Parts for forks

[peteremc]

OK, been waiting patiently and received my fork tubes back this morning all nicely re-chromed - beautiful! Reassembling my forks today and keen to get a front end in this bike. All parts cleaned, new seals, new red rubber top stops obtained (and ready to start the process of disintegration inside the forks).

I will say that along the way I learned a great trick about compressing the rings and re-inserting the damper piston, which, otherwise would have been a monumental PITA. Slipped both in on second attempt and pretty proud of it.

But, I have a problem with reassembly. The valve housing (# 21 on diagram above) will not insert into the bottom of one of the fork tubes. One slipped in fine and is all together. I have pinned down that the inside of one of the fork tubes is out of round because I've tried both valve housings in both fork tubes, and both housings slip into one tube just fine, but neither will go into the other tube.  

The damper rod assembly all came out really easily so didn't seem to be problem when I dismantled. I've looked for a lip or burr on the fork tube that may be a result of re-chroming, but nothing there.

So, it seems like I'm off to my favourite engineering works (to spend even more $$$) to have the fork tube inside machined to round again. My question is, how careful do I have to be with this? Does the valve housing need to sit snug inside the fork tube, or is it OK if it might end up a tiny bit loose (laterally) and might turn inside the fork tube? I know that shims might be required lengthwise to stop it rattling, but is any lateral movement a problem?

[Bob_Roller]

You can insert the housing from the top, if it won't fit through the bottom .

I had this problem with one of the forks on my '82 LS .

[peteremc]

I wish it would, Bob but on my forks it has to come in from the bottom.

Looking at the fork tube from the bottom, there is a section of the tube which is just the right diameter and length for the housing and the washer above. Above this it reduces in diameter to take the piston and rings snugly. The housing is therefore held in place above by the shoulder where the tube becomes narrower and held in place below by a circlip at the bottom of the tube (which may require shims if the assembly rattles – mine does not). Besides, when reassembling, the piston end of the damper rod has to be inserted before the housing coming in from the bottom.

This is, indeed an ’82 LS, but I understand that the factory put out several different configurations of the forks even in the one year, which may explain the difference between yours and mine.

I have just fully assembled the other fork and on looking at the whole damper rod assembly in place, I think that a tiny bit of lateral play in the housing probably won't do any harm.

[Barry]

My question is, how careful do I have to be with this? Does the valve housing need to sit snug inside the fork tube, or is it OK if it might end up a tiny bit loose (laterally) and might turn inside the fork tube? I know that shims might be required lengthwise to stop it rattling, but is any lateral movement a problem?

I doubt it's critical to the nearest few thou as long as it remains reasonably concentric. The only time that really matters is when the forks are on full compression and the top hat damper rod seat enters the bottom of the valve body.  On assembly you should in any case push the fork leg up to maximum compression and rotate it a few time to centre things up before tightening the damper rod bolt.

Curious how the stanchion bore ended up a smaller diameter.  They didn't plate the inside did they ?  I can imagine that causing problems with the damper piston rings.

Assuming it's only a few thou that needs to be removed you could just as easily turn down the outside of the damper valve body and you might more easily contrive a way of doing that at home without a lathe.  

On the endplay I wouldn't accept anything more than one or two thou as the oil film will stop that chattering.  Mine I think was 20 thou and shimming produced a significant reduction in fork noise.

[peteremc]

Thanks Barry, and I'm with you. I don't think a few thou will matter greatly. The stanchion bore is not smaller, it is just ever so slightly out of round. Like I said, the old assembly just came out no trouble so maybe the chromer has done something. The chrome job is excellent and stops at the right place, so this hasn't impacted.

I said my other fork is fully assembled but I struggle with how to get the proper torque on the damper rod allen head bolt. Seems to need some compression to stop the damper rod from turning. You say to compress the fork to maximum compression. Will this allow me to tighten the damper rod bolt? Both manuals I have skim over this point in the reassembly process. Do you have a method for doing this off the bike?

P.S. I admitted up front that I was a novice at his game, but I'm learning a lot as I go.

[Barry]

I said my other fork is fully assembled but I struggle with how to get the proper torque on the damper rod allen head bolt. Seems to need some compression to stop the damper rod from turning. You say to compress the fork to maximum compression. Will this allow me to tighten the damper rod bolt? Both manuals I have skim over this point in the reassembly process. Do you have a method for doing this off the bike?
 

Although it can be done by compressing the fork leg the proper method with springs out is to hold the damp rod still from the top using a socket and long extension.

[nhmaf]

+1, Time to make a trip to your favorite hardware store and get the longest socket extension they have... or (2)... this is part of the "airhead maintenance initiation"!

[montmil]

+1, Time to make a trip to your favorite hardware store and get the longest socket extension they have... or (2)... this is part of the "airhead maintenance initiation"!

About a 14-inch extension and the correct socket will do it.

[Barry]

My socket set has a couple of extension that put together are long enough.  Given an adapter no reason why a 3/8" and 1/2"  extension couldn't be combined.

[peteremc]

Thanks all. It all sounds so logical when you can tap into the voice of experience. I hadn't even considered this as an option but it's a beauty. And I'm almost certain I have the extensions to do this. Thanks!

[Luca]

Those old Boge shocks kicking around on the floor... they're not holding the bike over the rear wheel are they?  

[peteremc]

There's your answer.

[peteremc]

Now you have me thinking. I really can't recall what they were like when the bike came off the road a few years back, and as I have no recollection of them being really horrible, I was just going to tidy them up, put them back on, and use them. Now at the risk of starting a "what is the best shocks/oil/tyres"-type discussion, if these (I assume stock) shockies are pretty bad in the scheme of what's available I really would like to know. Then I can look around for options.

What the hell, I've blown the budget anyway!!

[Luca]

I took Monte's advice and bought a set of Hagons from Dave Quinn.  They were about $230 including shipping.  He sprung them at the factory rate, since that will give me an inch of sag at 220lbs.  He can put whatever springs would suit you best in your set.

I've noticed a definite improvement in turning.  Then again, my Boge's were starting to make crunchy sounds.  I still think this is the best the bike has handled, and my back tire is getting pretty squared off.

[montmil]

I took Monte's advice and bought a set of Hagons from Dave Quinn... I still think this is the best the bike has handled, and my back tire is getting pretty squared off.

"Squared off" you say? More turns, less straights.

I like the way Dave Q sets up the shocks when you tell him, honestly, your ATGATT weight and a few other answers. For the price, they provide excellent control for our Airheads. Also available with spring shrouds, if you like that look.