It's a good question, that still really hasn't been answered in my opinion.

 

Well if your measurement of damper travel is correct. The math is quite simple and tend to give you reason.
That's only if the dampers can only travel 2" as you said, which is a little more than 5cm. I find 5cm of damper travel ridiculously small!
I know by tweaking the preload you are only trading bump travel (increased preload) with droop travel (decreased preload, duh!). But it seems there is not much to trade here.
Also, I think having a rear wheel in the air inside a corner will have dramatic consequences on your traction, which is sad.

 

Not referring to you specifically. It just seems to be a common trend I've noticed lately. and its not like it's specific to people asking about Ohlins although I've seen way too many Ohlins DFV threads asking the same questions.

 

It is pretty silly to think you must understand how something works to use it.

People find good setups and duplicate them. This is extremely common in autox/tt.

 

I heard you brother and completely agree. I see too many cars sitting on Ohlins and KW's at the local car meets that have never seen a track. Another thing is, I understand you get what you pay for but I have a hard time believing the average board member knows the difference between what a premium damper and a cheap damper does differently on the track, springs aside. One of these days I want to do a blind study with track times, just for grins.

To the OP, No disrespect expressed or implied above. Any consolation, our FTOD at the autoX here is on Ohlins DFV, I have not driven on them personally but I had a front row show of what they can do and I was impressed. PM Gernby, he might be able to lend some tips.

 

+1

So what's the verdict here? I know Urge is a well known dealer who sells Ohlins kits, and is very educated on Ohlins products. He says preload should not be that high, and recommends the 2mm preload. Andrew and Steve both say they run Ohlins recommended preload with no issues. I've also read others running recommended settings with no problem.

Urge, do you happen to have any further comment as to why thomsbrain and Gernby recommends 30mm of preload? Thanks.

 

For the record I didn't even measure my preload. I simply put everything together and then snug the spring up so it wasn't loose. I'm probably somewhere between 0 and 2mm of preload.

 

I've been running the Ohlins recommended 2mm preload with no problems. It's difficult to get an exact 2mm measurement so as long as the spring is not loose with no load on the dampers then it should be ok.

 

To be clear the question is whether or not there is any advantages to running more than Ohlin's recommended preload in the rear in terms of actual wheel travel. Not to mention possible disadvantages like limiting rebound travel and putting unnecessary stress on the damper even when the car is lifted off the ground. That is why I asked if people who have decided to preload the rears so much have measured their rebound travel.

 

All, I work with Gernby on a variety of Development and we are even licensing his Gern Pipe. He is a good friend. I just texted him and reviewed his thread.

He uses 0.08" or 2mm Preload on the Front and 0.6" or 15mm Preload on the rear. His rationale for the 15mm preload is to put the piston in the middle of the shock. He wanted to go more but was limited by ride height. IMO, I think 15mm is a little much, but Gerby has numerous FTD against much more modified cars running 2X higher cost shocks.

Your milage may vary.