|
|
Post by bertman on Oct 14, 2008 14:19:49 GMT -5
|
|
|
|
Post by phoebeisis on Oct 14, 2008 15:24:32 GMT -5
Robert, I installed "air caps" on one of my SR500's in the early 80's-Goki might have been the manufacturer of the caps. They worked fine as near as I could tell. The "knock' on air forks is that the air is supposed to increase friction/stiction. I think the implication was that the seals-now air seals, not just oil seals, were pushed harder against the fork legs increasing the friction/stiction.
Because of the above, most folks ,and manufacturers, use coil springs.
Now that all might be BS because mountain bicycles come with air forks, and they work just fine-no particular increase in stiction that I can feel. Bikes are lighter,so if there was increased stiction it would be more noticeable.
Charlie
PS Just read the link you gave and read what Joniell wrote. I assumed that these caps were period pieces -meaning they were for pumping air-pressure into the forks to act as an accessory spring-stiffen it up. The article is actually about much more modern dirt bike type air relief caps which get air out of the forks-decrease pressure. I don't think anyone would bother putting the air relief type caps on a mild street bike like the SR500?
|
|
|
|
Post by joneill4 on Oct 14, 2008 16:05:22 GMT -5
I have air caps on mine. That's the way I got it. The conventional wisdom now is to get the air out of your forks. Do a search for fork bleeders. Very popular for dirt bikes where you can build lots of heat in the forks. The article that you linked to may hold well for road bikes, but it's not true for dirt bikes ( it was a CRF website). It would probably be true if you had nitrogen in there.
|
|
|
|
Post by colinjay on Oct 15, 2008 1:30:56 GMT -5
I have run "pump-up" air caps on my SR before, as well as on some of my old dirt bikes back in the 70's and 80's. They were an effective way of increasing the the overall spring rate of my forks and gave a progressive effect at the end of the fork travel, preventing the forks from bottoming out. I never had any problem with seal either leaking or with anything that could be classed as excessive stiction. The basic rule of thumbs back then was to run 5 - 6 psi and to never exceed 15 psi. Most of the problems back then with blowing seals and having other seal problems were due to people removing the fork springs relying on air only, at higher pressures to do all the "spring" work.
Both my 350 Bultaco Sherpa T's and KT250 Kawasaki observed trials bike have air bleed caps on them to prevent air pressure building up in the forks and increasing the spring rate above that of the actual springs. It seams to work ok for observed trials, but it takes some getting used to the hissing sound as air exits the forks when you ride over a steap drop.
CJ
|
|
|
|
Post by bertman on Oct 16, 2008 7:13:30 GMT -5
Thanks all. I am stripping the forks this weekend, I am sure that they have never been done before so I would reckon they will be quite "nasty"
|
|
|
|
Post by caferacercarl on Oct 19, 2008 1:55:38 GMT -5
We've been on this topic before in detail, don't run air, notice no bikes come with air forks anymore or anti dive? just use good single rate springs [ stock XS650 spring rate] but technoflex instead of genuine, weld one of the little rebound holes shut and use ATF [or 15w] at STD amount, glorious for 85/90kg. cheers.
|
|
