Author Topic: Are these fork springs shot? (Read 5645 times)

messeduptriple · « **on:** December 27, 2012, 05:18:02 PM »

Just curious i have no idea how to tell if springs are bad or good? How can i tell?
Thanks

Cristian
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harisuluv · « **Reply #1 on:** December 27, 2012, 05:35:46 PM »

Looks like they have some asymmetrical compression from wear. I have a set of springs from a 7k mile bike I will take a pic in a second so you can compare.

harisuluv · « **Reply #2 on:** December 27, 2012, 05:39:51 PM »

Aw nuts, I remember I just took them along with some other parts to the shop the other day. Will take a pic next time I am there.

messeduptriple · « **Reply #3 on:** December 27, 2012, 05:47:29 PM »

Quote from: harisuluv on December 27, 2012, 05:39:51 PM

Aw nuts, I remember I just took them along with some other parts to the shop the other day. Will take a pic next time I am there.

thanks!

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messeduptriple · « **Reply #4 on:** December 27, 2012, 05:48:55 PM »

So are they ok to use or just replace them?

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trueblue · « **Reply #5 on:** December 27, 2012, 05:55:27 PM »

Measure their free length and compare it to your manual

MCRider · « **Reply #6 on:** December 27, 2012, 06:05:14 PM »

One is upside down compared to the other. They are "dual winds". Part of the coil is tighter than the other to give it a 2 stage compression. Light to flitter over the small bumps, then they get stiffer when compressed far enough.

In between a straight wind and a progressive wind. Never knew of OEM wound that way, but i know little of many models.

Never had them in the bike? What bike?

Rule of thumb on OEM suspension equipment from that era is that its all junk from the factory. If you can fiind replacements do so, as that is what one would have done when they were closer to new, anyway. Assuming it is a 70s era jap 4.

messeduptriple · « **Reply #7 on:** December 27, 2012, 07:22:34 PM »

Quote from: MCRider on December 27, 2012, 06:05:14 PM

One is upside down compared to the other. They are "dual winds". Part of the coil is tighter than the other to give it a 2 stage compression. Light to flitter over the small bumps, then they get stiffer when compressed far enough.

In between a straight wind and a progressive wind. Never knew of OEM wound that way, but i know little of many models.

Never had them in the bike? What bike?

Rule of thumb on OEM suspension equipment from that era is that its all junk from the factory. If you can fiind replacements do so, as that is what one would have done when they were closer to new, anyway. Assuming it is a 70s era jap 4.

great info. Thanks!

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Steve_K · « **Reply #8 on:** December 29, 2012, 07:49:15 AM »

I think that those are aftermarket fork springs. They look like Progressive fork springs. They work well on my 750. Tightly wound ends should be to the bottom of fork. May need spacers under the fork caps. They should measure the same length.
Steve

MCRider · « **Reply #9 on:** December 29, 2012, 08:47:03 AM »

Quote from: Steve_K on December 29, 2012, 07:49:15 AM

I think that those are aftermarket fork springs. They look like Progressive fork springs. They work well on my 750. Tightly wound ends should be to the bottom of fork. May need spacers under the fork caps. They should measure the same length.
Steve

Yeah i never saw OEMs like that either. But truthfully, I haven't seen that many after K2. If so, (not OEM) they are keepers. Then on the other hand, did Progressive make dual winds, I thought they were truly progressively wound?

Then there are schools of thought on tops and bottoms. If you put the tight winds in the bottom you increase the unsprung weight. Also, with the tight winds in the bottom you reduce the amount of space available for the oil, and it moves farther up the tube where it does less (I think) good.

Though I would readily defer to someone who has the word from Progressive themselves.

I know the "unsprung weight" thing is disputed as to rear springs. Some, like IKON, put the tight coils on the bottom. Others, like me, on the top. But with the front springs we have the added issue of the oil.

crazypj · « **Reply #10 on:** December 29, 2012, 09:06:08 AM »

Quote from: MCRider on December 27, 2012, 06:05:14 PM

In between a straight wind and a progressive wind. Never knew of OEM wound that way, but i know little of many models.

I've never seen much else than progressive/dual rate springs in mid 70's Japanese bikes.
They only really went back to short straight would springs in mid 90's when all the 'performance' bike started using cartridge forks, the damping gets 'confused' with multi-rate springs

srbakker · « **Reply #11 on:** December 29, 2012, 09:28:37 AM »

Quote from: Steve_K on December 29, 2012, 07:49:15 AM

I think that those are aftermarket fork springs. They look like Progressive fork springs. They work well on my 750. Tightly wound ends should be to the bottom of fork. May need spacers under the fork caps. They should measure the same length.
Steve

I'm with Steve on that - they look identical to the Progressive springs I had and sold.

