fork springs

[chopwatchagot]

After reading Sucubus situation with the steering head bearings, I decided to go out to the garage and check those on my '80G, since it's up on the stand getting a good going over and an influx of "new" parts from the '79 donor bike. Sure enough those bearings needed some attention. I got that problem solved with a good cleaning but before I put the whole thing back together I decided to check the forks. didn't seem like a whole lot of damping action when I bounced on 'em so I took 'em apart to see what could be done. I've had a bunch of old bikes and most of them have not had such good maintainance in the front end department. This one is no exception. The PO lived down a LONG dirt road in Utah and everything is full of fine red sand or dust. After I got the sludge out of the tubes and cleaned everything I checked the spring lenght. Clymers manual says the 80 & 81 should have a free lenght of 20.31" but mine are only 19.5. Is this really a big problem?

[prometheus578]

Big... no.
Are the springs tired... yes.
I'd say a good 90% of us are in the same boat. If you want to replace them, go with Progressive Springs.
(no... I'm not starting THAT one again!)

[xschop]

come-on

I haven't seen anybody post on this topic. You can restretch the spring. I did one set by straping plumbing tape to a 2x4 with one end of the spring and a 45lb olypic weight to the other and set the height at 33 inches(works perfect) you can just let the weight of this apparatus restretch the spring back to stock in 20 minutes....

[prometheus578]

"Ok, I'll play."

The spring is shorter because it's lost some of it's tension. It has weakened and sagged with use and age, like most of us. One can stretch it back to it's former length, but that's about it, as it's bounciness will never return to what it once was.
If 45 lbs of weight will stretch them to length again, what's gonna happen when you put them back in the forks and put 500 lbs of bike on top(not to mention cornering, pot holes, and such)
Just an opinion... I've never stretched springs before, but have replaced quite a few.

[Erik the Red]

ooh, ooh, me too!

Here I entirely agree w/ Pro. Here's another way to explain it: The spring shortened because the action of loading and unloading it weakened the internal (molecular) structure of the spring, thus causing it to sag -it can't hold itself up anymore. By stretching it back out, you are further disrupting the structural integrity of the metal.

Take a thin piece of metal for example, like a metal strap that holds copper pipe in place inside a wall for plumbing fixtures. Bend it. Then bend it back. It doesn't go back to its original shape. Bend it back to the first bend. And back.... Essentially, every time you do this it's weakened a little more, until it fails (i.e. breaks).

Same deal with any metal. The spring might be back to its original length, but its properties are now different. It can't damp the same amount of load as effectively.

[Pat Kelly]

I suppose you could stretch it to the desired length and then re-temper it (or whatever process they use to turn a twirlly wire into a spring). Unless you have a forge/oven in your garage (Ken T..... do you?) it would be cheaper to buy some new (Progressive brand, hint hint) springs (along with a Tkat bork brace, new seals, and new bork oil).
Your bike will love you for it

[chevy45412001]

hey pat

were did you find that bork oil you speak of ? checked all parts houses and bike shops they all looked at me kinda funny. (just kidding)

[xschop]

restretch

the restretch on any spring works. I also restretched the diaphragm spring in the carbs. But the fork springs are still going strong.

[chopwatchagot]

Ok, at first I thought this must be one of those newbee initaion tricks, ha! stretch fork springs?,(like sending your girlfriend to the parts store for a quart of oil pressure) but I tried it anyway. 50# for a couple of hours and they gained a 16th of an inch. My degree in S.O.P. engineering wants to agree with Prom. and Erick the Red (a real engineer) so I don't think I'll try too hard to restretch them. The new PROGRESSIVE spring idea sounds better in the long run, but thanks for the info anyway, chop.
With the air forks, how much do the progressive springs inprove the ride?

Dean

[50gary]

Just to be a second opinion, on brands "Race Tech" or "Traxxion Dynamics" have high grade replacement springs. Both have excellent web sites check them out.
Cheers, 50gary

[DiverRay]

Progressive will send out VERY GOOD instructions with the springs. If you do as they say, you don't run ANY pressure in the forks. Just put the caps on to seal, and you should be good. You MY want to go to five pounds or so of air when loaded, but that will be up to you.
I DO run the progressive springs, and with the TKat brace the daily ride handles very well, thank you.
Ray

[GNEPIG]

.. after the new progressive springs, i dont run any air pressure in mine either, but i dont have a large chunk of fairing and other stuff hanging over the front end either... progressive suspension springs cost about 70 bucks and are real easy to install. you dont need to add PVC extentions for the Standard models.
..i have found 10w oil to work the best for my bike- and i am an agressive rider. i have the TKat fork brace on mine also.

[prometheus578]

"Yea, but... when putting in the progressive springs... do the tight coils face up or dow....."
"Owww! Who slapped me?"

[pggg]

The answer is - check out the progressive back shocks

[pggg]

Tight coils on the TOP for forks. Everyone has their progressive fork springs installed the right way - right? Right?