Front Bilstein dampers fitted upside down...

[Nick Bassett]

My yr 2000 Superlight R has the front Bilstein front damper units fitted upside down and AFAIK has had since the car was built 22 years ago.

Yesterday a fellow Caterham owning friend was looking at them and suggested they had been fitted incorrectly and should be the right way up. He said only race dampers can be fitted upside down.

Car handles fine and presumably the previous 5 owners were happy with handling too. Car was built by a Caterham employee (Not Caterham) for the first owner.

Just keen to know what the truth is?

Thanks

[SLR 11]

My 1998 SLR also has them upside down... I asked the same question on Blatchat some time ago and most respondents said it was fine...https://www.caterhamlotus7.club/forum/techtalk/bilsteins-upside-down-0

[SLR 11]

My 1998 SLR also has them upside down... I asked the same question on Blatchat some time ago and most respondents said it was fine...https://www.caterhamlotus7.club/forum/techtalk/bilsteins-upside-down-0

[aerobod - near CYYC]

I've always run them on my R400D upside down without problem, to enable easier adjustment, reduce accumulation of grit where the piston meets the seal and reduce the unsprung weight very slightly (with the body side being a bit heavier than the piston side).

[7 wonders of the world]

Mono tubes normally have a floating piston which has a nitrogen charge to reduce aeration these are fine to be inverted in order to reduce unsprung mass, stock dampers are twin tube design which are not pressurised and so should be fitted in the conventional manner.

 

[Nick Bassett]

Thanks for replies.

So, it would seem we have a split decision!

I'm assuming my adjustable standard Bilsteins are twin tube and therefore (according to 7 wonders) should be fitted the correct way up?

[Richard Price]

I'm assuming my adjustable standard Bilsteins are twin tube and therefore (according to 7 wonders) should be fitted the correct way up?

No. Bilsteins are monotube. 

[Nick Bassett]

 

Thanks Richard, but in another thread '7 wonders' mentions that standard Bilsteins are twin tube and therefore need to be fitted the correct way up. My adjustable Bilsteins are not of the race type, therefore I assumed them to be of twin tube construction? Or is that incorrect?

The other thread I mention can be read here:

https://www.caterhamlotus7.club/forum/techtalk/bilsteins-upside-down-0

[7 wonders of the world]

Race Billes are mono tube, stock steel ones are twin tube - not sure which version you are running

[Richard Price]

"Race Billes are mono tube, stock steel ones are twin tube"

No. I cut up a standard Bilstein a few years ago and it was definitely monotube.

[7 wonders of the world]

That's interesting Richard, I spoke with a guy a Bilstein just over a year back about servicing them and the conversation got onto 7 dampers and he said the OE units were based around the B4's twin tube.

I might have a old bent unit somewhere might need to deconstruct it.... 

[ChrisC]

When the club was invited to the Caterham Technology Centre, not long after the 160 was launched, they showed the how they had changed the values in the dampers for that model.  They had a damper there where they showed the process.  They also explained only mono tube dampers would work on a 7 due to the weight.  Doesn't mean they haven't changed since.

[aerobod - near CYYC]

Twin tubes are also problematic at angles of 45 degrees or more from vertical, so the inclination of the front dampers would put them close to that on a wide-track front suspension. Conceivably the rear dampers could be twin tube and the fronts mono tube.

[Simon.Rogers]

It is actually important to find out if there is a floating piston in the Bilstein.  I have never cut one open to find out.

If they are emulsion dampers which is entirely possible then they should have the body at the top so that the piston can sit in the oil until it becomes the emulsion.