Fork spring compressed length

Btw just measured the Convent kit Al top bush hydro stop restorer, loose to fall to bottom of stanchion ankles collar = 1.252" long.

Jim,
I can't answer the question, sorry but regarding your turcite fork bushes I will get some soon. What would the turcite be like as replacements for the isolastic side wear pads? Might be better than the standard? Water has got into my front mount and rusted the steel to the original slipper. I might try and make/source some stainless iso end bits?

P.S. almost ready to try out those pistons you sent a little while back.

Richard

Clearer now?[/quote]


It is almost clearer. I have a completely machine sectioned away demo commando fork leg assembly to be able to give tech sessions and view the components in real world and then when installed with a commando triple tree with commando clock holder/washer, on mine it does not measure out that the spring goes coil bound.

http://atlanticgreen.com/forks.htm[/quote]

Hi dynodave,
I have returned to home base and measured the leftover spares I have on hand, verified them in the modeling database and reconstructed the model to see enough to stick to my guns.
I did visit the site you linked and don't see any data on the spring.
Here is my compressed spring data:




because most of my data comes from parts that are currently assembled into the motorbike I can't easily go any further in verification at present.
As far as I can tell the parts are all OE without modifications.
It's possible we are in possession of different revisions of various items and since I share in your passion for accuracy will go silent on this subject unless prompted until I need to disassemble the forks again. Thanks for your comments.
All the best.

AntrimMan said:

from stock MKIII that I actually measured on a threaded rod, .170 +/- wire, .980 OD, 13.465 solid, 18.575 free.

Click to expand...

I just did the same, and the spring went coil-bound at 13.25" from 18.575" free, an increase of .215" spring compression over your figure.

Edit
Here is the complete spring/damper assembly, the length of the Commando stanchion is represented by the white plastic strip, cut to: 23.161" which is the Commando stanchion length according to the NOC website info, (I do not have a spare so I cannot verify the length, according to the Norvil parts list it's 23.250" and from a previous post, one of our members found them to be as long as 595mm, 23.425"),. The spring measured: 18.575" free, 13.25" coil-bound, giving 5.325" of free movement. When fitted to the damper assembly the spring is compressed approximately .475" thus leaving 4.85" of free movement.


The 23.161" "stanchion" strip is set to the correct position relative to the spring/damper assembly with the upper stanchion end 0.5" below the cap nut hexagon.



At the lower end, the distance between the stanchion and the bottom of the damper body is 4.92".


According to the fork cross-section diagram,the lower end of the damper fits into a recess in the slider . I have no actual dimension for the recess but from witness marks on the damper it appears to be approximately .30", which must be subtracted from the 4.92" figure, thus leaving 4.62" of free space below the stanchion, if so, then according to my measurements at least, the spring with 4.85" free movement would not become coil-bound before the stanchion bottomed in the slider.

Here's Greg Fuath's forum post with pictures of measures that differ from all the above some, just like expected from a going out of business end of BI Golden age Norton. Note that everyone else in the world moves the damper holes just above the damper tapper lip but hobot who staggered them higher and less vent area to boot for gopher hole silent soft bottoming and top out ease. My suggestion to get the top out stop w/o extra sleeve bush in there with out over length to compensate for the fork variability is put in ~2" longer damper rod and put in a sponge or very weak spring spacer so sag height remains stock and spring don't rattle on full 6" extension, which wouldn't affect any thing you' all are used to with just 4.5" travel. Don't try the fork with a variable rate valve spring in there or may lead to some depression with what you'all are used to.

norton-roadholder-modifications-t3645.html

Or...simply replace with the Lansdowne kit!

http://www.lansdowne-engineering.co.uk/three_3.html

Not a bad I idea I hear tell, too bad its only Norton on the outside is all.