Air forks

[Clyde the ape]

Are there any advantages to air forks?  What year/model cb are they found on?

[Cabreco]

Clyde the ape wrote

Are there any advantages to air forks?  What year/model cb are they found on?

I haven't found any. I set my psi at 17 & leave it alone. My 81 rides fine.

I also have a Yamaha Venture with an air ride suspension & I'm changing the forks to progressive springs. It seem the weight of that bike makes the front very un smooth!

[TOOLS1]

I know they are on the DOHC bikes, but I am not sure of the advantages.
TOOLS

[sgtslag]

The air is supposed to give a better response, than just oil and springs, but many folks chuck it, in favor of progressive rate springs, instead.  I own a '93 Voyager touring bike, which had OEM, air-assist, front forks, as well as air-assist rear shocks.  I removed them, and put on Progressive Fork Springs, and 12-Series shocks, dual rate springs, no air in either front, or rear, anymore...  Many, many other Voyager owners have done the same, and none have regretted it.

The disadvantages to air are:  low PSI required in the front, usually around 7-12 PSI, requiring a hand pump to avoid blowing the fork seals; the rear typically requires 30-45 PSI, which can be quite harsh to achieve with a hand pump; the rider will need to carry a low-pressure gauge (<15 PSI), as well as a more normal range pressure gauge (20-60 PSI); there are rather long, pressure hoses on many bikes, routing a fill point to a convenient(?) location for access -- more crap to puncture, lose a seal, cost you money to fix.  Air-less systems are simpler, and require far less maintenance:  adjustments are usually presets on the springs, and perhaps a rebound damper setting -- easy, no muss, no fuss, set it and forget it.

I replaced my OEM, non-air shocks, on my CB750K with Progressive 12-Series Shocks -- incredible ride!  Just be sure to replace the Fork Springs, with Progressive's dual-rate fork springs, at the same time:  they work together, and if you only do one, it will throw off the other.  My '79 rides like a brand new, 21st century, bike, not a 33-year-old bike, from the 1970's...  It handles superbly, as well, it is not just for comfort.  Cheers!

[shinyribs]

Sarge,you are always a wealth of information. Thank you sir.You sold me on progressive shocks/springs months ago...i'm still saving!

[Cabreco]

shinyribs wrote

Sarge,you are always a wealth of information.

And a wealth of money in the wallet <lol>...The rear progressive is over $400 shcarols on the Venture!
Saving up for that rear one too!

[sgtslag]

My bad!  I meant the 12-Series shocks, not the 412 shocks...  The 412 Shocks are much more expensive.

Take some time to shop around for shocks for the CB750's.  I think you will find that there are inexpensive replacements available, typically <$100 for a pair, but you will also find uber-expensive, Ohlins brand shocks, complete with an external oil reservoir...  The Ohlins are really only necessary for racing, but many folks (with excess disposable income) put them on their street bikes, and touring machines.  My point is that the Progressive 12-Series are not terribly expensive, as shocks go (I believe, but I do not know, that they are far superior to the <$100 units...).  They are actually on the lower end of the scale, as they are sealed units, which, realistically, cannot be re-built, and you cannot change their oil.  Like I said, though, Progressive has a loyal, well deserved (IMO), following.  Cheers!

[slownugly007]

Hey Sarge, I was curious about changing over to a non air fork on my 81? I was taking apart my forks and it seemed to already have progressive springs?? Not sure if that was stock or an aftermarket upgrade by the previous owner, but the springs definitely have a progressively wound coil. If I swap over what can I do about my fork nuts? They are huge, bulky and limit me from installing my new master cylinder with drag bars.

I was thinking about swapping them out with a set from an older bike, but my forks are 37mm and I know most other cbs run 35mm. Or maybe get an old set and cut the hex head off and tig it on to my fork nut body? Any advice is appreciated! Thanks!