Just put HD Premium shocks & Progressive Monotubes on my 2011 Street Glide.

HD recommends a pre-load setting of zero for a solo rider of my weight (185lbs.).

However, I find the bike to be more comfortable and better handling with five full turns of pre-load.

Is there any disadvantage to increasing the pre-load setting?

Thanks

 

I can answer your question, but I am very interested in what you think of the shocks if you wouldnt mind sharing.

 

The part where it says "recommends" is your clue. It's just a starting point. Do what is best for you.

 

I got these shocks on mine as I was fed up the the standard air versions that I had on my Ultra Ltd and UC before that. So my new SG got them from new and it is much better, I'm about 230lb and started with the preload up pretty hard as thats what I used to do with the air versions.

Anyway soon realised it didn't need anywhere near so much so now its on a low setting, of course its also a lot easier to dial in/out than the air.

 

The ride will be stiffer is the only difference.

 

Fit the ride to you, You aint hurting any thing.
You may want a different settings in the twistys but thats what adjuster is for. Enjoy what I'm sure is a way better ride.

 

I weigh in at 220 and I have found the ride is better at 2-3 clicks than with no preload. I have also found that there is a break-in period on these shocks, it seems that the more I ride them the better they work.

 

To answer your question, yes, there is a disadvantage. Preload has only one function: to set ride height (sag).

If you increase preload on any spring above what it should be, ride height will be higher (sag will be lessened) which can cause your suspension to "top out", which can potentially lead to damage to suspension components. In other words, the suspension can over-extend.

Generally speaking your pre-load should be set so that the wheel travels upwards from full extension by 1/3 of its maximum travel while you're sitting on the bike.

Contrary to popular belief, pre-load does not affect the stiffness of the suspension, that is the function of your spring (be it single-rate, dual-rate, or progressive).

That said, there is an indirect way that preload can affect handling. Say, for example, that you increase preload on the front but not the rear--now the front will ride higher in comparison to the rear than it did previously. This, in turn, means that you have more rake and slightly more trail than before, which increases stability. The reverse is also true--if you increase preload on the rear and decrease it on the front, the rear will ride higher while the front rides lower, which decreases rake and trail and makes the bike "tip in" more easily. None of this, of course, in any way changes ride quality or stiffness (unless the setting is so extreme that you're hitting bump stops). Just handling.

Now if you adjust compression and rebound damping, well, those will definitely affect ride quality/stiffness.

 

It's just a starting point, put it where you like.

I put them on my last bike and set them at the 230 lbs. recommendation.
I ride solo 99% of the time.
I can’t tell any difference when my bags are full, Tour Pak on or off, skinny rider on the back.
Now the stock air shocks had to be adjusted all the time.

 

If that is the true definition of preload, then it appears as though HD is using this term incorrectly, with regard to their Premium shocks.

Per the description on HD's web site:
"The compression and rebound damping is split between the two shocks - compression on the right and rebound on the left. This design balances the load of each shock; stiff spring with rebound damping on the left and soft spring with compression damping on the right."

They further explain:
"A simple **** behind the left saddlebag allows the rider to conveniently modify the spring preload via a hydraulic adjuster."

While I'm in no position to contradict anyone on this subject, I don't think that the **** on the left Premium ride shock effects ride height when adjusted. If it did, the bike would be lopsided, as there is only one adjustment **** per pair of shocks.

From HD's description above, it seems as though the adjustment **** on the left shock controls the rebound dampening only.

Perhaps HD is erroneously using the terms 'preload' and 'rebound' interchangeably, when they should be properly used to describe two different effects?

Thanks