Atlas Roadholder Fork Question

texasSlick

texasSlick

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I have just put new bushes and seals in my Atlas Roadholder forks and a problem has come up.

After installing the new top bush, paper washer, and seal, then tightening the slider extension (part-no: 06.0350), I have a 0.052" gap between the slider extension and the fork leg. This has occurred on both the right and left legs. Originally, the slider extension snugged up tightly to the fork leg.

I measured the flange of the top bushes, and found both the new and old to be 0.188", the width or thickness of the new seal was about 0.010 - 0.012" greater than the old, so that accounts for a small part of the gap.

The only other thing I have thought of is the inside radius where the flange of the bush meets the long cylinder, may be holding the bush from fully seating. I will have to pull the forks and disassemble everything to check this out.

Has any one else encountered this problem?

Slick
 
Checked on the only one close by. Left .020, right .040 gap between slider and the seal holder. I think there should be a small gap there. Otherwise oil will leak out between the bush and the seal, making it's way via the thread. Had a problem with that once, fixed it with double paper washers and PTFE tape on the thread.
A bit off topic, on the road going ones copying the Manx seal holders, I drill two radial blind holes in the seal holder, so I can use the Manx tool to tighten them.
 
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My '63 Atlas has about a gap of about .030 - 0.040" between 06.0350 and the slider. I replaced the bushings and seals a few years back with AN parts from Fair Spares. The forks seem to work just fine and aren't leaking.
 
I pulled one fork assembly apart, and installed the original top bush. I found it seated about 10 thou deeper than the new bush. The old seals went out with the trash, so I could not seat an old seal and make an overall measurement, but I had determined the old seals were about 10 thou thinner (top to bottom) than the new. Thus I can account for 20 thou of my gap.

The new bushes have a slight radius where the flange meets the long cylinder. I filed out that radius and picked up the 10 thou that was the difference in seating depth between old and new bushes.

Thus, if the seals were the same thickness as the originals, my gap would be in the same range as reported by Peavey.

I filled the gap with a cork washer to keep dirt from packing up in the gap.

Case Closed.

Thanks for your replies.

Slick
 
texasSlick said:
I pulled one fork assembly apart, and installed the original top bush. I found it seated about 10 thou deeper than the new bush. The old seals went out with the trash, so I could not seat an old seal and make an overall measurement, but I had determined the old seals were about 10 thou thinner (top to bottom) than the new. Thus I can account for 20 thou of my gap.

The new bushes have a slight radius where the flange meets the long cylinder. I filed out that radius and picked up the 10 thou that was the difference in seating depth between old and new bushes.

Thus, if the seals were the same thickness as the originals, my gap would be in the same range as reported by Peavey.

I filled the gap with a cork washer to keep dirt from packing up in the gap.

Case Closed.

Thanks for your replies.

Slick
Click to expand...
Sorry for the delay, but attached are photos of the gap on my fork leg. I last had this apart more than 10 years ago to fit new bushes. I remember thinking that the gap resulted from the thickness of the "top hat" portion of the bush. Unfortunately I didn't think of your elegant use of a cork or other gap filler, but the fork has functioned since rebuilt with no issue.
 

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Not to dredge up the past, but how do you guys favor tightening down the screw-in collars above the oil seal? I got them to hand-tight with grippy rubber gloves on, but am considering getting a strap wrench (to be used at the very base...)
 
IIRC the last time I did this I very carefully clamped the seal holder in a vise with jaws lined with thick plastic inserts and then tightened by turning the slider with a bar in the spindle hole. Obviously you can do a lot of damage this way if you're not careful.
 
I just do them up hand tight and have never had a problem with them coming loose, but I do use a bit of ptfe tape on the threads. Can't see a problem using a rubber strap wrench either.
 
These are the fork slider extensions, part # 06.0350.

Mine are drilled for a pin wrench, or a "C" spanner. Apparently, the newly made ones are not.

I would drill a 5 mm dia. (13/64") hole, about 5 mm deep near the base in each fork extension. Then with a 58-62 mm "C" spanner, tightening or removing them is a no mar piece of cake.

Slick
 
I was thinking of drilling for a hook spanner (as I always heard it called?) But was worried it would either tear the hole I drilled while tightening or lead to some other disaster...
 
AgentX said:
I was thinking of drilling for a hook spanner (as I always heard it called?) But was worried it would either tear the hole I drilled while tightening or lead to some other disaster...
Click to expand...

The fork extension is solid brass near the threaded end .... if you drill about 3/16" above the shoulder, there is plenty of "meat"; you should not have any problem with tear out.

Slick
 
You guys have lost me. What is a fork extension ? brass? Sintered bronze bush OK but I know of no brass in the front end at all...


texasSlick said:
It is more of a lock nut. See Item 20
Click to expand...

I think the terminology threw me
fork covers
1 head light/cover between the yoke,
2 cover below bottom yoke
3 inner cover ON nut and leg

2&3 (shorties) can hold the large diameter rubber bellows for featherbed or series 1 commando/fastback
 
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It is the Norton nomenclature for the collar that screws into the top of the fork slider above the oil seal and paper washer.
 
AgentX said:
It is the Norton nomenclature for the collar that screws into the top of the fork slider above the oil seal and paper washer.
Click to expand...
That's now what I think. The item is just like the commando piece except it is thinned on the top 90% for the tubing to be put on and the IIRC furnace brazed in place then chromed. The chromed tubing is what you would grip on with the vice grip 20C chain wrench (shown in commando thread). One set has the 4 hole around the side for a "C" type pin wrench
 
fork slider extensions, part # 06.0350.

Drill 5 mm dia x 5 mm deep for "C" type pin wrench

Atlas Roadholder Fork Question


Slick
 
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1. TOP: vice grip 20R on cut down fork seal holder, only one here with oil bleeder hole above threads like on slicks...probably really a 03-0454 not a 06 commando part

2. on left is long tapered internal seal holder screw, brazed joint 7/16 up on body, 4 drilled pin wrench holes .216"/5.5mm in main piece(not through sheet metal), I believe this to be an early one

3. on right: later seal holder covers brazed to body above .072" locating lip, no bleeder holes, later atlas? early commando?

4. plain jane 06.1137 steel commando holder not shown

Atlas Roadholder Fork Question
 
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For the record:

I think DynoDave is right ..... The early Atlas parts had 4 drilled holes for a pin wrench, then were superceded by parts having only 1 hole. My Atlas has one of each type ..... because I had a wreck in 1966 and had to replace one of the seal holders, or fork slider extensions as they are called in the current AN nomenclature.

Also, the pin wrench holes measure 0.216"/5.5 mm.

Slick
 

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