressed a bit more without the gage because of the spring back. Then used the vise to bend the arms to get the eyes parallel and repeated the whole process. Also used a pipe over an old spindle to remove a bit of twist. I had a bar of 6061 T6 which was turned down to a slip fit in the eyes. It was used for the final ( hopefully) alignment and now fits though both eyes with nothing more than a turning motion.
The arbor press in the background of photo 1 wasn’t used if anyone is wondering. The feeler gage in photo 3 is .008”. To get rid of the .008” it would mean bending the arms again, which in turn would mean I would have to realign the eyes so that they are parallel again. I think I’ll call it good for now and just live with the shame of putting a .004” shim behind each eccentric. As my avatar would suggest I’ve stocked up on shims since returning to the Vincent fold. Ever wonder if the motorcycles were just a front for their shim factory?
I laid it out on V blocks and it gets the green light. I still have to confirm dimension F is equal side to side or at least within normal shimming distance, whatever that might be.

 

[timetraveller]

Congratulations.

 

[Cyborg]

Congratulations.

Thank you,
I still haven’t poked a bore gauge into the eyes, but I’m fairly sure the one eye seemed out of round because of the twist. Now that everything is aligned… the way the bar slides in there suggests all is ok.

 

[greg brillus]

The bearing mod is only suited to the modified stem assembly not a stock one...........i just use 2 straight edges outside the large eyes and align them against the opposite end bushes, get these as best you can. The best way to align the two large eye ends is to have them honed by an engine reco shop that have a proper hone for doing connecting rods........This will get the 2 ends perfectly square to each other, then just buy or make up some oversized bushes to suit........ Cheers.

 

[Cyborg]

Thanks Greg. I know what you mean by using the hone and that would likely be the easiest way to make them perfect. I do hope that the fact that the bar slides in there with just a bit of rotation (to help the slip fit along), means they will be good enough. I will use your suggestion for the straight edges, but will likely wait until tomorrow. I want at least one day to bask in the glory. I’m still waffling about the modified stem, although leaning towards using one. The actual stem is already done and have the material for the bottom bit…. just have to machine it. It looks straight forward. As long as the mill is trammed to perfection and the block I’m starting with is square, it should be all good.

 

[Robert Watson]

Now just make new bushings exactly to size from Nylatron, (Moly impregnated plastic, quite common in industry for just such bearings) and then you don't have to fuss with shims.

 

[Cyborg]

Now just make new bushings exactly to size from Nylatron, (Moly impregnated plastic, quite common in industry for just such bearings) and then you don't have to fuss with shims.

Then my NOS Oilite bushings will haunt me.

Is there a local supplier? Davivd had mentioned some different material, but same general idea. Frightfully expensive and I couldn’t find a source for round bar.
I had a quick look at Nylatron and it sounds like it ok as far as not being too hygroscopic. Someone else mentioned nylon, which would be hazardous, especially for brake cam bushings.

 

[Robert Watson]

Then my NOS Oilite bushings will haunt me.

Is there a local supplier? Davivd had mentioned some different material, but same general idea. Frightfully expensive and I couldn’t find a source for round bar.
I had a quick look at Nylatron and it sounds like it ok as far as not being too hygroscopic. Someone else mentioned nylon, which would be hazardous, especially for brake cam bushings.

I did them in the Woolly eons ago, never seem to have absorbed any water, and trust me that thing has done mega miles in the rain!

Plus I know a guy that has some 2 in bar in stock. Going to be doing a set some time in the spring, or sooner.

 

[Cyborg]

I did them in the Woolly eons ago, never seem to have absorbed any water, and trust me that thing has done mega miles in the rain!

Plus I know a guy that has some 2 in bar in stock. Going to be doing a set some time in the spring, or sooner.

Nylon’s hygroscopic properties can drive you insane. This is a routine fuel tank reinstall after it swelled up up like it had gout.
Not sure exactly what formula they used for the tank, but it ain’t the correct one. I think some Ducati models were worse.
My V11 Sport tank hit the fork tubes when I first got it, so it went on a strict diet. No ethanol. It now clears the tubes.

 

[Robert Watson]

Well if you will mess about with them funny fuuren bikes, what do you expect??