BX16V.com Forum

Does anyone know if spheres deteriorate if not used. If so, I may well put my new ones on the car now. Secondly, will being on the car accelerate their demise. What wears them out, use and time or mainly use?
When I say use, in my case it is not thousands of miles per year, more like 10's of miles for me.

pressure and or air. In storage the the natural air slowly permiates the diaphragm and helps the nitrogen escape. In the system with LHM against the diaghram the effect is slightly slower, until you start pressurising and depressurising the LHM at which point the diaphragm begins to weaken and let air through.

This is at least my understanding. Explains why they die on shelves and why they die on the car, and why i don't like to regas spheres!

Yes, they do deteriorate in storage. The Nitrogen will can slowly leak out although it has to be said that this would probably take some considerable time.

I believe the nature of the Desmopan rubber diapragm that seperates the Nitrogen from the LHM is that it it remains flexible in use but will stiffen if unflexed, which will mean spheres stored for a long time are likely to fail rapidly (if not instantly) when fitted as the hardened rubber fails.

I bought a pair a few years ago which were stamped with a date 18 months previous and one was dead when fitted. However, I also fitted a new sphere to a 16v last year that came in the boot of one i bought 7 years ago and it was fine!

The other downside to buying but not fitting is: If they're dead when you fit them it's too late to get a refund!

My advise: theres no real rule of thumb. What do you do? Junk the perfectly good ones you have fitted already in favour of the new ones, or take your chances on changing them when you need to? Not much to lose i think.

Cheers, Jay.

Thank guys, I will fit the new ones as there seems nothing to lose. I bought them off ebay a while back so who knows.

they should be date stamped so at least you'll know how old they are if you take a look!

Vanny wrote:they should be date stamped so at least you'll know how old they are if you take a look!

Just looked Vanny,
One is dated 0ct 05, I have had them a couple of yrs. Wonder if they will be better than the ones I fitted in May 95 (I know cus I dated them!)
Will fit and see.

The diaphragm is made of a material which has very very tiny porous holes, the gas escapes very slowly through it, the process is called
molecular diffusion.
Shelve life can be subjective , I have used spheres which were on the shelf for 7-8 yrs and when fitted they were OK.

As said I don't think you can really gauge the "shelf life" of a sphere, it is more a case of try it and see how it feels.
I do think regassing old spheres is not really cost effective as the diaphragm must deterioate over time.

Cheers
Luke

I fitted the two front and they are fine. I had an accumulator sphere also, fitted that and also OK. The one on the car was good but clicks seem less frequent now so pleased all round.

Car has been running well, can't believe how well.