How to replace front air suspension?

[Stan]

Good day

I’ve heard about people replacing the original air suspension on the front forks with regular.
So just wanted to ask what I would need and where it’s best to buy it from?

[Scott-(Altoona, PA)]

Here is a link to the AVA Home page/Tech Center/XII section, search down the page till you find the article titled "Installing Progressive Fork Springs". That should offer some help and answer some questions for you!
Welcome and please feel free to ask away, I had to ask lots of questions and still do.
Sorry I can't offer any personal advise as I still have the factory air suspension on my XII.

[Stan]

Thank you Scott. But that link doesn’t seem to be working. I also tried to put the title of the thread into the search, but it failed to bring it up.

Incidentally I typed ZG1200 Voyager springs into the search engine and all the results seem to be in the states. I can have someone bring them other for me, but if anyone knows where I can source them in England it would make it that bit easier.

[VoyKimmer]

https://www.progressivesuspension.com/p ... spring-kit

You can get them shipped anywhere in the world. Many motorcycle parts companies carry them. Less than $100. Make sure you leave out the filter and spacer when replacing them.

[Stan]

Thank you so much for that link.
So after installing them will the air suspension no longer work?

[Mr Jensee]

That is correct Stan. To change the amount of rebound go with a light oil in the forks.

[SgtSlag]

To answer your question about the air assist no longer working... Yes, it will work, but it is not needed. The Progressive Springs are dual-rate springs. Take a look at the coils, and you will see that they are wound tighter, at one end, and looser, over the majority of the length. This gives two compression rates: the looser portion will compress more easily, then the tighter winding will take over, slowing the compression speed, as if the spring was stiffer, overall. This is why they call it, dual-rate, as it functions like two separate springs of different strengths. Some rear shock absorbers actually have two different springs, stacked on top of each other, separated with a washer (do some shopping on motorcycle shocks, and you will see examples of this in the online catalog photo's). Progressive just molded the two springs into one.

The OEM system relied upon air pressure to give you a stiffer compression rate, assisting the uniformly wound springs. The air pressure was serving as the more tightly wound portion of the springs. With a dual-rate spring, the air pressure is not needed -- it can still be used, but it is unnecessary. Some folks tried adding air, and found it too stiff; others use it routinely. It is a matter of personal choice.

Back in the 1970's, possibly earlier, and later, it was standard operating procedure to use automotive Dexron ATF (Automatic Transmission Fluid), typically Dexron I/II/III/IV/V (V is full synthetic, lasts twice as long -- 4 years; Type IV/V are backwards compatible with I-III), for fork oil; other ATF formulas (Ford Type F, for example), are quite different, and I've never seen anything but Dexron used/listed/recommended The reason is quite simple: Dexron ATF is a high detergent oil, with a viscosity of 8, all day long, regardless of temperature. The thermal stability of the viscosity, is identical to proper Fork Oil: no matter the temperature, they maintain their viscosity level, until they reach their thermal breakdown temperature, or they wear out over time... The high detergent levels of Dexron ATF are a boon, as they keep your forks' internal parts squeaky clean, until the oil wears out (typically, every two years). if you use Dexron ATF, no flushing is necessary when you change the fluid, every two years.

Fork Oil viscosity recommendations for the Voyager is typically 10, but I use Dexron ATF, at 8, with Progressive Fork Springs, without issues (zero air), riding two up, 98% of the time. Your mileage may vary. The Dexron ATF sells for around $5-$8 per quart; Fork Oil sells for $12-$20 per quart. Dexron ATF is available, in the States, everywhere engine oil is sold; Fork Oil is a specialty item, only sold at motorcycle shops. Your bike, your choice. Hopefully this helps you to make an informed decision. Cheers!

[Stan]

That was a lot of really useful information. And cleared up a lot of questions for me.

I have found the original shocks to be just too soft. And now one of the seals has broke for the second time in a year. I’m not shore; it might have been because I put in a little too much pressure, but it wasn’t that much.

I don’t know it just seemed like it might be a good idea to put in the springs.

Do the springs stiffen up the ride compared to the original?

There is a gentleman on another old thread who recommends these sonic springs saying they make for a stiffer ride.
http://www.sonicsprings.com/catalog/ind ... d1e199860b

[SgtSlag]

Can't say how stiff Progressives are, compared to OEM -- I replaced them soon after I got the bike. I replaced the fork springs, and the rear shocks, on my previous bike, and fell in love with Progressive equipment. I hate messing with air, especially low pressure, 7-10 PSI, like the front forks required. Mine leaked air pressure quickly, as well. The improvement on my old 1979 Honda 750, was amazing (replaced OEM shocks, around 30 years old when I pulled them, one shock had started to leak oil, so they had to go). From what I've read here, the transformation on the Voyager is considerable, as well. Most folks label it as a, "vast improvement."

With Progressive equipment, no air, no muss, no fuss. But, if you really want the best, you need to open your wallet, and go with something like Race Tech springs and cartridiges. Ohlins shocks, with an external oil reservoir, will put the Progressives to shame. Going that route will cost you more than US$800, in all likelyhood. Is it worth it? Well, from what I hear, Yes. Too rich for my blood on my '93. I should, though, considering we ride two-up 98% of the time... Just wish I made more money, so I could afford such luxuries. Cheers!

[Stan]

That’s interesting about the race tech springs. But I don’t have that money to spend right now either.
A previous owner had already replaced the rear shocks. I forget what they are though.