Trials Australia Forums

Does somebody know why the new betors are upside down compared to old betors and falcons? And then if that is irrelevant to the way a shock works why cant some brands be inverted?

Some shock designs have a device that separates the oil from the gas. They can be used either way up.
Standard Falcons have nothing separating the oil from the gas, so if you mount them shaft upwards, the damping piston is in the gas zone. The damping is from oil moving through flow restrictions in the damping piston, and gas has a much lower viscosity to oil, so if the piston has gas going through it, there is almost no damping.

David is correct in his description however most of the Falcons and Betors that have the gas valve on them are what is known as emulsion shocks. That means that when the shock starts to move up and down the oil and gas mix together to form a frothy mixture that fills the hole inside of the shock and in theory this allows them to work either way up. Falcon did claim that their shocks could work either way up, I've not worked on any Betors or know what they claim but for my money I would use them upside down because the gas does seperate from the emulsion to a certain degree after a time of no use and also there is less unsprung weight mounted that way. It's a pitty people that are full of hot air don't let the gas seperate after a time of no use!!!!

Cool - thanks Tricub. Might be fun just from a discussion point of view :). "Hey your shocks are upside down?" "I know, they are upside down shocks!" or " no their not, the stickers are upside down" etc Hmmm might be time to go back on the medication....

Betor shocks are a direct copy of what Falcon were making around 20 years ago, but using cheaper materials and not re-buildable. These shocks are emulsion type, and while Betor do not have anything to separate oil from gas when fitted body down, Falcon do separate oil from gas if body down fitment is required.

For what it's worth the Betors I own dampen either way up ( I use them resivour on top) and my Falcons have little or no dampening with the resivour on bottom but work well the other way around.

Takhli44 wrote:For what it's worth the Betors I own dampen either way up ( I use them resivour on top) and my Falcons have little or no dampening with the resivour on bottom but work well the other way around.

Have you ever tried the Falcons body at the bottom and taken it for a good ride? What pressure are you using in them, could have something to do with the oil turning to an emulsion.
Most of the Falcons that I have repaired where on VMX bikes and mounted body up but the local Falcon agent tells people that they can be used either way up. The only style that I have seen didn't have floating pistons to seperate the gas and oil but it's been about five years since I've seen a pair as they have gone out of favour a bit with the MX guys.

For Reinalds benefit, the devise that is used to seperate the oil from the gas is called a floating piston. This piston is loose inside the shock body and gets fitted before the main damper piston goes in, it generaly has a "O"ring seal around it and some form of teflon band around it as well. The floating piston doesn't move that much as it only has to deal with the oil displaced by the shaft moving in and out. One draw back with this type of system is the fact that you have to make the body a bit longer to fit it in or reduce the travel to suit. Most of the long travel twin shock MX bikes have a remote reservoir which houses this floating piston with gas on one side and oil on the other. The early Yamaha mono's that had the bulb shaped thing on the end of their shock used a rubber diaphragm to seperate the oil and gas. The diaphragm in my opinion is the best system as it offers no friction in moving as does the "o"ring sealed floating pistons. The rest of those early Yamahop shocks were dreadful but that's another story.

No I have never taken the Falcons for a good ride with the resivour on the bottom. I am using 80 PSI after what folks on this forum have told me. I always run resivour on top. Just noticed when I had the springs off to change positions that they didn't dampen other way around and made an apparently mistaken assumption.

I'm getting an education from you guys, thank you.

I know the owner of Falcon very well, and will ask about inverting his shocks next time we talk. I do know that he always fits separator pistons to shocks intended to run body down though.

FM350 wrote:I know the owner of Falcon very well, and will ask about inverting his shocks next time we talk. I do know that he always fits separator pistons to shocks intended to run body down though.

Makes sense to me to only run the emulsion type shock inverted but I have seen them working with the body down and they did work poorley until you bounced them up and down a few times. It will be good to hear it from Falcon though.