I need to replace some old Spax adjustable shocks as they were put on backwards by the previous owner. The adjusters were rubbing on the top arm and oil has leaked out.

What spec shocks do I need to buy? Standard or lowered? Is it best to go for the best non-adjustable F4 B36 Bilstein or keep with the same (cheaper) adjustable Spax? If there seems to be not much in it, performance wise then I would choose the cheaper option.

I would like to take the Rossa on a track at some point but I don't think it will be often enough to sway the decision of which shocks to buy.
Also, does anyone know where to get a build manual from? I have NO information at all about the car.

Any advise is eagerly anticipated.

Thanks.

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The gas filled is in referance to what is used in conjunction with the oil. Most shocks are oil filled as this is one of the best mediums for this job, Gas is used to stop the oil from foaming up under hard use the type of gas and how it is used within the shock depends how it works/responds.



thanks to a quick search on google

Neil

Cheers for the explanation. I've refurbished a few bike front shocks so that makes sense, so I've now edited the part that makes me sound completely clueless, although I have just spotted it's still there in your message........doh!

If memory serves me right -- it might not,I worked on dampers straight of Uni in the mid 70s -- its to do with having to accommodate the volume of the damper rod as it goes through its stroke into a sealed chamber. The gas/air contracts/expands as required to accommodate the volume of oil displaced by the rod as it goes through its travel -- in a way acting a bit like a gas spring. In old twin tube dampers the air and oil weren't separated by a diaphragm so when they were over worked and got hot the oil would emulsify and performance would deteriorate drastically. Monotube dampers have the advantage that they usually have a second piston between the oil and gas (usually nitrogen I think) so they don't mix and therefore deteriorate less when hot. Whilst performance is more consistent the downside is that having only a single valve assembly for jounce and rebound limits the tune-ability a little.
Steve

thanks for all this explanation but just the fact that gas replaces the air explains enough to fill in the blanks. I don't want to refurbish my own shocks, I want to buy replacements.

My question was what shocks to use?
Are they STANDARD or LOWERED mini shocks? No-one anywhere seems to know.
It has been confirmed (elsewhere) that I need two sets of fronts.

i am not 100% but i was going to use standard hight ones because i havent fitted hilos to my rossa and have put new rubber cones in for now untill i get round to breaking one of my minis that has coil spring replacements instead of the rubber cones. i would have thought that using a standard mini subframe and suspesion ect, that this would be what is needed. i will try to find out if no one else comes on with the set up they are using.

It turns out that standard mini front shocks for front and rear of the Rossa work. The fronts to be a soft setting so ideally adjustabe. I was hoping to fit Bilstein shocks but they don't do adjustables for the mini so the valve inside the units would have to be swapped out and changed for soft setting valves. Bilstein themselves would have to do this and although I used to work opposite a Bilstein servive centre and tried to get them to help out, after a year they still were not arsed to sell me any. Spax yellow adjustables it is then, like every other Rossa ........but I like to be different (you'd understand if you saw me).

I've been getting a bit concerned about the pounding my wee car has been getting from our he11ishly maintained roads and the crashing and banging is quite uncomfortable (and alarming!) at times. I decided to check out the dampers which are a set of red Spax adjustables (unused but a few years old) that came with the car and adjusting them doesn't seem to make much, if any, difference at all. With the car set at the recommended ride height (5.5" at the front) the distance between the mounting pins for the damper is 270mm and the distance from the tip of the bump stop to the top arm is 30mm. The pin hole distance on the damper fully extended is 330mm and fully closed it is 235mm. So, there is only 35mm of travel left in the shocker and I can tell that the bump stops have been coming into play so 30mm of that travel has been taken up. That leaves just 5mm of compression on the bump stop before the damper bottoms out so it's no wonder the ride has been harsh! I haven't measured the back end because I'd need a ramp to do it properly but I assume that the same applies although there will be a few mm more travel before bottoming out because the back sits 1/4" higher although, having said that, the bump stops look as if they have been working a lot harder than the front presumably because of the weight of the engine. So, to come back to the original posting at the top of this thread, it seems that lowered dampers are required on a Rossa 1 and 2 although I must point out that the damper operating range varies slightly between different makes so some might have a little bit more travel than others.

This means that my long suffering piggy bank is going to get a battering again I don't need (or want) adjustable dampers so I'm looking at a set of KYB gas 'self adjusts' from Mini Spares http://www.minispares.com/product/Class ... ssic/shock which are highly recommended by Keith Calver for both standard height and lowered cars due to their operating range of 324 - 210mm. There is a good article about ride height with the KYBs recommended here http://www.minispares.com/article/Techn ... 2eeefa54e5 .

I fitted a set of KYB Gas-A-Just dampers today and the ride of my car is absolutely transformed I did a few miles on a bumpy back road and managed it without gritting my teeth once! The car is now sitting 1/2" higher all round due, no doubt, to the gas pressure in the dampers but I'll leave it for now to see if it settles - a turn on the HiLos will fix it easily enough if necessary.

When fitting the KYBs I noticed that the front left wheel had come up far enough for the tyre to leave a big scuff mark on the inside of the wheel arch on the main tub probably due to a pothole but it shouldn't have happened. Also, at the back on both sides the handbrake operating arm brackets where the clevis pins for the cables fit on the MGF callipers have been hitting the underside of the buttresses hard enough to break through the gel coat - not good No wonder it felt so bad at times...

Sorry to respond to such an old post, but have only just spotted it. Are you still after a build manual?