Steve_K · « **Reply #12 on:** December 29, 2012, 12:16:34 PM »

Really, it probally does not matter which way is up. When the fork compresses it doesnot care.
I thought that Progressive suggested the tight wound end be placed in the bottom. Did I remember correctly? I don't have the instructions handy. I won't lose sleep on it either way.
Steve

crazypj · « **Reply #13 on:** December 29, 2012, 06:07:33 PM »

close coils at top, higher center of gravity, lower unsprung weight

shinyribs · « **Reply #14 on:** December 30, 2012, 12:13:42 AM »

They definitely appear to be progressives. Doesn't matter which end goes where. All personal preference at that point. Like was said earlier,there should be a spacer to go along with them. About 1'' or so.

Careful when filling the forks with oil. With the closer wound coils displacing area where there is usually oil you can easily overfill the forks.

RSchaefer · « **Reply #15 on:** December 30, 2012, 06:55:23 AM »

For what its worth I asked Hondaman recently about replacing my stock 12K mile springs ('75, CB750F) with Progressives and he recommended against. Said the Progressives were not as good as the stock. Based on the age and my weights (220) Mark suggested adding a 1/2 to 3/4" extender at the top due to the sag of the stock springs and then add Schrader caps and air (3PSI to 10PSI) to dial it in.

messeduptriple · « **Reply #16 on:** December 31, 2012, 05:41:04 AM »

My forks were leaking oil... not heavily but after long rides i could see the oil streak down. When i emptied the fork legs there really wasnt much oil left. I resealed them with new seals and i noticed that when i did the seal last summer the c clip was a #$%* to get flat with the seals but i got it in there... i looked at them when i took them apart and they were a tad bit cocked if i may say.
So i resealed again but used a large flat head to push against the clip when i inserted the clip, worked perfect and lined flat against the seals.
Im wondering if that could make the springs bad??? Bad seals?
* i was going to order new springs but where do they sell good ones? Has anyone tried racetechs??

- Cristian

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MCRider · « **Reply #17 on:** December 31, 2012, 05:58:54 AM »

I wouldn't ascribe any relationship between the seals and the springs. The springs will wear from overuse, hauling a touring fairing around, high mileage and bumps. Mark (HondaMan) says OEM are OK or even better than aftermarket. I'd never heard that before. So, its in the personal preference land. I'd always heard that the OEM were undernourished from day one and need replacement. That's my experience as well.

The seal will float a little in the space provided and can appear cocked and stilll be OK, or not.

Racetech and Progressive are probably the 2 names for fork springs.

Harsh · « **Reply #18 on:** December 31, 2012, 07:15:03 AM »

I am going to go with a set of Sonic Springs. Rich Desmond is very customer service oriented. I have used his springs in my old SV with oem forks then after I switched the front end to a GSXR forks. They always flawlessly. Plus he is a little cheaper that Racetech. I like the feel of a straight wound spring over a progressively wound spring. If you don't see what you are looking for shoot them an email and they will get it.

http://www.sonicsprings.com/catalog/

MCRider · « **Reply #19 on:** December 31, 2012, 07:29:18 AM »

A new Favorite Place.

lucky · « **Reply #20 on:** December 31, 2012, 08:00:31 AM »

Quote from: trueblue on December 27, 2012, 05:55:27 PM

Measure their free length and compare it to your manual

First smart answer.

shinyribs · « **Reply #21 on:** December 31, 2012, 09:11:01 AM »

I got my progressives from the local shop. The box said Progressive Suspension. $78 for the pair. I'm very pleased with them and 8k miles later am still happy with them.MUCH better than stock. OEM might be just fine,but 40 year old springs are just that-old.

MCRider · « **Reply #22 on:** December 31, 2012, 09:37:19 AM »

Quote from: shinyribs on December 31, 2012, 09:11:01 AM

I got my progressives from the local shop. The box said Progressive Suspension. $78 for the pair. I'm very pleased with them and 8k miles later am still happy with them.MUCH better than stock. OEM might be just fine,but 40 year old springs are just that-old.

Progressive with a capital P is the company. progressive with a lower case p is the style of winding. Do you remember were yours progressively wound, dual rate or straight? Just curious.

As to the straight wind comments from Sonic and RaceTech (and maybe Progressive too), seems they apply to suspensions that are otherwise tunable for damping. Unless one installs cartridge emulators, our old pogo sticks are not tunable and I think a progressive spring may still the way to go.

grasscutter · « **Reply #23 on:** December 31, 2012, 09:40:43 AM »

Quote from: trueblue on December 27, 2012, 05:55:27 PM

Measure their free length and compare it to your manual

+100

crazypj · « **Reply #24 on:** December 31, 2012, 09:47:51 AM »

As I posted arlier, and expanded upon by MCRider, Honda et,al.used progressive wound springs from the mid 60's
on many bikes.
External springs were usually straight wound, rear springs often progressive wound
Internal fork springs, almost always progressive wound (in 1974~5 I had a 1967 CD175 with progressive springs

)
The material may be superior on Progressive springs (the manufacturer) but rates are always similar
I have several XS 650 Yamaha's, they all have progressive springs with same diameter wire as Progressive
(Confused yet?)
It isn't anything special.
As pointed out, if your not fitting cartridge emulators, you don't need straight wound springs

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Author Topic: Are these fork springs shot? (Read 5645 times)