...tumbleweed

has been blowing through this blog for far too long. I could blame pressures of work (somehow I've ended up with four jobs at the same time) or the fact that some of my creativity has gone commercial. Anyway, the pretty picture above is one of the fruits of all that labour.

One of the four jobs has been developing suspension kits for various people. The problem with doing this is that you often have to make do with whatever a damper manufacturer has sent you, particularly in terms of adjustability. Sometimes you get lucky and you can get the dampers set exactly how you want them and other times you just can't get the rates you want.

So, in finest engineer fashion (i.e. slag off the competition, insist you are the only person on the Earth who can actually do the work properly... have no dress sense or sense of rhythm), I've decided to fill my gap by designing a damper to work just the way I want it. I've even got a manufacturing partner lined up, which is a degree of organisation I'm not renowned for.

So, quick run down of the features:

1) It's a through rod damper. Virtually all dampers aren't, so as the piston moves into the body, the shaft it's attached to changes the working volume, which has to be accommodated. Two common methods are employed. Either you have a second concentric chamber as a reservoir (a twin-tube damper) or you have a second piston with a gas spring to one side which can be compressed to take up the slack (a monoshock). This one has the piston in the middle of the shaft and a seal at each end of the working chamber. As the piston moves, there is no change in working chamber volume. Very useful as it means the design can work on low pressures and therefore react quicker to changes in velocity. It also means that the seals can be off the shelf O-rings and DIN seals.

2) No internal valves. The attractive block bolted to the side carries all the valves. So if you want to change something fundamental, you don't have to strip the whole thing down, you can simply depressurise the unit and swap the valves about. Fluid can only flow from one side of the piston to the other via the valve block. This means you get a large flow of fluid and it's far easier to control a large flow than it is a small one.

3) No shims. Commonly, dampers use thin sheets of metal blocking holes at provide the damping force. These tend to be horrendously non-linear. This makes tuning an interesting affair and lots of rebuilding tends to go on. I've engineered this using simple tappet valves and adjustable orifices.

4) Six way adjustment. OK, this is probably overkill. As well as controlling the gradient of the Force-velocity curve in high and low speed situations, you can adjust the knee point where the two curves switch over. All of that adjustment comes without stripping down valves, which makes it ideal for someone with very little time. Of course having six different knobs to twiddle makes it a nightmare for someone with no idea what they're doing.


I've also tried to make the unit as manufacturable as possible. Similar units from Koni and Ohlins retail at around £500 each, and I'm trying to get the price point to something around 40% of that and if any machine shop with a CNC mill and lathe can churn these out in their thousands, then I'm laughing.